/* ===== algebra-hub ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
  :root {
    --teal: #0F766E; --teal-light: #14B8A6; --teal-pale: #CCFBF1;
    --teal-bg: #F0FDFA; --dark: #111111; --mid: #444444; --soft: #777777;
    --border: #E5E7EB; --bg-alt: #F7F7F7; --white: #FFFFFF;
    --radius: 16px; --radius-sm: 10px;
  }
  html { scroll-behavior: smooth; }
  body { font-family: 'DM Sans', sans-serif; color: var(--dark); background: var(--white); line-height: 1.6; -webkit-font-smoothing: antialiased; }
  h1,h2,h3,h4,h5 { font-family: 'Sora', sans-serif; line-height: 1.15; letter-spacing: -0.02em; }
  a { color: inherit; }
  nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    background: #ffffff; border-bottom: 1px solid var(--border);
    padding: 0 5%; height: 68px;
    display: flex; align-items: center; justify-content: space-between;
    transition: box-shadow 0.3s;
  }
  nav.scrolled { box-shadow: 0 2px 20px rgba(0,0,0,0.06); }
  .nav-logo { display: flex; align-items: center; text-decoration: none; flex-shrink: 0; }
  .nav-logo-img { height: 44px; width: auto; display: block; max-height: none; max-width: none; }
  .nav-links { display: flex; align-items: center; gap: 32px; list-style: none; }
  .nav-links a { text-decoration: none; color: var(--mid); font-size: 0.92rem; font-weight: 500; transition: color 0.2s; }
  .nav-links a:hover { color: var(--teal); }
  .nav-cta { display: flex; align-items: center; gap: 12px; }
  .nav-phone { font-size: 0.88rem; color: var(--mid); font-weight: 500; }
  .btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 12px 24px; border-radius: 8px;
    font-family: 'Sora', sans-serif; font-weight: 600; font-size: 0.9rem;
    cursor: pointer; text-decoration: none; transition: all 0.2s; border: none;
  }
  .btn-primary { background: var(--teal); color: white; }
  .btn-primary:hover { background: #0c5e57; transform: translateY(-1px); box-shadow: 0 8px 24px rgba(15,118,110,0.28); }
  .btn-secondary { background: transparent; color: var(--dark); border: 1.5px solid var(--border); }
  .btn-secondary:hover { border-color: var(--teal); color: var(--teal); transform: translateY(-1px); }
  .btn-lg { padding: 15px 32px; font-size: 1rem; border-radius: 10px; }
  .hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 4px; }
  .hamburger span { display: block; width: 22px; height: 2px; background: var(--dark); border-radius: 2px; }
  section { padding: 80px 5%; }
  .section-inner { max-width: 1160px; margin: 0 auto; }
  .section-tag {
    display: inline-block; font-family: 'Sora', sans-serif;
    font-size: 0.72rem; font-weight: 700; text-transform: uppercase;
    letter-spacing: 0.1em; color: var(--teal); background: var(--teal-bg);
    padding: 5px 12px; border-radius: 100px; margin-bottom: 16px;
  }
  .section-title { font-size: clamp(1.8rem, 3.5vw, 2.6rem); font-weight: 800; color: var(--dark); margin-bottom: 16px; }
  .section-sub { font-size: 1.05rem; color: var(--soft); max-width: 560px; line-height: 1.7; font-weight: 300; }
  .section-header { margin-bottom: 48px; }
  footer { background: #0A0A0A; padding: 60px 5% 32px; }
  .footer-inner { max-width: 1160px; margin: 0 auto; }
  .footer-top {
    display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 48px; padding-bottom: 48px;
    border-bottom: 1px solid rgba(255,255,255,0.08); margin-bottom: 32px;
  }
  .footer-brand p { color: rgba(255,255,255,0.45); font-size: 0.88rem; line-height: 1.7; margin-top: 14px; font-weight: 300; max-width: 260px; }
  .footer-logo { display: flex; align-items: center; overflow: visible; max-height: none; }
  .footer-logo-img { height: 64px; width: auto; display: block; max-height: none; max-width: none; mix-blend-mode: screen; opacity: 0.95; }
  .footer-col-title { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: rgba(255,255,255,0.5); margin-bottom: 16px; }
  .footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }
  .footer-col a { color: rgba(255,255,255,0.7); text-decoration: none; font-size: 0.88rem; transition: color 0.2s; }
  .footer-col a:hover { color: var(--teal-light); }
  .footer-bottom { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 16px; }
  .footer-copy { color: rgba(255,255,255,0.3); font-size: 0.82rem; }
  .footer-phone { color: rgba(255,255,255,0.5); font-size: 0.88rem; }
  @media (max-width: 768px) {
    section { padding: 64px 5%; }
    .nav-links { display: none; }
    .hamburger { display: flex; }
    .footer-top { grid-template-columns: 1fr; gap: 32px; }
    .nav-logo-img { height: 36px; }
    .footer-logo-img { height: 52px; }
  }

.topic-hero {
    padding-top: 68px; background: var(--white);
    border-bottom: 1px solid var(--border);
  }
  .topic-hero-inner {
    max-width: 1160px; margin: 0 auto;
    padding: 64px 5% 56px;
    display: grid; grid-template-columns: 1fr 340px; gap: 64px; align-items: start;
  }
  .breadcrumb { display: flex; align-items: center; gap: 8px; font-size: 0.82rem; color: var(--soft); margin-bottom: 20px; }
  .breadcrumb a { color: var(--teal); text-decoration: none; font-weight: 500; }
  .breadcrumb a:hover { text-decoration: underline; }
  .breadcrumb-sep { color: var(--border); }
  .page-headline { font-size: clamp(2rem, 4vw, 3rem); font-weight: 800; color: var(--dark); margin-bottom: 16px; }
  .page-sub { font-size: 1.05rem; color: var(--mid); line-height: 1.7; font-weight: 300; max-width: 580px; }
  .topic-meta { display: flex; gap: 20px; margin-top: 24px; flex-wrap: wrap; }
  .meta-pill {
    display: flex; align-items: center; gap: 6px;
    background: var(--teal-bg); color: var(--teal);
    padding: 6px 14px; border-radius: 100px;
    font-size: 0.8rem; font-weight: 600; font-family: 'Sora', sans-serif;
  }
  .sidebar-card {
    background: var(--teal); color: white;
    border-radius: var(--radius); padding: 32px 28px;
    position: sticky; top: 88px;
  }
  .sidebar-card .sidebar-card-title { font-size: 1.1rem; font-weight: 800; margin-bottom: 8px; color: white; }
  .sidebar-card p { font-size: 0.9rem; opacity: 0.85; margin-bottom: 24px; font-weight: 300; line-height: 1.6; }
  .btn-white { background: white; color: var(--dark); }
  .btn-white:hover { background: #f5f5f5; transform: translateY(-1px); }
  .sidebar-card .btn { width: 100%; justify-content: center; }
  .sidebar-reassure { font-size: 0.78rem; opacity: 0.7; text-align: center; margin-top: 12px; }
  .content-body { max-width: 1160px; margin: 0 auto; padding: 0 5%; }
  .content-layout { display: grid; grid-template-columns: 1fr 340px; gap: 64px; align-items: start; padding: 64px 0; }
  .content-main h2 {
    font-size: 1.5rem; font-weight: 800; color: var(--dark);
    margin: 40px 0 16px; padding-top: 40px;
    border-top: 1px solid var(--border);
  }
  .content-main h2:first-child { margin-top: 0; padding-top: 0; border-top: none; }
  .content-main h3 { font-size: 1.1rem; font-weight: 700; color: var(--dark); margin: 28px 0 10px; }
  .content-main p { font-size: 0.97rem; color: var(--mid); line-height: 1.8; margin-bottom: 16px; font-weight: 300; }
  .content-main ul, .content-main ol {
    padding-left: 20px; margin-bottom: 16px;
  }
  .content-main li { font-size: 0.97rem; color: var(--mid); line-height: 1.8; font-weight: 300; margin-bottom: 6px; }
  .worked-example {
    background: var(--teal-bg); border: 1px solid rgba(20,184,166,0.2);
    border-radius: var(--radius); padding: 28px; margin: 24px 0;
  }
  .worked-example .ex-label {
    font-family: 'Sora', sans-serif; font-size: 0.72rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.1em; color: var(--teal);
    margin-bottom: 12px; display: block;
  }
  .worked-example .ex-question {
    font-family: 'Sora', sans-serif; font-size: 1.05rem; font-weight: 700;
    color: var(--dark); margin-bottom: 16px;
  }
  .worked-example .ex-step {
    display: flex; gap: 12px; margin-bottom: 10px; align-items: flex-start;
  }
  .worked-example .step-num {
    width: 24px; height: 24px; border-radius: 50%;
    background: var(--teal); color: white;
    font-family: 'Sora', sans-serif; font-size: 0.75rem; font-weight: 700;
    display: flex; align-items: center; justify-content: center; flex-shrink: 0;
    margin-top: 2px;
  }
  .worked-example .step-text { font-size: 0.95rem; color: var(--mid); line-height: 1.7; }
  .worked-example .step-text strong { color: var(--dark); font-weight: 600; }
  .answer-box {
    background: white; border: 1.5px solid var(--teal);
    border-radius: var(--radius-sm); padding: 12px 16px;
    margin-top: 16px; display: flex; align-items: center; gap: 10px;
  }
  .answer-box .ans-label {
    font-family: 'Sora', sans-serif; font-size: 0.75rem; font-weight: 700;
    color: var(--teal); text-transform: uppercase; letter-spacing: 0.06em; white-space: nowrap;
  }
  .answer-box .ans-value { font-size: 1rem; font-weight: 600; color: var(--dark); }
  .practice-questions { margin: 24px 0; }
  .pq-item {
    background: white; border: 1px solid var(--border);
    border-radius: var(--radius-sm); padding: 20px 24px;
    margin-bottom: 12px; display: flex; gap: 16px; align-items: flex-start;
  }
  .pq-num {
    font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700;
    color: var(--teal); min-width: 28px;
  }
  .pq-text { font-size: 0.95rem; color: var(--dark); line-height: 1.6; }
  .pq-diff {
    margin-left: auto; font-size: 0.72rem; font-weight: 700;
    font-family: 'Sora', sans-serif; padding: 3px 8px; border-radius: 100px;
    white-space: nowrap; align-self: center;
  }
  .diff-f { background: #DCFCE7; color: #166534; }
  .diff-h { background: #FEF9C3; color: #854D0E; }
  .diff-hh { background: #FEE2E2; color: #991B1B; }
  .answers-section {
    background: var(--bg-alt); border-radius: var(--radius);
    padding: 32px; margin-top: 32px;
  }
  .answers-section h3 { font-size: 1.1rem; font-weight: 700; margin-bottom: 20px; }
  .answer-row {
    display: flex; gap: 12px; padding: 10px 0;
    border-bottom: 1px solid var(--border); align-items: baseline;
  }
  .answer-row:last-child { border-bottom: none; }
  .ans-q { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; color: var(--teal); min-width: 28px; }
  .ans-a { font-size: 0.92rem; color: var(--dark); }
  .ans-note { font-size: 0.82rem; color: var(--soft); margin-left: 4px; }
  .toc {
    background: var(--bg-alt); border-radius: var(--radius);
    padding: 24px 28px; margin-bottom: 32px;
  }
  .toc-title { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--soft); margin-bottom: 14px; }
  .toc ul { list-style: none; display: flex; flex-direction: column; gap: 8px; }
  .toc a { color: var(--teal); text-decoration: none; font-size: 0.9rem; font-weight: 500; }
  .toc a:hover { text-decoration: underline; }
  .content-sidebar { position: sticky; top: 88px; display: flex; flex-direction: column; gap: 20px; }
  .cta-sidebar {
    background: var(--teal); color: white;
    border-radius: var(--radius); padding: 28px 24px;
  }
  .cta-sidebar .cta-sidebar-title { font-size: 1rem; font-weight: 800; margin-bottom: 8px; color: white; }
  .cta-sidebar p { font-size: 0.85rem; opacity: 0.85; margin-bottom: 20px; font-weight: 300; line-height: 1.6; }
  .cta-sidebar .btn { width: 100%; justify-content: center; }
  .cta-sidebar .sidebar-reassure { font-size: 0.75rem; opacity: 0.65; text-align: center; margin-top: 10px; }
  .next-topics { background: white; border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; }
  .next-topics-title { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--soft); margin-bottom: 14px; }
  .next-link {
    display: flex; align-items: center; gap: 10px; padding: 10px 0;
    border-bottom: 1px solid var(--border); text-decoration: none; color: var(--mid);
    font-size: 0.88rem; font-weight: 500; transition: color 0.2s;
  }
  .next-link:last-child { border-bottom: none; }
  .next-link:hover { color: var(--teal); }
  .next-link-icon { font-size: 1rem; }
  @media (max-width: 1024px) {
    .topic-hero-inner { grid-template-columns: 1fr; gap: 32px; }
    .content-layout { grid-template-columns: 1fr; gap: 32px; }
    .content-sidebar { position: static; }
    .sidebar-card { display: none; }
  }

.resources-hero {
    padding-top: 68px; background: var(--white);
    border-bottom: 1px solid var(--border);
  }
  .resources-hero-inner {
    max-width: 1160px; margin: 0 auto;
    padding: 64px 5% 56px;
  }
  .breadcrumb {
    display: flex; align-items: center; gap: 8px;
    font-size: 0.82rem; color: var(--soft); margin-bottom: 20px;
  }
  .breadcrumb a { color: var(--teal); text-decoration: none; font-weight: 500; }
  .breadcrumb a:hover { text-decoration: underline; }
  .breadcrumb-sep { color: var(--border); }
  .page-headline { font-size: clamp(2rem, 4vw, 3rem); font-weight: 800; color: var(--dark); margin-bottom: 16px; }
  .page-sub { font-size: 1.05rem; color: var(--mid); line-height: 1.7; font-weight: 300; max-width: 580px; }
  .topics-grid {
    display: grid; grid-template-columns: repeat(3, 1fr);
    gap: 20px;
  }
  .topic-card {
    background: white; border: 1px solid var(--border);
    border-radius: var(--radius); padding: 28px;
    text-decoration: none; color: inherit;
    transition: all 0.22s; display: block;
    position: relative; overflow: hidden;
  }
  .topic-card::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
    background: linear-gradient(90deg, var(--teal), var(--teal-light));
    transform: scaleX(0); transform-origin: left; transition: transform 0.3s;
  }
  .topic-card:hover { transform: translateY(-5px); box-shadow: 0 16px 40px rgba(0,0,0,0.07); }
  .topic-card:hover::before { transform: scaleX(1); }
  .topic-icon { font-size: 1.8rem; margin-bottom: 14px; display: block; }
  .topic-title { font-family: 'Sora', sans-serif; font-size: 1.05rem; font-weight: 700; color: var(--dark); margin-bottom: 8px; }
  .topic-desc { font-size: 0.88rem; color: var(--soft); line-height: 1.6; margin-bottom: 16px; }
  .topic-count { font-size: 0.78rem; color: var(--teal); font-weight: 600; font-family: 'Sora', sans-serif; }
  .topic-card.coming-soon { opacity: 0.55; cursor: default; pointer-events: none; }
  .coming-badge {
    position: absolute; top: 16px; right: 16px;
    background: var(--bg-alt); color: var(--soft);
    font-size: 0.68rem; font-weight: 700; font-family: 'Sora', sans-serif;
    padding: 3px 8px; border-radius: 100px; text-transform: uppercase;
    letter-spacing: 0.06em;
  }
  .resources-cta {
    background: var(--teal); border-radius: var(--radius);
    padding: 48px 40px; text-align: center; color: white; margin-top: 56px;
  }
  .resources-cta h2 { font-size: 1.6rem; font-weight: 800; margin-bottom: 10px; color: white; }
  .resources-cta p { font-size: 1rem; opacity: 0.85; margin-bottom: 28px; font-weight: 300; }
  .btn-white { background: white; color: var(--dark); }
  .btn-white:hover { background: #f5f5f5; transform: translateY(-1px); }
  @media (max-width: 768px) {
    .topics-grid { grid-template-columns: 1fr; }
    .resources-cta { padding: 32px 24px; }
  }
  @media (max-width: 1024px) {
    .topics-grid { grid-template-columns: repeat(2, 1fr); }
  }

/* ===== algebra-manipulation ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
  html { scroll-behavior: smooth; }
  body { font-family: 'DM Sans', sans-serif; color: var(--dark); background: var(--white); line-height: 1.6; -webkit-font-smoothing: antialiased; }
  h1,h2,h3,h4,h5 { font-family: 'Sora', sans-serif; line-height: 1.15; letter-spacing: -0.02em; }
  a { color: inherit; }
  nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    background: #ffffff; border-bottom: 1px solid var(--border);
    padding: 0 5%; height: 68px;
    display: flex; align-items: center; justify-content: space-between;
    transition: box-shadow 0.3s;
  }
  nav.scrolled { box-shadow: 0 2px 20px rgba(0,0,0,0.06); }
  .nav-logo { display: flex; align-items: center; text-decoration: none; flex-shrink: 0; }
  .nav-logo-img { height: 44px; width: auto; display: block; max-height: none; max-width: none; }
  .nav-links { display: flex; align-items: center; gap: 32px; list-style: none; }
  .nav-links a { text-decoration: none; color: var(--mid); font-size: 0.92rem; font-weight: 500; transition: color 0.2s; }
  .nav-links a:hover { color: var(--teal); }
  .nav-cta { display: flex; align-items: center; gap: 12px; }
  .nav-phone { font-size: 0.88rem; color: var(--mid); font-weight: 500; }
  .btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 12px 24px; border-radius: 8px;
    font-family: 'Sora', sans-serif; font-weight: 600; font-size: 0.9rem;
    cursor: pointer; text-decoration: none; transition: all 0.2s; border: none;
  }
  .btn-primary { background: var(--teal); color: white; }
  .btn-primary:hover { background: #0c5e57; transform: translateY(-1px); box-shadow: 0 8px 24px rgba(15,118,110,0.28); }
  .btn-secondary { background: transparent; color: var(--dark); border: 1.5px solid var(--border); }
  .btn-secondary:hover { border-color: var(--teal); color: var(--teal); transform: translateY(-1px); }
  .btn-lg { padding: 15px 32px; font-size: 1rem; border-radius: 10px; }
  .hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 4px; }
  .hamburger span { display: block; width: 22px; height: 2px; background: var(--dark); border-radius: 2px; }
  section { padding: 80px 5%; }
  .section-inner { max-width: 1160px; margin: 0 auto; }
  .section-tag {
    display: inline-block; font-family: 'Sora', sans-serif;
    font-size: 0.72rem; font-weight: 700; text-transform: uppercase;
    letter-spacing: 0.1em; color: var(--teal); background: var(--teal-bg);
    padding: 5px 12px; border-radius: 100px; margin-bottom: 16px;
  }
  .section-title { font-size: clamp(1.8rem, 3.5vw, 2.6rem); font-weight: 800; color: var(--dark); margin-bottom: 16px; }
  .section-sub { font-size: 1.05rem; color: var(--soft); max-width: 560px; line-height: 1.7; font-weight: 300; }
  .section-header { margin-bottom: 48px; }
  footer { background: #0A0A0A; padding: 60px 5% 32px; }
  .footer-inner { max-width: 1160px; margin: 0 auto; }
  .footer-top {
    display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 48px; padding-bottom: 48px;
    border-bottom: 1px solid rgba(255,255,255,0.08); margin-bottom: 32px;
  }
  .footer-brand p { color: rgba(255,255,255,0.45); font-size: 0.88rem; line-height: 1.7; margin-top: 14px; font-weight: 300; max-width: 260px; }
  .footer-logo { display: flex; align-items: center; overflow: visible; max-height: none; }
  .footer-logo-img { height: 64px; width: auto; display: block; max-height: none; max-width: none; mix-blend-mode: screen; opacity: 0.95; }
  .footer-col-title { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: rgba(255,255,255,0.5); margin-bottom: 16px; }
  .footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }
  .footer-col a { color: rgba(255,255,255,0.7); text-decoration: none; font-size: 0.88rem; transition: color 0.2s; }
  .footer-col a:hover { color: var(--teal-light); }
  .footer-bottom { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 16px; }
  .footer-copy { color: rgba(255,255,255,0.3); font-size: 0.82rem; }
  .footer-phone { color: rgba(255,255,255,0.5); font-size: 0.88rem; }
  @media (max-width: 768px) {
    section { padding: 64px 5%; }
    .nav-links { display: none; }
    .hamburger { display: flex; }
    .footer-top { grid-template-columns: 1fr; gap: 32px; }
    .nav-logo-img { height: 36px; }
    .footer-logo-img { height: 52px; }
  }

.topic-hero {
    padding-top: 68px; background: var(--white);
    border-bottom: 1px solid var(--border);
  }
  .topic-hero-inner {
    max-width: 1160px; margin: 0 auto;
    padding: 64px 5% 56px;
    display: grid; grid-template-columns: 1fr 340px; gap: 64px; align-items: start;
  }
  .breadcrumb { display: flex; align-items: center; gap: 8px; font-size: 0.82rem; color: var(--soft); margin-bottom: 20px; }
  .breadcrumb a { color: var(--teal); text-decoration: none; font-weight: 500; }
  .breadcrumb a:hover { text-decoration: underline; }
  .breadcrumb-sep { color: var(--border); }
  .page-headline { font-size: clamp(2rem, 4vw, 3rem); font-weight: 800; color: var(--dark); margin-bottom: 16px; }
  .page-sub { font-size: 1.05rem; color: var(--mid); line-height: 1.7; font-weight: 300; max-width: 580px; }
  .topic-meta { display: flex; gap: 20px; margin-top: 24px; flex-wrap: wrap; }
  .meta-pill {
    display: flex; align-items: center; gap: 6px;
    background: var(--teal-bg); color: var(--teal);
    padding: 6px 14px; border-radius: 100px;
    font-size: 0.8rem; font-weight: 600; font-family: 'Sora', sans-serif;
  }
  .sidebar-card {
    background: var(--teal); color: white;
    border-radius: var(--radius); padding: 32px 28px;
    position: sticky; top: 88px;
  }
  .sidebar-card .sidebar-card-title { font-size: 1.1rem; font-weight: 800; margin-bottom: 8px; color: white; }
  .sidebar-card p { font-size: 0.9rem; opacity: 0.85; margin-bottom: 24px; font-weight: 300; line-height: 1.6; }
  .btn-white { background: white; color: var(--dark); }
  .btn-white:hover { background: #f5f5f5; transform: translateY(-1px); }
  .sidebar-card .btn { width: 100%; justify-content: center; }
  .sidebar-reassure { font-size: 0.78rem; opacity: 0.7; text-align: center; margin-top: 12px; }
  .content-body { max-width: 1160px; margin: 0 auto; padding: 0 5%; }
  .content-layout { display: grid; grid-template-columns: 1fr 340px; gap: 64px; align-items: start; padding: 64px 0; }
  .content-main h2 {
    font-size: 1.5rem; font-weight: 800; color: var(--dark);
    margin: 40px 0 16px; padding-top: 40px;
    border-top: 1px solid var(--border);
  }
  .content-main h2:first-child { margin-top: 0; padding-top: 0; border-top: none; }
  .content-main h3 { font-size: 1.1rem; font-weight: 700; color: var(--dark); margin: 28px 0 10px; }
  .content-main p { font-size: 0.97rem; color: var(--mid); line-height: 1.8; margin-bottom: 16px; font-weight: 300; }
  .content-main ul, .content-main ol {
    padding-left: 20px; margin-bottom: 16px;
  }
  .content-main li { font-size: 0.97rem; color: var(--mid); line-height: 1.8; font-weight: 300; margin-bottom: 6px; }
  .worked-example {
    background: var(--teal-bg); border: 1px solid rgba(20,184,166,0.2);
    border-radius: var(--radius); padding: 28px; margin: 24px 0;
  }
  .worked-example .ex-label {
    font-family: 'Sora', sans-serif; font-size: 0.72rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.1em; color: var(--teal);
    margin-bottom: 12px; display: block;
  }
  .worked-example .ex-question {
    font-family: 'Sora', sans-serif; font-size: 1.05rem; font-weight: 700;
    color: var(--dark); margin-bottom: 16px;
  }
  .worked-example .ex-step {
    display: flex; gap: 12px; margin-bottom: 10px; align-items: flex-start;
  }
  .worked-example .step-num {
    width: 24px; height: 24px; border-radius: 50%;
    background: var(--teal); color: white;
    font-family: 'Sora', sans-serif; font-size: 0.75rem; font-weight: 700;
    display: flex; align-items: center; justify-content: center; flex-shrink: 0;
    margin-top: 2px;
  }
  .worked-example .step-text { font-size: 0.95rem; color: var(--mid); line-height: 1.7; }
  .worked-example .step-text strong { color: var(--dark); font-weight: 600; }
  .answer-box {
    background: white; border: 1.5px solid var(--teal);
    border-radius: var(--radius-sm); padding: 12px 16px;
    margin-top: 16px; display: flex; align-items: center; gap: 10px;
  }
  .answer-box .ans-label {
    font-family: 'Sora', sans-serif; font-size: 0.75rem; font-weight: 700;
    color: var(--teal); text-transform: uppercase; letter-spacing: 0.06em; white-space: nowrap;
  }
  .answer-box .ans-value { font-size: 1rem; font-weight: 600; color: var(--dark); }
  .practice-questions { margin: 24px 0; }
  .pq-item {
    background: white; border: 1px solid var(--border);
    border-radius: var(--radius-sm); padding: 20px 24px;
    margin-bottom: 12px; display: flex; gap: 16px; align-items: flex-start;
  }
  .pq-num {
    font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700;
    color: var(--teal); min-width: 28px;
  }
  .pq-text { font-size: 0.95rem; color: var(--dark); line-height: 1.6; }
  .pq-diff {
    margin-left: auto; font-size: 0.72rem; font-weight: 700;
    font-family: 'Sora', sans-serif; padding: 3px 8px; border-radius: 100px;
    white-space: nowrap; align-self: center;
  }
  .diff-f { background: #DCFCE7; color: #166534; }
  .diff-h { background: #FEF9C3; color: #854D0E; }
  .diff-hh { background: #FEE2E2; color: #991B1B; }
  .answers-section {
    background: var(--bg-alt); border-radius: var(--radius);
    padding: 32px; margin-top: 32px;
  }
  .answers-section h3 { font-size: 1.1rem; font-weight: 700; margin-bottom: 20px; }
  .answer-row {
    display: flex; gap: 12px; padding: 10px 0;
    border-bottom: 1px solid var(--border); align-items: baseline;
  }
  .answer-row:last-child { border-bottom: none; }
  .ans-q { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; color: var(--teal); min-width: 28px; }
  .ans-a { font-size: 0.92rem; color: var(--dark); }
  .ans-note { font-size: 0.82rem; color: var(--soft); margin-left: 4px; }
  .toc {
    background: var(--bg-alt); border-radius: var(--radius);
    padding: 24px 28px; margin-bottom: 32px;
  }
  .toc-title { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--soft); margin-bottom: 14px; }
  .toc ul { list-style: none; display: flex; flex-direction: column; gap: 8px; }
  .toc a { color: var(--teal); text-decoration: none; font-size: 0.9rem; font-weight: 500; }
  .toc a:hover { text-decoration: underline; }
  .content-sidebar { position: sticky; top: 88px; display: flex; flex-direction: column; gap: 20px; }
  .cta-sidebar {
    background: var(--teal); color: white;
    border-radius: var(--radius); padding: 28px 24px;
  }
  .cta-sidebar .cta-sidebar-title { font-size: 1rem; font-weight: 800; margin-bottom: 8px; color: white; }
  .cta-sidebar p { font-size: 0.85rem; opacity: 0.85; margin-bottom: 20px; font-weight: 300; line-height: 1.6; }
  .cta-sidebar .btn { width: 100%; justify-content: center; }
  .cta-sidebar .sidebar-reassure { font-size: 0.75rem; opacity: 0.65; text-align: center; margin-top: 10px; }
  .next-topics { background: white; border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; }
  .next-topics-title { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--soft); margin-bottom: 14px; }
  .next-link {
    display: flex; align-items: center; gap: 10px; padding: 10px 0;
    border-bottom: 1px solid var(--border); text-decoration: none; color: var(--mid);
    font-size: 0.88rem; font-weight: 500; transition: color 0.2s;
  }
  .next-link:last-child { border-bottom: none; }
  .next-link:hover { color: var(--teal); }
  .next-link-icon { font-size: 1rem; }
  @media (max-width: 1024px) {
    .topic-hero-inner { grid-template-columns: 1fr; gap: 32px; }
    .content-layout { grid-template-columns: 1fr; gap: 32px; }
    .content-sidebar { position: static; }
    .sidebar-card { display: none; }
  }

.mistakes-section { margin-top: 40px; }
  .mistake-item {
    background: white; border: 1px solid var(--border);
    border-left: 4px solid #EF4444;
    border-radius: var(--radius-sm); padding: 20px 24px;
    margin-bottom: 14px;
  }
  .mistake-label {
    font-family: 'Sora', sans-serif; font-size: 0.72rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.1em; color: #EF4444;
    margin-bottom: 8px; display: block;
  }
  .mistake-title { font-family: 'Sora', sans-serif; font-size: 0.97rem; font-weight: 700; color: var(--dark); margin-bottom: 6px; }
  .mistake-text { font-size: 0.92rem; color: var(--mid); line-height: 1.7; }
  .mistake-text strong { color: var(--dark); }
  .answers-group { margin-bottom: 28px; }
  .answers-group h4 {
    font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.08em; color: var(--soft);
    margin-bottom: 14px; border-bottom: 1px solid var(--border); padding-bottom: 8px;
  }

.subtopic-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 20px;
    margin: 24px 0 40px;
  }
  .subtopic-card {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    text-decoration: none;
    color: var(--dark);
    display: flex;
    flex-direction: column;
    gap: 8px;
    transition: transform 0.2s, box-shadow 0.2s;
    position: relative;
    overflow: hidden;
  }
  .subtopic-card::before {
    content: '';
    position: absolute;
    bottom: 0; left: 0; right: 0;
    height: 3px;
    background: var(--teal);
    transform: scaleX(0);
    transition: transform 0.2s;
  }
  .subtopic-card:hover { transform: translateY(-4px); box-shadow: 0 12px 32px rgba(0,0,0,0.07); }
  .subtopic-card:hover::before { transform: scaleX(1); }
  .subtopic-icon { font-size: 1.6rem; margin-bottom: 4px; }
  .subtopic-title { font-family: 'Sora', sans-serif; font-size: 1rem; font-weight: 700; color: var(--dark); }
  .subtopic-desc { font-size: 0.88rem; color: var(--soft); line-height: 1.6; flex: 1; }
  .subtopic-cta {
    font-family: 'Sora', sans-serif; font-size: 0.78rem; font-weight: 700;
    color: var(--teal); text-transform: uppercase; letter-spacing: 0.06em; margin-top: 8px;
  }

/* ===== algebra-graphs-equations ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
  html { scroll-behavior: smooth; }
  body { font-family: 'DM Sans', sans-serif; color: var(--dark); background: var(--white); line-height: 1.6; -webkit-font-smoothing: antialiased; }
  h1,h2,h3,h4,h5 { font-family: 'Sora', sans-serif; line-height: 1.15; letter-spacing: -0.02em; }
  a { color: inherit; }
  nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    background: #ffffff; border-bottom: 1px solid var(--border);
    padding: 0 5%; height: 68px;
    display: flex; align-items: center; justify-content: space-between;
    transition: box-shadow 0.3s;
  }
  nav.scrolled { box-shadow: 0 2px 20px rgba(0,0,0,0.06); }
  .nav-logo { display: flex; align-items: center; text-decoration: none; flex-shrink: 0; }
  .nav-logo-img { height: 44px; width: auto; display: block; max-height: none; max-width: none; }
  .nav-links { display: flex; align-items: center; gap: 32px; list-style: none; }
  .nav-links a { text-decoration: none; color: var(--mid); font-size: 0.92rem; font-weight: 500; transition: color 0.2s; }
  .nav-links a:hover { color: var(--teal); }
  .nav-cta { display: flex; align-items: center; gap: 12px; }
  .nav-phone { font-size: 0.88rem; color: var(--mid); font-weight: 500; }
  .btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 12px 24px; border-radius: 8px;
    font-family: 'Sora', sans-serif; font-weight: 600; font-size: 0.9rem;
    cursor: pointer; text-decoration: none; transition: all 0.2s; border: none;
  }
  .btn-primary { background: var(--teal); color: white; }
  .btn-primary:hover { background: #0c5e57; transform: translateY(-1px); box-shadow: 0 8px 24px rgba(15,118,110,0.28); }
  .btn-secondary { background: transparent; color: var(--dark); border: 1.5px solid var(--border); }
  .btn-secondary:hover { border-color: var(--teal); color: var(--teal); transform: translateY(-1px); }
  .btn-lg { padding: 15px 32px; font-size: 1rem; border-radius: 10px; }
  .hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 4px; }
  .hamburger span { display: block; width: 22px; height: 2px; background: var(--dark); border-radius: 2px; }
  section { padding: 80px 5%; }
  .section-inner { max-width: 1160px; margin: 0 auto; }
  .section-tag {
    display: inline-block; font-family: 'Sora', sans-serif;
    font-size: 0.72rem; font-weight: 700; text-transform: uppercase;
    letter-spacing: 0.1em; color: var(--teal); background: var(--teal-bg);
    padding: 5px 12px; border-radius: 100px; margin-bottom: 16px;
  }
  .section-title { font-size: clamp(1.8rem, 3.5vw, 2.6rem); font-weight: 800; color: var(--dark); margin-bottom: 16px; }
  .section-sub { font-size: 1.05rem; color: var(--soft); max-width: 560px; line-height: 1.7; font-weight: 300; }
  .section-header { margin-bottom: 48px; }
  footer { background: #0A0A0A; padding: 60px 5% 32px; }
  .footer-inner { max-width: 1160px; margin: 0 auto; }
  .footer-top {
    display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 48px; padding-bottom: 48px;
    border-bottom: 1px solid rgba(255,255,255,0.08); margin-bottom: 32px;
  }
  .footer-brand p { color: rgba(255,255,255,0.45); font-size: 0.88rem; line-height: 1.7; margin-top: 14px; font-weight: 300; max-width: 260px; }
  .footer-logo { display: flex; align-items: center; overflow: visible; max-height: none; }
  .footer-logo-img { height: 64px; width: auto; display: block; max-height: none; max-width: none; mix-blend-mode: screen; opacity: 0.95; }
  .footer-col-title { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: rgba(255,255,255,0.5); margin-bottom: 16px; }
  .footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }
  .footer-col a { color: rgba(255,255,255,0.7); text-decoration: none; font-size: 0.88rem; transition: color 0.2s; }
  .footer-col a:hover { color: var(--teal-light); }
  .footer-bottom { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 16px; }
  .footer-copy { color: rgba(255,255,255,0.3); font-size: 0.82rem; }
  .footer-phone { color: rgba(255,255,255,0.5); font-size: 0.88rem; }
  @media (max-width: 768px) {
    section { padding: 64px 5%; }
    .nav-links { display: none; }
    .hamburger { display: flex; }
    .footer-top { grid-template-columns: 1fr; gap: 32px; }
    .nav-logo-img { height: 36px; }
    .footer-logo-img { height: 52px; }
  }

.topic-hero {
    padding-top: 68px; background: var(--white);
    border-bottom: 1px solid var(--border);
  }
  .topic-hero-inner {
    max-width: 1160px; margin: 0 auto;
    padding: 64px 5% 56px;
    display: grid; grid-template-columns: 1fr 340px; gap: 64px; align-items: start;
  }
  .breadcrumb { display: flex; align-items: center; gap: 8px; font-size: 0.82rem; color: var(--soft); margin-bottom: 20px; }
  .breadcrumb a { color: var(--teal); text-decoration: none; font-weight: 500; }
  .breadcrumb a:hover { text-decoration: underline; }
  .breadcrumb-sep { color: var(--border); }
  .page-headline { font-size: clamp(2rem, 4vw, 3rem); font-weight: 800; color: var(--dark); margin-bottom: 16px; }
  .page-sub { font-size: 1.05rem; color: var(--mid); line-height: 1.7; font-weight: 300; max-width: 580px; }
  .topic-meta { display: flex; gap: 20px; margin-top: 24px; flex-wrap: wrap; }
  .meta-pill {
    display: flex; align-items: center; gap: 6px;
    background: var(--teal-bg); color: var(--teal);
    padding: 6px 14px; border-radius: 100px;
    font-size: 0.8rem; font-weight: 600; font-family: 'Sora', sans-serif;
  }
  .sidebar-card {
    background: var(--teal); color: white;
    border-radius: var(--radius); padding: 32px 28px;
    position: sticky; top: 88px;
  }
  .sidebar-card .sidebar-card-title { font-size: 1.1rem; font-weight: 800; margin-bottom: 8px; color: white; }
  .sidebar-card p { font-size: 0.9rem; opacity: 0.85; margin-bottom: 24px; font-weight: 300; line-height: 1.6; }
  .btn-white { background: white; color: var(--dark); }
  .btn-white:hover { background: #f5f5f5; transform: translateY(-1px); }
  .sidebar-card .btn { width: 100%; justify-content: center; }
  .sidebar-reassure { font-size: 0.78rem; opacity: 0.7; text-align: center; margin-top: 12px; }
  .content-body { max-width: 1160px; margin: 0 auto; padding: 0 5%; }
  .content-layout { display: grid; grid-template-columns: 1fr 340px; gap: 64px; align-items: start; padding: 64px 0; }
  .content-main h2 {
    font-size: 1.5rem; font-weight: 800; color: var(--dark);
    margin: 40px 0 16px; padding-top: 40px;
    border-top: 1px solid var(--border);
  }
  .content-main h2:first-child { margin-top: 0; padding-top: 0; border-top: none; }
  .content-main h3 { font-size: 1.1rem; font-weight: 700; color: var(--dark); margin: 28px 0 10px; }
  .content-main p { font-size: 0.97rem; color: var(--mid); line-height: 1.8; margin-bottom: 16px; font-weight: 300; }
  .content-main ul, .content-main ol {
    padding-left: 20px; margin-bottom: 16px;
  }
  .content-main li { font-size: 0.97rem; color: var(--mid); line-height: 1.8; font-weight: 300; margin-bottom: 6px; }
  .worked-example {
    background: var(--teal-bg); border: 1px solid rgba(20,184,166,0.2);
    border-radius: var(--radius); padding: 28px; margin: 24px 0;
  }
  .worked-example .ex-label {
    font-family: 'Sora', sans-serif; font-size: 0.72rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.1em; color: var(--teal);
    margin-bottom: 12px; display: block;
  }
  .worked-example .ex-question {
    font-family: 'Sora', sans-serif; font-size: 1.05rem; font-weight: 700;
    color: var(--dark); margin-bottom: 16px;
  }
  .worked-example .ex-step {
    display: flex; gap: 12px; margin-bottom: 10px; align-items: flex-start;
  }
  .worked-example .step-num {
    width: 24px; height: 24px; border-radius: 50%;
    background: var(--teal); color: white;
    font-family: 'Sora', sans-serif; font-size: 0.75rem; font-weight: 700;
    display: flex; align-items: center; justify-content: center; flex-shrink: 0;
    margin-top: 2px;
  }
  .worked-example .step-text { font-size: 0.95rem; color: var(--mid); line-height: 1.7; }
  .worked-example .step-text strong { color: var(--dark); font-weight: 600; }
  .answer-box {
    background: white; border: 1.5px solid var(--teal);
    border-radius: var(--radius-sm); padding: 12px 16px;
    margin-top: 16px; display: flex; align-items: center; gap: 10px;
  }
  .answer-box .ans-label {
    font-family: 'Sora', sans-serif; font-size: 0.75rem; font-weight: 700;
    color: var(--teal); text-transform: uppercase; letter-spacing: 0.06em; white-space: nowrap;
  }
  .answer-box .ans-value { font-size: 1rem; font-weight: 600; color: var(--dark); }
  .practice-questions { margin: 24px 0; }
  .pq-item {
    background: white; border: 1px solid var(--border);
    border-radius: var(--radius-sm); padding: 20px 24px;
    margin-bottom: 12px; display: flex; gap: 16px; align-items: flex-start;
  }
  .pq-num {
    font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700;
    color: var(--teal); min-width: 28px;
  }
  .pq-text { font-size: 0.95rem; color: var(--dark); line-height: 1.6; }
  .pq-diff {
    margin-left: auto; font-size: 0.72rem; font-weight: 700;
    font-family: 'Sora', sans-serif; padding: 3px 8px; border-radius: 100px;
    white-space: nowrap; align-self: center;
  }
  .diff-f { background: #DCFCE7; color: #166534; }
  .diff-h { background: #FEF9C3; color: #854D0E; }
  .diff-hh { background: #FEE2E2; color: #991B1B; }
  .answers-section {
    background: var(--bg-alt); border-radius: var(--radius);
    padding: 32px; margin-top: 32px;
  }
  .answers-section h3 { font-size: 1.1rem; font-weight: 700; margin-bottom: 20px; }
  .answer-row {
    display: flex; gap: 12px; padding: 10px 0;
    border-bottom: 1px solid var(--border); align-items: baseline;
  }
  .answer-row:last-child { border-bottom: none; }
  .ans-q { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; color: var(--teal); min-width: 28px; }
  .ans-a { font-size: 0.92rem; color: var(--dark); }
  .ans-note { font-size: 0.82rem; color: var(--soft); margin-left: 4px; }
  .toc {
    background: var(--bg-alt); border-radius: var(--radius);
    padding: 24px 28px; margin-bottom: 32px;
  }
  .toc-title { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--soft); margin-bottom: 14px; }
  .toc ul { list-style: none; display: flex; flex-direction: column; gap: 8px; }
  .toc a { color: var(--teal); text-decoration: none; font-size: 0.9rem; font-weight: 500; }
  .toc a:hover { text-decoration: underline; }
  .content-sidebar { position: sticky; top: 88px; display: flex; flex-direction: column; gap: 20px; }
  .cta-sidebar {
    background: var(--teal); color: white;
    border-radius: var(--radius); padding: 28px 24px;
  }
  .cta-sidebar .cta-sidebar-title { font-size: 1rem; font-weight: 800; margin-bottom: 8px; color: white; }
  .cta-sidebar p { font-size: 0.85rem; opacity: 0.85; margin-bottom: 20px; font-weight: 300; line-height: 1.6; }
  .cta-sidebar .btn { width: 100%; justify-content: center; }
  .cta-sidebar .sidebar-reassure { font-size: 0.75rem; opacity: 0.65; text-align: center; margin-top: 10px; }
  .next-topics { background: white; border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; }
  .next-topics-title { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--soft); margin-bottom: 14px; }
  .next-link {
    display: flex; align-items: center; gap: 10px; padding: 10px 0;
    border-bottom: 1px solid var(--border); text-decoration: none; color: var(--mid);
    font-size: 0.88rem; font-weight: 500; transition: color 0.2s;
  }
  .next-link:last-child { border-bottom: none; }
  .next-link:hover { color: var(--teal); }
  .next-link-icon { font-size: 1rem; }
  @media (max-width: 1024px) {
    .topic-hero-inner { grid-template-columns: 1fr; gap: 32px; }
    .content-layout { grid-template-columns: 1fr; gap: 32px; }
    .content-sidebar { position: static; }
    .sidebar-card { display: none; }
  }

.mistakes-section { margin-top: 40px; }
  .mistake-item {
    background: white; border: 1px solid var(--border);
    border-left: 4px solid #EF4444;
    border-radius: var(--radius-sm); padding: 20px 24px;
    margin-bottom: 14px;
  }
  .mistake-label {
    font-family: 'Sora', sans-serif; font-size: 0.72rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.1em; color: #EF4444;
    margin-bottom: 8px; display: block;
  }
  .mistake-title { font-family: 'Sora', sans-serif; font-size: 0.97rem; font-weight: 700; color: var(--dark); margin-bottom: 6px; }
  .mistake-text { font-size: 0.92rem; color: var(--mid); line-height: 1.7; }
  .mistake-text strong { color: var(--dark); }
  .answers-group { margin-bottom: 28px; }
  .answers-group h4 {
    font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.08em; color: var(--soft);
    margin-bottom: 14px; border-bottom: 1px solid var(--border); padding-bottom: 8px;
  }

/* ===== statistics-hub ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
  html { scroll-behavior: smooth; }
  body { font-family: 'DM Sans', sans-serif; color: var(--dark); background: var(--white); line-height: 1.6; -webkit-font-smoothing: antialiased; }
  h1,h2,h3,h4,h5 { font-family: 'Sora', sans-serif; line-height: 1.15; letter-spacing: -0.02em; }
  a { color: inherit; }
  nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    background: #ffffff; border-bottom: 1px solid var(--border);
    padding: 0 5%; height: 68px;
    display: flex; align-items: center; justify-content: space-between;
    transition: box-shadow 0.3s;
  }
  nav.scrolled { box-shadow: 0 2px 20px rgba(0,0,0,0.06); }
  .nav-logo { display: flex; align-items: center; text-decoration: none; flex-shrink: 0; }
  .nav-logo-img { height: 44px; width: auto; display: block; max-height: none; max-width: none; }
  .nav-links { display: flex; align-items: center; gap: 32px; list-style: none; }
  .nav-links a { text-decoration: none; color: var(--mid); font-size: 0.92rem; font-weight: 500; transition: color 0.2s; }
  .nav-links a:hover { color: var(--teal); }
  .nav-cta { display: flex; align-items: center; gap: 12px; }
  .nav-phone { font-size: 0.88rem; color: var(--mid); font-weight: 500; }
  .btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 12px 24px; border-radius: 8px;
    font-family: 'Sora', sans-serif; font-weight: 600; font-size: 0.9rem;
    cursor: pointer; text-decoration: none; transition: all 0.2s; border: none;
  }
  .btn-primary { background: var(--teal); color: white; }
  .btn-primary:hover { background: #0c5e57; transform: translateY(-1px); box-shadow: 0 8px 24px rgba(15,118,110,0.28); }
  .btn-secondary { background: transparent; color: var(--dark); border: 1.5px solid var(--border); }
  .btn-secondary:hover { border-color: var(--teal); color: var(--teal); transform: translateY(-1px); }
  .btn-lg { padding: 15px 32px; font-size: 1rem; border-radius: 10px; }
  .hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 4px; }
  .hamburger span { display: block; width: 22px; height: 2px; background: var(--dark); border-radius: 2px; }
  section { padding: 80px 5%; }
  .section-inner { max-width: 1160px; margin: 0 auto; }
  .section-tag {
    display: inline-block; font-family: 'Sora', sans-serif;
    font-size: 0.72rem; font-weight: 700; text-transform: uppercase;
    letter-spacing: 0.1em; color: var(--teal); background: var(--teal-bg);
    padding: 5px 12px; border-radius: 100px; margin-bottom: 16px;
  }
  .section-title { font-size: clamp(1.8rem, 3.5vw, 2.6rem); font-weight: 800; color: var(--dark); margin-bottom: 16px; }
  .section-sub { font-size: 1.05rem; color: var(--soft); max-width: 560px; line-height: 1.7; font-weight: 300; }
  .section-header { margin-bottom: 48px; }
  footer { background: #0A0A0A; padding: 60px 5% 32px; }
  .footer-inner { max-width: 1160px; margin: 0 auto; }
  .footer-top {
    display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 48px; padding-bottom: 48px;
    border-bottom: 1px solid rgba(255,255,255,0.08); margin-bottom: 32px;
  }
  .footer-brand p { color: rgba(255,255,255,0.45); font-size: 0.88rem; line-height: 1.7; margin-top: 14px; font-weight: 300; max-width: 260px; }
  .footer-logo { display: flex; align-items: center; overflow: visible; max-height: none; }
  .footer-logo-img { height: 64px; width: auto; display: block; max-height: none; max-width: none; mix-blend-mode: screen; opacity: 0.95; }
  .footer-col-title { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: rgba(255,255,255,0.5); margin-bottom: 16px; }
  .footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }
  .footer-col a { color: rgba(255,255,255,0.7); text-decoration: none; font-size: 0.88rem; transition: color 0.2s; }
  .footer-col a:hover { color: var(--teal-light); }
  .footer-bottom { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 16px; }
  .footer-copy { color: rgba(255,255,255,0.3); font-size: 0.82rem; }
  .footer-phone { color: rgba(255,255,255,0.5); font-size: 0.88rem; }
  @media (max-width: 768px) {
    section { padding: 64px 5%; }
    .nav-links { display: none; }
    .hamburger { display: flex; }
    .footer-top { grid-template-columns: 1fr; gap: 32px; }
    .nav-logo-img { height: 36px; }
    .footer-logo-img { height: 52px; }
  }

.topic-hero {
    padding-top: 68px; background: var(--white);
    border-bottom: 1px solid var(--border);
  }
  .topic-hero-inner {
    max-width: 1160px; margin: 0 auto;
    padding: 64px 5% 56px;
    display: grid; grid-template-columns: 1fr 340px; gap: 64px; align-items: start;
  }
  .breadcrumb { display: flex; align-items: center; gap: 8px; font-size: 0.82rem; color: var(--soft); margin-bottom: 20px; }
  .breadcrumb a { color: var(--teal); text-decoration: none; font-weight: 500; }
  .breadcrumb a:hover { text-decoration: underline; }
  .breadcrumb-sep { color: var(--border); }
  .page-headline { font-size: clamp(2rem, 4vw, 3rem); font-weight: 800; color: var(--dark); margin-bottom: 16px; }
  .page-sub { font-size: 1.05rem; color: var(--mid); line-height: 1.7; font-weight: 300; max-width: 580px; }
  .topic-meta { display: flex; gap: 20px; margin-top: 24px; flex-wrap: wrap; }
  .meta-pill {
    display: flex; align-items: center; gap: 6px;
    background: var(--teal-bg); color: var(--teal);
    padding: 6px 14px; border-radius: 100px;
    font-size: 0.8rem; font-weight: 600; font-family: 'Sora', sans-serif;
  }
  .sidebar-card {
    background: var(--teal); color: white;
    border-radius: var(--radius); padding: 32px 28px;
    position: sticky; top: 88px;
  }
  .sidebar-card .sidebar-card-title { font-size: 1.1rem; font-weight: 800; margin-bottom: 8px; color: white; }
  .sidebar-card p { font-size: 0.9rem; opacity: 0.85; margin-bottom: 24px; font-weight: 300; line-height: 1.6; }
  .btn-white { background: white; color: var(--dark); }
  .btn-white:hover { background: #f5f5f5; transform: translateY(-1px); }
  .sidebar-card .btn { width: 100%; justify-content: center; }
  .sidebar-reassure { font-size: 0.78rem; opacity: 0.7; text-align: center; margin-top: 12px; }
  .content-body { max-width: 1160px; margin: 0 auto; padding: 0 5%; }
  .content-layout { display: grid; grid-template-columns: 1fr 340px; gap: 64px; align-items: start; padding: 64px 0; }
  .content-main h2 {
    font-size: 1.5rem; font-weight: 800; color: var(--dark);
    margin: 40px 0 16px; padding-top: 40px;
    border-top: 1px solid var(--border);
  }
  .content-main h2:first-child { margin-top: 0; padding-top: 0; border-top: none; }
  .content-main h3 { font-size: 1.1rem; font-weight: 700; color: var(--dark); margin: 28px 0 10px; }
  .content-main p { font-size: 0.97rem; color: var(--mid); line-height: 1.8; margin-bottom: 16px; font-weight: 300; }
  .content-main ul, .content-main ol {
    padding-left: 20px; margin-bottom: 16px;
  }
  .content-main li { font-size: 0.97rem; color: var(--mid); line-height: 1.8; font-weight: 300; margin-bottom: 6px; }
  .worked-example {
    background: var(--teal-bg); border: 1px solid rgba(20,184,166,0.2);
    border-radius: var(--radius); padding: 28px; margin: 24px 0;
  }
  .worked-example .ex-label {
    font-family: 'Sora', sans-serif; font-size: 0.72rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.1em; color: var(--teal);
    margin-bottom: 12px; display: block;
  }
  .worked-example .ex-question {
    font-family: 'Sora', sans-serif; font-size: 1.05rem; font-weight: 700;
    color: var(--dark); margin-bottom: 16px;
  }
  .worked-example .ex-step {
    display: flex; gap: 12px; margin-bottom: 10px; align-items: flex-start;
  }
  .worked-example .step-num {
    width: 24px; height: 24px; border-radius: 50%;
    background: var(--teal); color: white;
    font-family: 'Sora', sans-serif; font-size: 0.75rem; font-weight: 700;
    display: flex; align-items: center; justify-content: center; flex-shrink: 0;
    margin-top: 2px;
  }
  .worked-example .step-text { font-size: 0.95rem; color: var(--mid); line-height: 1.7; }
  .worked-example .step-text strong { color: var(--dark); font-weight: 600; }
  .answer-box {
    background: white; border: 1.5px solid var(--teal);
    border-radius: var(--radius-sm); padding: 12px 16px;
    margin-top: 16px; display: flex; align-items: center; gap: 10px;
  }
  .answer-box .ans-label {
    font-family: 'Sora', sans-serif; font-size: 0.75rem; font-weight: 700;
    color: var(--teal); text-transform: uppercase; letter-spacing: 0.06em; white-space: nowrap;
  }
  .answer-box .ans-value { font-size: 1rem; font-weight: 600; color: var(--dark); }
  .practice-questions { margin: 24px 0; }
  .pq-item {
    background: white; border: 1px solid var(--border);
    border-radius: var(--radius-sm); padding: 20px 24px;
    margin-bottom: 12px; display: flex; gap: 16px; align-items: flex-start;
  }
  .pq-num {
    font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700;
    color: var(--teal); min-width: 28px;
  }
  .pq-text { font-size: 0.95rem; color: var(--dark); line-height: 1.6; }
  .pq-diff {
    margin-left: auto; font-size: 0.72rem; font-weight: 700;
    font-family: 'Sora', sans-serif; padding: 3px 8px; border-radius: 100px;
    white-space: nowrap; align-self: center;
  }
  .diff-f { background: #DCFCE7; color: #166534; }
  .diff-h { background: #FEF9C3; color: #854D0E; }
  .diff-hh { background: #FEE2E2; color: #991B1B; }
  .answers-section {
    background: var(--bg-alt); border-radius: var(--radius);
    padding: 32px; margin-top: 32px;
  }
  .answers-section h3 { font-size: 1.1rem; font-weight: 700; margin-bottom: 20px; }
  .answer-row {
    display: flex; gap: 12px; padding: 10px 0;
    border-bottom: 1px solid var(--border); align-items: baseline;
  }
  .answer-row:last-child { border-bottom: none; }
  .ans-q { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; color: var(--teal); min-width: 28px; }
  .ans-a { font-size: 0.92rem; color: var(--dark); }
  .ans-note { font-size: 0.82rem; color: var(--soft); margin-left: 4px; }
  .toc {
    background: var(--bg-alt); border-radius: var(--radius);
    padding: 24px 28px; margin-bottom: 32px;
  }
  .toc-title { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--soft); margin-bottom: 14px; }
  .toc ul { list-style: none; display: flex; flex-direction: column; gap: 8px; }
  .toc a { color: var(--teal); text-decoration: none; font-size: 0.9rem; font-weight: 500; }
  .toc a:hover { text-decoration: underline; }
  .content-sidebar { position: sticky; top: 88px; display: flex; flex-direction: column; gap: 20px; }
  .cta-sidebar {
    background: var(--teal); color: white;
    border-radius: var(--radius); padding: 28px 24px;
  }
  .cta-sidebar .cta-sidebar-title { font-size: 1rem; font-weight: 800; margin-bottom: 8px; color: white; }
  .cta-sidebar p { font-size: 0.85rem; opacity: 0.85; margin-bottom: 20px; font-weight: 300; line-height: 1.6; }
  .cta-sidebar .btn { width: 100%; justify-content: center; }
  .cta-sidebar .sidebar-reassure { font-size: 0.75rem; opacity: 0.65; text-align: center; margin-top: 10px; }
  .next-topics { background: white; border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; }
  .next-topics-title { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--soft); margin-bottom: 14px; }
  .next-link {
    display: flex; align-items: center; gap: 10px; padding: 10px 0;
    border-bottom: 1px solid var(--border); text-decoration: none; color: var(--mid);
    font-size: 0.88rem; font-weight: 500; transition: color 0.2s;
  }
  .next-link:last-child { border-bottom: none; }
  .next-link:hover { color: var(--teal); }
  .next-link-icon { font-size: 1rem; }
  @media (max-width: 1024px) {
    .topic-hero-inner { grid-template-columns: 1fr; gap: 32px; }
    .content-layout { grid-template-columns: 1fr; gap: 32px; }
    .content-sidebar { position: static; }
    .sidebar-card { display: none; }
  }

.resources-hero {
    padding-top: 68px; background: var(--white);
    border-bottom: 1px solid var(--border);
  }
  .resources-hero-inner {
    max-width: 1160px; margin: 0 auto;
    padding: 64px 5% 56px;
  }
  .breadcrumb {
    display: flex; align-items: center; gap: 8px;
    font-size: 0.82rem; color: var(--soft); margin-bottom: 20px;
  }
  .breadcrumb a { color: var(--teal); text-decoration: none; font-weight: 500; }
  .breadcrumb a:hover { text-decoration: underline; }
  .breadcrumb-sep { color: var(--border); }
  .page-headline { font-size: clamp(2rem, 4vw, 3rem); font-weight: 800; color: var(--dark); margin-bottom: 16px; }
  .page-sub { font-size: 1.05rem; color: var(--mid); line-height: 1.7; font-weight: 300; max-width: 580px; }
  .topics-grid {
    display: grid; grid-template-columns: repeat(3, 1fr);
    gap: 20px;
  }
  .topic-card {
    background: white; border: 1px solid var(--border);
    border-radius: var(--radius); padding: 28px;
    text-decoration: none; color: inherit;
    transition: all 0.22s; display: block;
    position: relative; overflow: hidden;
  }
  .topic-card::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
    background: linear-gradient(90deg, var(--teal), var(--teal-light));
    transform: scaleX(0); transform-origin: left; transition: transform 0.3s;
  }
  .topic-card:hover { transform: translateY(-5px); box-shadow: 0 16px 40px rgba(0,0,0,0.07); }
  .topic-card:hover::before { transform: scaleX(1); }
  .topic-icon { margin-bottom: 14px; display: block; line-height: 1; }
  .topic-title { font-family: 'Sora', sans-serif; font-size: 1.05rem; font-weight: 700; color: var(--dark); margin-bottom: 8px; }
  .topic-desc { font-size: 0.88rem; color: var(--soft); line-height: 1.6; margin-bottom: 16px; }
  .topic-count { font-size: 0.78rem; color: var(--teal); font-weight: 600; font-family: 'Sora', sans-serif; }
  .topic-card.coming-soon { opacity: 0.55; cursor: default; pointer-events: none; }
  .coming-badge {
    position: absolute; top: 16px; right: 16px;
    background: var(--bg-alt); color: var(--soft);
    font-size: 0.68rem; font-weight: 700; font-family: 'Sora', sans-serif;
    padding: 3px 8px; border-radius: 100px; text-transform: uppercase;
    letter-spacing: 0.06em;
  }
  .resources-cta {
    background: var(--teal); border-radius: var(--radius);
    padding: 48px 40px; text-align: center; color: white; margin-top: 56px;
  }
  .resources-cta h2 { font-size: 1.6rem; font-weight: 800; margin-bottom: 10px; color: white; }
  .resources-cta p { font-size: 1rem; opacity: 0.85; margin-bottom: 28px; font-weight: 300; }
  .btn-white { background: white; color: var(--dark); }
  .btn-white:hover { background: #f5f5f5; transform: translateY(-1px); }
  @media (max-width: 768px) {
    .topics-grid { grid-template-columns: 1fr; }
    .resources-cta { padding: 32px 24px; }
  }
  @media (max-width: 1024px) {
    .topics-grid { grid-template-columns: repeat(2, 1fr); }
  }

/* ===== statistics-pages ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
  html { scroll-behavior: smooth; }
  body { font-family: 'DM Sans', sans-serif; color: var(--dark); background: var(--white); line-height: 1.6; -webkit-font-smoothing: antialiased; }
  h1,h2,h3,h4,h5 { font-family: 'Sora', sans-serif; line-height: 1.15; letter-spacing: -0.02em; }
  a { color: inherit; }
  nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    background: #ffffff; border-bottom: 1px solid var(--border);
    padding: 0 5%; height: 68px;
    display: flex; align-items: center; justify-content: space-between;
    transition: box-shadow 0.3s;
  }
  nav.scrolled { box-shadow: 0 2px 20px rgba(0,0,0,0.06); }
  .nav-logo { display: flex; align-items: center; text-decoration: none; flex-shrink: 0; }
  .nav-logo-img { height: 44px; width: auto; display: block; max-height: none; max-width: none; }
  .nav-links { display: flex; align-items: center; gap: 32px; list-style: none; }
  .nav-links a { text-decoration: none; color: var(--mid); font-size: 0.92rem; font-weight: 500; transition: color 0.2s; }
  .nav-links a:hover { color: var(--teal); }
  .nav-cta { display: flex; align-items: center; gap: 12px; }
  .nav-phone { font-size: 0.88rem; color: var(--mid); font-weight: 500; }
  .btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 12px 24px; border-radius: 8px;
    font-family: 'Sora', sans-serif; font-weight: 600; font-size: 0.9rem;
    cursor: pointer; text-decoration: none; transition: all 0.2s; border: none;
  }
  .btn-primary { background: var(--teal); color: white; }
  .btn-primary:hover { background: #0c5e57; transform: translateY(-1px); box-shadow: 0 8px 24px rgba(15,118,110,0.28); }
  .btn-secondary { background: transparent; color: var(--dark); border: 1.5px solid var(--border); }
  .btn-secondary:hover { border-color: var(--teal); color: var(--teal); transform: translateY(-1px); }
  .btn-lg { padding: 15px 32px; font-size: 1rem; border-radius: 10px; }
  .hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 4px; }
  .hamburger span { display: block; width: 22px; height: 2px; background: var(--dark); border-radius: 2px; }
  section { padding: 80px 5%; }
  .section-inner { max-width: 1160px; margin: 0 auto; }
  .section-tag {
    display: inline-block; font-family: 'Sora', sans-serif;
    font-size: 0.72rem; font-weight: 700; text-transform: uppercase;
    letter-spacing: 0.1em; color: var(--teal); background: var(--teal-bg);
    padding: 5px 12px; border-radius: 100px; margin-bottom: 16px;
  }
  .section-title { font-size: clamp(1.8rem, 3.5vw, 2.6rem); font-weight: 800; color: var(--dark); margin-bottom: 16px; }
  .section-sub { font-size: 1.05rem; color: var(--soft); max-width: 560px; line-height: 1.7; font-weight: 300; }
  .section-header { margin-bottom: 48px; }
  footer { background: #0A0A0A; padding: 60px 5% 32px; }
  .footer-inner { max-width: 1160px; margin: 0 auto; }
  .footer-top {
    display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 48px; padding-bottom: 48px;
    border-bottom: 1px solid rgba(255,255,255,0.08); margin-bottom: 32px;
  }
  .footer-brand p { color: rgba(255,255,255,0.45); font-size: 0.88rem; line-height: 1.7; margin-top: 14px; font-weight: 300; max-width: 260px; }
  .footer-logo { display: flex; align-items: center; overflow: visible; max-height: none; }
  .footer-logo-img { height: 64px; width: auto; display: block; max-height: none; max-width: none; mix-blend-mode: screen; opacity: 0.95; }
  .footer-col-title { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: rgba(255,255,255,0.5); margin-bottom: 16px; }
  .footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }
  .footer-col a { color: rgba(255,255,255,0.7); text-decoration: none; font-size: 0.88rem; transition: color 0.2s; }
  .footer-col a:hover { color: var(--teal-light); }
  .footer-bottom { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 16px; }
  .footer-copy { color: rgba(255,255,255,0.3); font-size: 0.82rem; }
  .footer-phone { color: rgba(255,255,255,0.5); font-size: 0.88rem; }
  @media (max-width: 768px) {
    section { padding: 64px 5%; }
    .nav-links { display: none; }
    .hamburger { display: flex; }
    .footer-top { grid-template-columns: 1fr; gap: 32px; }
    .nav-logo-img { height: 36px; }
    .footer-logo-img { height: 52px; }
  }

.topic-hero {
    padding-top: 68px; background: var(--white);
    border-bottom: 1px solid var(--border);
  }
  .topic-hero-inner {
    max-width: 1160px; margin: 0 auto;
    padding: 64px 5% 56px;
    display: grid; grid-template-columns: 1fr 340px; gap: 64px; align-items: start;
  }
  .breadcrumb { display: flex; align-items: center; gap: 8px; font-size: 0.82rem; color: var(--soft); margin-bottom: 20px; }
  .breadcrumb a { color: var(--teal); text-decoration: none; font-weight: 500; }
  .breadcrumb a:hover { text-decoration: underline; }
  .breadcrumb-sep { color: var(--border); }
  .page-headline { font-size: clamp(2rem, 4vw, 3rem); font-weight: 800; color: var(--dark); margin-bottom: 16px; }
  .page-sub { font-size: 1.05rem; color: var(--mid); line-height: 1.7; font-weight: 300; max-width: 580px; }
  .topic-meta { display: flex; gap: 20px; margin-top: 24px; flex-wrap: wrap; }
  .meta-pill {
    display: flex; align-items: center; gap: 6px;
    background: var(--teal-bg); color: var(--teal);
    padding: 6px 14px; border-radius: 100px;
    font-size: 0.8rem; font-weight: 600; font-family: 'Sora', sans-serif;
  }
  .sidebar-card {
    background: var(--teal); color: white;
    border-radius: var(--radius); padding: 32px 28px;
    position: sticky; top: 88px;
  }
  .sidebar-card .sidebar-card-title { font-size: 1.1rem; font-weight: 800; margin-bottom: 8px; color: white; }
  .sidebar-card p { font-size: 0.9rem; opacity: 0.85; margin-bottom: 24px; font-weight: 300; line-height: 1.6; }
  .btn-white { background: white; color: var(--dark); }
  .btn-white:hover { background: #f5f5f5; transform: translateY(-1px); }
  .sidebar-card .btn { width: 100%; justify-content: center; }
  .sidebar-reassure { font-size: 0.78rem; opacity: 0.7; text-align: center; margin-top: 12px; }
  .content-body { max-width: 1160px; margin: 0 auto; padding: 0 5%; }
  .content-layout { display: grid; grid-template-columns: 1fr 340px; gap: 64px; align-items: start; padding: 64px 0; }
  .content-main h2 {
    font-size: 1.5rem; font-weight: 800; color: var(--dark);
    margin: 40px 0 16px; padding-top: 40px;
    border-top: 1px solid var(--border);
  }
  .content-main h2:first-child { margin-top: 0; padding-top: 0; border-top: none; }
  .content-main h3 { font-size: 1.1rem; font-weight: 700; color: var(--dark); margin: 28px 0 10px; }
  .content-main p { font-size: 0.97rem; color: var(--mid); line-height: 1.8; margin-bottom: 16px; font-weight: 300; }
  .content-main ul, .content-main ol {
    padding-left: 20px; margin-bottom: 16px;
  }
  .content-main li { font-size: 0.97rem; color: var(--mid); line-height: 1.8; font-weight: 300; margin-bottom: 6px; }
  .worked-example {
    background: var(--teal-bg); border: 1px solid rgba(20,184,166,0.2);
    border-radius: var(--radius); padding: 28px; margin: 24px 0;
  }
  .worked-example .ex-label {
    font-family: 'Sora', sans-serif; font-size: 0.72rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.1em; color: var(--teal);
    margin-bottom: 12px; display: block;
  }
  .worked-example .ex-question {
    font-family: 'Sora', sans-serif; font-size: 1.05rem; font-weight: 700;
    color: var(--dark); margin-bottom: 16px;
  }
  .worked-example .ex-step {
    display: flex; gap: 12px; margin-bottom: 10px; align-items: flex-start;
  }
  .worked-example .step-num {
    width: 24px; height: 24px; border-radius: 50%;
    background: var(--teal); color: white;
    font-family: 'Sora', sans-serif; font-size: 0.75rem; font-weight: 700;
    display: flex; align-items: center; justify-content: center; flex-shrink: 0;
    margin-top: 2px;
  }
  .worked-example .step-text { font-size: 0.95rem; color: var(--mid); line-height: 1.7; }
  .worked-example .step-text strong { color: var(--dark); font-weight: 600; }
  .answer-box {
    background: white; border: 1.5px solid var(--teal);
    border-radius: var(--radius-sm); padding: 12px 16px;
    margin-top: 16px; display: flex; align-items: center; gap: 10px;
  }
  .answer-box .ans-label {
    font-family: 'Sora', sans-serif; font-size: 0.75rem; font-weight: 700;
    color: var(--teal); text-transform: uppercase; letter-spacing: 0.06em; white-space: nowrap;
  }
  .answer-box .ans-value { font-size: 1rem; font-weight: 600; color: var(--dark); }
  .practice-questions { margin: 24px 0; }
  .pq-item {
    background: white; border: 1px solid var(--border);
    border-radius: var(--radius-sm); padding: 20px 24px;
    margin-bottom: 12px; display: flex; gap: 16px; align-items: flex-start;
  }
  .pq-num {
    font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700;
    color: var(--teal); min-width: 28px;
  }
  .pq-text { font-size: 0.95rem; color: var(--dark); line-height: 1.6; }
  .pq-diff {
    margin-left: auto; font-size: 0.72rem; font-weight: 700;
    font-family: 'Sora', sans-serif; padding: 3px 8px; border-radius: 100px;
    white-space: nowrap; align-self: center;
  }
  .diff-f { background: #DCFCE7; color: #166534; }
  .diff-h { background: #FEF9C3; color: #854D0E; }
  .diff-hh { background: #FEE2E2; color: #991B1B; }
  .answers-section {
    background: var(--bg-alt); border-radius: var(--radius);
    padding: 32px; margin-top: 32px;
  }
  .answers-section h3 { font-size: 1.1rem; font-weight: 700; margin-bottom: 20px; }
  .answer-row {
    display: flex; gap: 12px; padding: 10px 0;
    border-bottom: 1px solid var(--border); align-items: baseline;
  }
  .answer-row:last-child { border-bottom: none; }
  .ans-q { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; color: var(--teal); min-width: 28px; }
  .ans-a { font-size: 0.92rem; color: var(--dark); }
  .ans-note { font-size: 0.82rem; color: var(--soft); margin-left: 4px; }
  .toc {
    background: var(--bg-alt); border-radius: var(--radius);
    padding: 24px 28px; margin-bottom: 32px;
  }
  .toc-title { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--soft); margin-bottom: 14px; }
  .toc ul { list-style: none; display: flex; flex-direction: column; gap: 8px; }
  .toc a { color: var(--teal); text-decoration: none; font-size: 0.9rem; font-weight: 500; }
  .toc a:hover { text-decoration: underline; }
  .content-sidebar { position: sticky; top: 88px; display: flex; flex-direction: column; gap: 20px; }
  .cta-sidebar {
    background: var(--teal); color: white;
    border-radius: var(--radius); padding: 28px 24px;
  }
  .cta-sidebar .cta-sidebar-title { font-size: 1rem; font-weight: 800; margin-bottom: 8px; color: white; }
  .cta-sidebar p { font-size: 0.85rem; opacity: 0.85; margin-bottom: 20px; font-weight: 300; line-height: 1.6; }
  .cta-sidebar .btn { width: 100%; justify-content: center; }
  .cta-sidebar .sidebar-reassure { font-size: 0.75rem; opacity: 0.65; text-align: center; margin-top: 10px; }
  .next-topics { background: white; border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; }
  .next-topics-title { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--soft); margin-bottom: 14px; }
  .next-link {
    display: flex; align-items: center; gap: 10px; padding: 10px 0;
    border-bottom: 1px solid var(--border); text-decoration: none; color: var(--mid);
    font-size: 0.88rem; font-weight: 500; transition: color 0.2s;
  }
  .next-link:last-child { border-bottom: none; }
  .next-link:hover { color: var(--teal); }
  .next-link-icon { font-size: 1rem; }
  @media (max-width: 1024px) {
    .topic-hero-inner { grid-template-columns: 1fr; gap: 32px; }
    .content-layout { grid-template-columns: 1fr; gap: 32px; }
    .content-sidebar { position: static; }
    .sidebar-card { display: none; }
  }

.mistakes-section { margin-top: 40px; }
  .mistake-item {
    background: white; border: 1px solid var(--border);
    border-left: 4px solid #EF4444;
    border-radius: var(--radius-sm); padding: 20px 24px;
    margin-bottom: 14px;
  }
  .mistake-label {
    font-family: 'Sora', sans-serif; font-size: 0.72rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.1em; color: #EF4444;
    margin-bottom: 8px; display: block;
  }
  .mistake-title { font-family: 'Sora', sans-serif; font-size: 0.97rem; font-weight: 700; color: var(--dark); margin-bottom: 6px; }
  .mistake-text { font-size: 0.92rem; color: var(--mid); line-height: 1.7; }
  .mistake-text strong { color: var(--dark); }
  .answers-group { margin-bottom: 28px; }
  .answers-group h4 {
    font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.08em; color: var(--soft);
    margin-bottom: 14px; border-bottom: 1px solid var(--border); padding-bottom: 8px;
  }
  .diagram-box {
    background: white; border: 1px solid var(--border);
    border-radius: var(--radius); padding: 24px 24px 12px; margin: 24px 0;
  }
  .diagram-caption {
    font-size: 0.85rem; color: var(--soft); text-align: center;
    margin-top: 8px; font-weight: 300; line-height: 1.6;
  }
  .diagram-box svg { display: block; width: 100%; height: auto; }
  .solution-toggle {
    background: white; border: 1px solid var(--border);
    border-radius: var(--radius-sm); margin-top: 14px; overflow: hidden;
  }
  .solution-toggle summary {
    cursor: pointer; list-style: none; padding: 12px 16px;
    display: flex; align-items: center; gap: 8px;
    font-family: 'Sora', sans-serif; font-size: 0.85rem; font-weight: 700;
    color: var(--teal); background: var(--teal-bg);
  }
  .solution-toggle summary::-webkit-details-marker { display: none; }
  .solution-toggle summary::before {
    content: '+'; font-size: 1rem; font-weight: 700; width: 14px; flex-shrink: 0;
  }
  .solution-toggle[open] summary::before { content: '\2212'; }
  .solution-toggle[open] summary { border-bottom: 1px solid rgba(20,184,166,0.2); }
  .solution-body { padding: 18px 20px; }
  .solution-step { display: flex; gap: 12px; margin-bottom: 10px; align-items: flex-start; }
  .solution-step:last-of-type { margin-bottom: 0; }
  .solution-num {
    width: 22px; height: 22px; border-radius: 50%;
    background: var(--teal); color: white;
    font-family: 'Sora', sans-serif; font-size: 0.72rem; font-weight: 700;
    display: flex; align-items: center; justify-content: center; flex-shrink: 0;
    margin-top: 2px;
  }
  .solution-text { font-size: 0.92rem; color: var(--mid); line-height: 1.7; }
  .solution-text strong { color: var(--dark); font-weight: 600; }
  .solution-final {
    margin-top: 12px; padding-top: 12px; border-top: 1px solid var(--border);
    font-family: 'Sora', sans-serif; font-weight: 700; color: var(--dark); font-size: 0.95rem;
  }
  .frac {
    display: inline-flex; flex-direction: column; align-items: center;
    vertical-align: middle; text-align: center; margin: 0 4px; line-height: 1.3;
    font-size: 0.9em;
  }
  .frac-num, .frac-den { display: block; padding: 0 3px; white-space: nowrap; }
  .frac-line { align-self: stretch; height: 0; border-top: 1.5px solid currentColor; margin: 2px 0; }
  .exam-tips-section { margin-top: 40px; }
  .tip-item {
    background: var(--teal-bg); border: 1px solid rgba(20,184,166,0.2);
    border-left: 4px solid var(--teal);
    border-radius: var(--radius-sm); padding: 20px 24px;
    margin-bottom: 14px;
  }
  .tip-label {
    font-family: 'Sora', sans-serif; font-size: 0.72rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.1em; color: var(--teal);
    margin-bottom: 8px; display: flex; align-items: center; gap: 6px;
  }
  .tip-title { font-family: 'Sora', sans-serif; font-size: 0.97rem; font-weight: 700; color: var(--dark); margin-bottom: 6px; }
  .tip-text { font-size: 0.92rem; color: var(--mid); line-height: 1.7; }
  .tip-text strong { color: var(--dark); }
  .data-table {
    width: 100%; border-collapse: collapse; margin: 16px 0 8px;
    font-size: 0.9rem; background: white;
  }
  .data-table th {
    background: var(--teal-bg); color: var(--teal);
    font-family: 'Sora', sans-serif; font-weight: 700; font-size: 0.76rem;
    text-transform: uppercase; letter-spacing: 0.05em;
    text-align: left; padding: 10px 14px; border-bottom: 2px solid var(--teal);
  }
  .data-table td {
    padding: 9px 14px; border-bottom: 1px solid var(--border);
    color: var(--dark); font-weight: 500;
  }
  .data-table tr:last-child td { border-bottom: none; }
  .pq-content { flex: 1; display: flex; flex-direction: column; gap: 10px; }
  .pq-table {
    width: 100%; max-width: 420px; border-collapse: collapse;
    font-size: 0.85rem; background: var(--bg-alt); border-radius: 6px; overflow: hidden;
  }
  .pq-table th {
    background: var(--border); color: var(--mid);
    font-family: 'Sora', sans-serif; font-weight: 700; font-size: 0.7rem;
    text-transform: uppercase; letter-spacing: 0.04em;
    text-align: left; padding: 7px 12px;
  }
  .pq-table td { padding: 7px 12px; color: var(--dark); border-top: 1px solid var(--border); }

.subtopic-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 20px;
    margin: 24px 0 40px;
  }
  .subtopic-card {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    text-decoration: none;
    color: var(--dark);
    display: flex;
    flex-direction: column;
    gap: 8px;
    transition: transform 0.2s, box-shadow 0.2s;
    position: relative;
    overflow: hidden;
  }
  .subtopic-card::before {
    content: '';
    position: absolute;
    bottom: 0; left: 0; right: 0;
    height: 3px;
    background: var(--teal);
    transform: scaleX(0);
    transition: transform 0.2s;
  }
  .subtopic-card:hover { transform: translateY(-4px); box-shadow: 0 12px 32px rgba(0,0,0,0.07); }
  .subtopic-card:hover::before { transform: scaleX(1); }
  .subtopic-icon { font-size: 1.6rem; margin-bottom: 4px; }
  .subtopic-title { font-family: 'Sora', sans-serif; font-size: 1rem; font-weight: 700; color: var(--dark); }
  .subtopic-desc { font-size: 0.88rem; color: var(--soft); line-height: 1.6; flex: 1; }
  .subtopic-cta {
    font-family: 'Sora', sans-serif; font-size: 0.78rem; font-weight: 700;
    color: var(--teal); text-transform: uppercase; letter-spacing: 0.06em; margin-top: 8px;
  }

/* ===== resources ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
  html { scroll-behavior: smooth; }
  body { font-family: 'DM Sans', sans-serif; color: var(--dark); background: var(--white); line-height: 1.6; -webkit-font-smoothing: antialiased; }
  h1,h2,h3,h4,h5 { font-family: 'Sora', sans-serif; line-height: 1.15; letter-spacing: -0.02em; }
  a { color: inherit; }
  nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    background: #ffffff; border-bottom: 1px solid var(--border);
    padding: 0 5%; height: 68px;
    display: flex; align-items: center; justify-content: space-between;
    transition: box-shadow 0.3s;
  }
  nav.scrolled { box-shadow: 0 2px 20px rgba(0,0,0,0.06); }
  .nav-logo { display: flex; align-items: center; text-decoration: none; flex-shrink: 0; }
  .nav-logo-img { height: 44px; width: auto; display: block; max-height: none; max-width: none; }
  .nav-links { display: flex; align-items: center; gap: 32px; list-style: none; }
  .nav-links a { text-decoration: none; color: var(--mid); font-size: 0.92rem; font-weight: 500; transition: color 0.2s; }
  .nav-links a:hover { color: var(--teal); }
  .nav-cta { display: flex; align-items: center; gap: 12px; }
  .nav-phone { font-size: 0.88rem; color: var(--mid); font-weight: 500; }
  .btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 12px 24px; border-radius: 8px;
    font-family: 'Sora', sans-serif; font-weight: 600; font-size: 0.9rem;
    cursor: pointer; text-decoration: none; transition: all 0.2s; border: none;
  }
  .btn-primary { background: var(--teal); color: white; }
  .btn-primary:hover { background: #0c5e57; transform: translateY(-1px); box-shadow: 0 8px 24px rgba(15,118,110,0.28); }
  .btn-secondary { background: transparent; color: var(--dark); border: 1.5px solid var(--border); }
  .btn-secondary:hover { border-color: var(--teal); color: var(--teal); transform: translateY(-1px); }
  .btn-lg { padding: 15px 32px; font-size: 1rem; border-radius: 10px; }
  .hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 4px; }
  .hamburger span { display: block; width: 22px; height: 2px; background: var(--dark); border-radius: 2px; }
  section { padding: 80px 5%; }
  .section-inner { max-width: 1160px; margin: 0 auto; }
  .section-tag {
    display: inline-block; font-family: 'Sora', sans-serif;
    font-size: 0.72rem; font-weight: 700; text-transform: uppercase;
    letter-spacing: 0.1em; color: var(--teal); background: var(--teal-bg);
    padding: 5px 12px; border-radius: 100px; margin-bottom: 16px;
  }
  .section-title { font-size: clamp(1.8rem, 3.5vw, 2.6rem); font-weight: 800; color: var(--dark); margin-bottom: 16px; }
  .section-sub { font-size: 1.05rem; color: var(--soft); max-width: 560px; line-height: 1.7; font-weight: 300; }
  .section-header { margin-bottom: 48px; }
  footer { background: #0A0A0A; padding: 60px 5% 32px; }
  .footer-inner { max-width: 1160px; margin: 0 auto; }
  .footer-top {
    display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 48px; padding-bottom: 48px;
    border-bottom: 1px solid rgba(255,255,255,0.08); margin-bottom: 32px;
  }
  .footer-brand p { color: rgba(255,255,255,0.45); font-size: 0.88rem; line-height: 1.7; margin-top: 14px; font-weight: 300; max-width: 260px; }
  .footer-logo { display: flex; align-items: center; overflow: visible; max-height: none; }
  .footer-logo-img { height: 64px; width: auto; display: block; max-height: none; max-width: none; mix-blend-mode: screen; opacity: 0.95; }
  .footer-col-title { font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: rgba(255,255,255,0.5); margin-bottom: 16px; }
  .footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }
  .footer-col a { color: rgba(255,255,255,0.7); text-decoration: none; font-size: 0.88rem; transition: color 0.2s; }
  .footer-col a:hover { color: var(--teal-light); }
  .footer-bottom { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 16px; }
  .footer-copy { color: rgba(255,255,255,0.3); font-size: 0.82rem; }
  .footer-phone { color: rgba(255,255,255,0.5); font-size: 0.88rem; }
  @media (max-width: 768px) {
    section { padding: 64px 5%; }
    .nav-links { display: none; }
    .hamburger { display: flex; }
    .footer-top { grid-template-columns: 1fr; gap: 32px; }
    .nav-logo-img { height: 36px; }
    .footer-logo-img { height: 52px; }
  }

.resources-hero {
    padding-top: 68px; background: var(--white);
    border-bottom: 1px solid var(--border);
  }
  .resources-hero-inner {
    max-width: 1160px; margin: 0 auto;
    padding: 64px 5% 56px;
  }
  .breadcrumb {
    display: flex; align-items: center; gap: 8px;
    font-size: 0.82rem; color: var(--soft); margin-bottom: 20px;
  }
  .breadcrumb a { color: var(--teal); text-decoration: none; font-weight: 500; }
  .breadcrumb a:hover { text-decoration: underline; }
  .breadcrumb-sep { color: var(--border); }
  .page-headline { font-size: clamp(2rem, 4vw, 3rem); font-weight: 800; color: var(--dark); margin-bottom: 16px; }
  .page-sub { font-size: 1.05rem; color: var(--mid); line-height: 1.7; font-weight: 300; max-width: 580px; }
  .topics-grid {
    display: grid; grid-template-columns: repeat(3, 1fr);
    gap: 20px;
  }
  .topic-card {
    background: white; border: 1px solid var(--border);
    border-radius: var(--radius); padding: 28px;
    text-decoration: none; color: inherit;
    transition: all 0.22s; display: block;
    position: relative; overflow: hidden;
  }
  .topic-card::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
    background: linear-gradient(90deg, var(--teal), var(--teal-light));
    transform: scaleX(0); transform-origin: left; transition: transform 0.3s;
  }
  .topic-card:hover { transform: translateY(-5px); box-shadow: 0 16px 40px rgba(0,0,0,0.07); }
  .topic-card:hover::before { transform: scaleX(1); }
  .topic-icon { font-size: 1.8rem; margin-bottom: 14px; display: block; }
  .topic-title { font-family: 'Sora', sans-serif; font-size: 1.05rem; font-weight: 700; color: var(--dark); margin-bottom: 8px; }
  .topic-desc { font-size: 0.88rem; color: var(--soft); line-height: 1.6; margin-bottom: 16px; }
  .topic-count { font-size: 0.78rem; color: var(--teal); font-weight: 600; font-family: 'Sora', sans-serif; }
  .topic-card.coming-soon { opacity: 0.55; cursor: default; pointer-events: none; }
  .coming-badge {
    position: absolute; top: 16px; right: 16px;
    background: var(--bg-alt); color: var(--soft);
    font-size: 0.68rem; font-weight: 700; font-family: 'Sora', sans-serif;
    padding: 3px 8px; border-radius: 100px; text-transform: uppercase;
    letter-spacing: 0.06em;
  }
  .resources-cta {
    background: var(--teal); border-radius: var(--radius);
    padding: 48px 40px; text-align: center; color: white; margin-top: 56px;
  }
  .resources-cta h2 { font-size: 1.6rem; font-weight: 800; margin-bottom: 10px; color: white; }
  .resources-cta p { font-size: 1rem; opacity: 0.85; margin-bottom: 28px; font-weight: 300; }
  .btn-white { background: white; color: var(--dark); }
  .btn-white:hover { background: #f5f5f5; transform: translateY(-1px); }
  @media (max-width: 768px) {
    .topics-grid { grid-template-columns: 1fr; }
    .resources-cta { padding: 32px 24px; }
  }
  @media (max-width: 1024px) {
    .topics-grid { grid-template-columns: repeat(2, 1fr); }
  }

/* ===== home ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

  html { scroll-behavior: smooth; }
  :target { scroll-margin-top: 80px; }

  body {
    font-family: 'DM Sans', sans-serif;
    color: var(--dark);
    background: var(--white);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
  }

  h1, h2, h3, h4, h5 {
    font-family: 'Sora', sans-serif;
    line-height: 1.15;
    letter-spacing: -0.02em;
  }

  /* ─── NAV ─── */
  nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    background: #ffffff;
    border-bottom: 1px solid var(--border);
    padding: 0 5%;
    height: 68px;
    display: flex; align-items: center; justify-content: space-between;
    transition: box-shadow 0.3s;
  }
  nav.scrolled { box-shadow: 0 2px 20px rgba(0,0,0,0.06); }

  .nav-logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    flex-shrink: 0;
    flex-grow: 0;
    overflow: visible;
    max-height: none;
    padding: 0;
    background: none;
    border: none;
    box-shadow: none;
  }
  .nav-logo-img {
    height: 44px;
    width: auto;
    display: block;
    max-height: none;
    max-width: none;
  }

  .nav-links {
    display: flex; align-items: center; gap: 32px;
    list-style: none;
  }
  .nav-links a {
    text-decoration: none; color: var(--mid);
    font-size: 0.92rem; font-weight: 500;
    transition: color 0.2s;
  }
  .nav-links a:hover { color: var(--teal); }

  .nav-cta {
    display: flex; align-items: center; gap: 12px;
  }
  .nav-phone {
    font-size: 0.88rem; color: var(--mid); font-weight: 500;
  }

  .btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 12px 24px;
    border-radius: 8px;
    font-family: 'Sora', sans-serif;
    font-weight: 600; font-size: 0.9rem;
    cursor: pointer; text-decoration: none;
    transition: all 0.2s; border: none;
  }
  .btn-primary {
    background: var(--teal); color: white;
  }
  .btn-primary:hover {
    background: #0c5e57; transform: translateY(-1px);
    box-shadow: 0 8px 24px rgba(15,118,110,0.28);
  }
  .btn-secondary {
    background: transparent; color: var(--dark);
    border: 1.5px solid var(--border);
  }
  .btn-secondary:hover {
    border-color: var(--teal); color: var(--teal);
    transform: translateY(-1px);
  }
  .btn-lg { padding: 15px 32px; font-size: 1rem; border-radius: 10px; }
  .btn-ghost {
    background: transparent; color: var(--teal);
    border: 1.5px solid var(--teal);
  }
  .btn-ghost:hover {
    background: var(--teal); color: white;
    transform: translateY(-1px);
  }

  .hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 4px; }
  .hamburger span { display: block; width: 22px; height: 2px; background: var(--dark); border-radius: 2px; transition: 0.3s; }

  /* ─── HERO ─── */
  #hero {
    padding-top: 68px;
    min-height: 100vh;
    display: flex; align-items: center;
    background: var(--white);
    position: relative; overflow: hidden;
  }

  .hero-bg-shape {
    position: absolute; top: -120px; right: -180px;
    width: 700px; height: 700px;
    background: radial-gradient(circle, rgba(20,184,166,0.08) 0%, transparent 70%);
    border-radius: 50%; pointer-events: none;
  }
  .hero-bg-shape-2 {
    position: absolute; bottom: -80px; left: -100px;
    width: 500px; height: 500px;
    background: radial-gradient(circle, rgba(15,118,110,0.05) 0%, transparent 70%);
    border-radius: 50%; pointer-events: none;
  }

  .hero-inner {
    max-width: 1160px; margin: 0 auto;
    padding: 80px 5%;
    display: grid; grid-template-columns: 1fr 1fr;
    gap: 80px; align-items: center;
    position: relative; z-index: 1;
    width: 100%;
  }

  .hero-badge {
    display: inline-flex; align-items: center; gap: 8px;
    background: var(--teal-bg); border: 1px solid rgba(20,184,166,0.3);
    color: var(--teal); padding: 6px 14px; border-radius: 100px;
    font-size: 0.8rem; font-weight: 600; font-family: 'Sora', sans-serif;
    text-transform: uppercase; letter-spacing: 0.06em;
    margin-bottom: 24px;
  }
  .hero-badge-dot {
    width: 7px; height: 7px; border-radius: 50%;
    background: var(--teal-light); animation: pulse 2s infinite;
  }
  @keyframes pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.6; transform: scale(1.3); }
  }

  .hero-headline {
    font-size: clamp(2.4rem, 5vw, 3.6rem);
    font-weight: 800;
    color: var(--dark);
    margin-bottom: 20px;
    line-height: 1.1;
  }
  .hero-headline .accent { color: var(--teal); }

  .hero-sub {
    font-size: 1.12rem;
    color: var(--mid);
    line-height: 1.7;
    max-width: 480px;
    margin-bottom: 36px;
    font-weight: 300;
  }

  .hero-actions {
    display: flex; align-items: center; gap: 14px; flex-wrap: wrap;
    margin-bottom: 48px;
  }

  .hero-trust {
    display: flex; align-items: center; gap: 20px; flex-wrap: wrap;
  }
  .trust-item {
    display: flex; align-items: center; gap: 8px;
    font-size: 0.83rem; color: var(--soft); font-weight: 500;
  }
  .trust-item svg { color: var(--teal); flex-shrink: 0; }

  .hero-visual {
    position: relative;
  }
  .hero-card-main {
    background: white;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    padding: 32px;
    box-shadow: 0 24px 64px rgba(0,0,0,0.08);
    position: relative; z-index: 2;
  }
  .hero-card-label {
    font-family: 'Sora', sans-serif;
    font-size: 0.72rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.1em;
    color: var(--teal); margin-bottom: 16px;
  }
  .progress-row {
    display: flex; align-items: center; justify-content: space-between;
    margin-bottom: 10px;
  }
  .progress-label { font-size: 0.88rem; color: var(--mid); font-weight: 500; }
  .progress-grade {
    font-family: 'Sora', sans-serif;
    font-weight: 700; font-size: 0.88rem;
  }
  .progress-bar-track {
    height: 6px; background: #F0F0F0; border-radius: 10px; overflow: hidden;
    margin-bottom: 18px;
  }
  .progress-bar-fill {
    height: 100%; border-radius: 10px;
    background: linear-gradient(90deg, var(--teal), var(--teal-light));
    animation: grow 1.5s ease-out forwards;
    transform-origin: left;
  }
  @keyframes grow { from { width: 0; } }

  .hero-card-floating {
    position: absolute;
    background: white; border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    padding: 14px 18px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.1);
    font-family: 'Sora', sans-serif; font-size: 0.82rem;
    z-index: 3;
  }
  .float-1 { bottom: -24px; left: -32px; }
  .float-2 { top: -20px; right: -20px; }
  .float-stat { font-size: 1.4rem; font-weight: 800; color: var(--teal); display: block; }
  .float-desc { color: var(--soft); font-size: 0.76rem; font-weight: 500; }

  /* ─── SECTION COMMONS ─── */
  section { padding: 100px 5%; }
  .section-inner { max-width: 1160px; margin: 0 auto; }

  .section-tag {
    display: inline-block;
    font-family: 'Sora', sans-serif;
    font-size: 0.72rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.1em;
    color: var(--teal);
    background: var(--teal-bg);
    padding: 5px 12px; border-radius: 100px;
    margin-bottom: 16px;
  }
  .section-title {
    font-size: clamp(1.8rem, 3.5vw, 2.6rem);
    font-weight: 800; color: var(--dark);
    margin-bottom: 16px;
  }
  .section-sub {
    font-size: 1.05rem; color: var(--soft);
    max-width: 560px; line-height: 1.7;
    font-weight: 300;
  }
  .section-header { margin-bottom: 56px; }
  .section-header.center { text-align: center; }
  .section-header.center .section-sub { margin: 0 auto; }

  /* ─── PROBLEM ─── */
  #problem { background: var(--bg-alt); }

  .problem-grid {
    display: grid; grid-template-columns: 1fr 1fr;
    gap: 64px; align-items: center;
  }
  .problem-list {
    list-style: none; display: flex; flex-direction: column; gap: 16px;
    margin: 32px 0;
  }
  .problem-item {
    display: flex; align-items: flex-start; gap: 14px;
    padding: 18px 20px;
    background: white; border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    transition: border-color 0.2s, transform 0.2s;
  }
  .problem-item:hover { border-color: var(--teal-light); transform: translateX(4px); }
  .problem-icon {
    width: 36px; height: 36px; border-radius: 8px;
    background: #FFF1F0; display: flex; align-items: center; justify-content: center;
    font-size: 1rem; flex-shrink: 0;
  }
  .problem-text { font-size: 0.95rem; color: var(--mid); font-weight: 500; padding-top: 6px; }

  .problem-solution {
    font-size: 1.0rem; color: var(--mid); line-height: 1.8;
    font-weight: 300; margin-bottom: 28px;
  }
  .problem-visual {
    position: relative;
  }
  .problem-stat-card {
    background: var(--teal);
    color: white; border-radius: var(--radius);
    padding: 40px 36px;
    text-align: center;
  }
  .stat-big { font-family: 'Sora', sans-serif; font-size: 4rem; font-weight: 800; line-height: 1; }
  .stat-label { font-size: 1.0rem; opacity: 0.85; margin-top: 8px; font-weight: 300; }

  .stat-row {
    display: grid; grid-template-columns: 1fr 1fr;
    gap: 12px; margin-top: 16px;
  }
  .stat-mini {
    background: rgba(255,255,255,0.12);
    border-radius: var(--radius-sm); padding: 16px;
    text-align: center;
  }
  .stat-mini-val { font-family: 'Sora', sans-serif; font-size: 1.5rem; font-weight: 800; }
  .stat-mini-label { font-size: 0.78rem; opacity: 0.8; margin-top: 2px; }

  /* ─── HOW IT WORKS ─── */
  .steps-grid {
    display: grid; grid-template-columns: repeat(4, 1fr);
    gap: 24px;
  }
  .step-card {
    background: white; border: 1px solid var(--border);
    border-radius: var(--radius); padding: 32px 26px;
    transition: all 0.25s; position: relative;
    overflow: hidden;
  }
  .step-card::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
    background: linear-gradient(90deg, var(--teal), var(--teal-light));
    transform: scaleX(0); transform-origin: left;
    transition: transform 0.3s;
  }
  .step-card:hover { transform: translateY(-6px); box-shadow: 0 20px 48px rgba(0,0,0,0.08); }
  .step-card:hover::before { transform: scaleX(1); }

  .step-number {
    font-family: 'Sora', sans-serif;
    font-size: 0.7rem; font-weight: 800; color: var(--teal);
    text-transform: uppercase; letter-spacing: 0.1em; margin-bottom: 16px;
    opacity: 0.6;
  }
  .step-icon {
    width: 48px; height: 48px; border-radius: 12px;
    background: var(--teal-bg);
    display: flex; align-items: center; justify-content: center;
    font-size: 1.4rem; margin-bottom: 20px;
  }
  .step-title {
    font-family: 'Sora', sans-serif;
    font-size: 1.05rem; font-weight: 700; color: var(--dark);
    margin-bottom: 10px;
  }
  .step-desc { font-size: 0.9rem; color: var(--soft); line-height: 1.6; font-weight: 300; }

  /* ─── SUBJECTS ─── */
  #subjects { background: var(--bg-alt); }

  .subjects-grid {
    display: grid; grid-template-columns: repeat(4, 1fr);
    gap: 20px;
  }
  .subject-card {
    background: white; border: 1px solid var(--border);
    border-radius: var(--radius); padding: 36px 28px;
    text-align: center; transition: all 0.25s; cursor: default;
    position: relative;
  }
  .subject-card.featured {
    border-color: var(--teal);
    background: linear-gradient(135deg, #F0FDFA, white);
  }
  .subject-card.featured .subject-badge {
    position: absolute; top: 14px; right: 14px;
    background: var(--teal); color: white;
    font-size: 0.68rem; font-weight: 700; font-family: 'Sora', sans-serif;
    padding: 3px 8px; border-radius: 100px;
    text-transform: uppercase; letter-spacing: 0.06em;
  }
  .subject-card:hover { transform: translateY(-5px); box-shadow: 0 16px 40px rgba(0,0,0,0.07); }
  .subject-icon { font-size: 2.4rem; margin-bottom: 16px; display: block; }
  .subject-name {
    font-family: 'Sora', sans-serif;
    font-size: 1.1rem; font-weight: 700; color: var(--dark); margin-bottom: 8px;
  }
  .subject-levels { font-size: 0.82rem; color: var(--soft); font-weight: 400; }

  /* ─── RESULTS ─── */
  .results-grid {
    display: grid; grid-template-columns: 1fr 1fr;
    gap: 32px; align-items: start;
  }
  .grade-cards { display: flex; flex-direction: column; gap: 20px; }
  .grade-card {
    background: white; border: 1px solid var(--border);
    border-radius: var(--radius); padding: 28px;
    display: flex; align-items: center; gap: 24px;
  }
  .grade-arrow {
    display: flex; align-items: center; gap: 12px;
    font-family: 'Sora', sans-serif; font-weight: 800; font-size: 2.2rem;
  }
  .grade-from { color: #EF4444; }
  .grade-arrow-sym { font-size: 1.2rem; color: var(--soft); font-weight: 300; }
  .grade-to { color: var(--teal); }
  .grade-info .grade-student { font-size: 0.9rem; font-weight: 600; color: var(--dark); }
  .grade-info .grade-detail { font-size: 0.82rem; color: var(--soft); margin-top: 2px; }

  .outcomes-list { display: flex; flex-direction: column; gap: 16px; }
  .outcome-item {
    display: flex; align-items: flex-start; gap: 14px;
    padding: 20px 22px; background: white;
    border: 1px solid var(--border); border-radius: var(--radius-sm);
  }
  .outcome-check {
    width: 28px; height: 28px; border-radius: 50%;
    background: var(--teal); color: white;
    display: flex; align-items: center; justify-content: center;
    font-size: 0.75rem; flex-shrink: 0;
  }
  .outcome-text { font-size: 0.94rem; color: var(--mid); line-height: 1.6; font-weight: 400; }

  /* ─── TESTIMONIALS ─── */
  #testimonials { background: var(--bg-alt); }

  .testimonials-grid {
    display: grid; grid-template-columns: repeat(3, 1fr);
    gap: 24px;
  }
  .testimonial-card {
    background: white; border: 1px solid var(--border);
    border-radius: var(--radius); padding: 32px;
    transition: all 0.25s;
  }
  .testimonial-card:hover { transform: translateY(-4px); box-shadow: 0 16px 40px rgba(0,0,0,0.07); }
  .testimonial-card.featured { border-color: var(--teal); }

  .stars {
    color: #F59E0B; font-size: 0.9rem; letter-spacing: 2px; margin-bottom: 18px;
  }
  .testimonial-quote {
    font-size: 0.95rem; color: var(--mid); line-height: 1.75;
    font-style: italic; font-weight: 300; margin-bottom: 24px;
    flex-grow: 1;
  }
  .testimonial-author {
    display: flex; align-items: center; gap: 12px;
    padding-top: 20px; border-top: 1px solid var(--border);
  }
  .author-avatar {
    width: 42px; height: 42px; border-radius: 50%;
    background: var(--teal); display: flex; align-items: center;
    justify-content: center; color: white;
    font-family: 'Sora', sans-serif; font-weight: 700; font-size: 0.9rem;
    flex-shrink: 0;
  }
  .author-name { font-family: 'Sora', sans-serif; font-size: 0.9rem; font-weight: 700; }
  .author-role { font-size: 0.78rem; color: var(--soft); margin-top: 1px; }

  /* ─── TUTOR ─── */
  .tutor-grid {
    display: grid; grid-template-columns: 1fr 1.6fr;
    gap: 80px; align-items: center;
  }
  .tutor-photo-wrap {
    position: relative;
  }
  .tutor-photo {
    width: 100%; aspect-ratio: 4/5;
    border-radius: var(--radius);
    background: linear-gradient(135deg, var(--teal-bg), var(--teal-pale));
    display: flex; align-items: center; justify-content: center;
    font-size: 5rem;
    position: relative; overflow: hidden;
  }
  .tutor-photo-badge {
    position: absolute; bottom: 20px; left: 50%; transform: translateX(-50%);
    background: white; border-radius: 100px;
    padding: 10px 20px; white-space: nowrap;
    box-shadow: 0 8px 24px rgba(0,0,0,0.12);
    display: flex; align-items: center; gap: 8px;
    font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700;
  }
  .tutor-badge-dot { width: 8px; height: 8px; background: var(--teal); border-radius: 50%; }

  .tutor-name {
    font-family: 'Sora', sans-serif; font-size: 2rem; font-weight: 800;
    color: var(--dark); margin-bottom: 4px;
  }
  .tutor-role { color: var(--teal); font-weight: 600; font-size: 1rem; margin-bottom: 24px; }
  .tutor-bio { font-size: 1.0rem; color: var(--mid); line-height: 1.8; font-weight: 300; margin-bottom: 32px; }

  .tutor-credentials {
    display: grid; grid-template-columns: 1fr 1fr;
    gap: 14px; margin-bottom: 32px;
  }
  .credential {
    display: flex; align-items: center; gap: 10px;
    background: var(--bg-alt); border-radius: var(--radius-sm);
    padding: 12px 16px;
  }
  .credential-icon { font-size: 1.1rem; }
  .credential-text { font-size: 0.85rem; color: var(--mid); font-weight: 500; }

  /* ─── CTA ─── */
  #cta {
    background: var(--dark);
    padding: 100px 5%; text-align: center;
    position: relative; overflow: hidden;
  }
  #cta::before {
    content: '';
    position: absolute; top: -100px; left: 50%; transform: translateX(-50%);
    width: 600px; height: 600px;
    background: radial-gradient(circle, rgba(20,184,166,0.12) 0%, transparent 70%);
    border-radius: 50%; pointer-events: none;
  }
  .cta-inner { max-width: 640px; margin: 0 auto; position: relative; z-index: 1; }
  .cta-tag {
    display: inline-block; font-family: 'Sora', sans-serif;
    font-size: 0.72rem; font-weight: 700; text-transform: uppercase;
    letter-spacing: 0.1em; color: var(--teal-light);
    background: rgba(20,184,166,0.1);
    padding: 5px 12px; border-radius: 100px; margin-bottom: 20px;
  }
  .cta-title {
    font-size: clamp(2rem, 4vw, 3rem); font-weight: 800;
    color: white; margin-bottom: 18px;
  }
  .cta-sub { color: rgba(255,255,255,0.6); font-size: 1.05rem; margin-bottom: 40px; font-weight: 300; }
  .cta-actions { display: flex; align-items: center; justify-content: center; gap: 14px; flex-wrap: wrap; }
  .btn-white { background: white; color: var(--dark); }
  .btn-white:hover { background: #f5f5f5; transform: translateY(-1px); box-shadow: 0 8px 24px rgba(255,255,255,0.15); }

  .cta-reassurance {
    display: flex; align-items: center; justify-content: center; gap: 24px;
    margin-top: 32px; flex-wrap: wrap;
  }
  .reassurance-item {
    display: flex; align-items: center; gap: 7px;
    font-size: 0.82rem; color: rgba(255,255,255,0.5);
  }
  .reassurance-item svg { color: var(--teal-light); }

  /* ─── FOOTER ─── */
  footer {
    background: #0A0A0A; padding: 60px 5% 32px;
  }
  .footer-inner { max-width: 1160px; margin: 0 auto; }
  .footer-top {
    display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 48px; padding-bottom: 48px;
    border-bottom: 1px solid rgba(255,255,255,0.08);
    margin-bottom: 32px;
  }
  .footer-brand p { color: rgba(255,255,255,0.45); font-size: 0.88rem; line-height: 1.7; margin-top: 14px; font-weight: 300; max-width: 260px; }
  .footer-logo {
    display: flex;
    align-items: center;
    overflow: visible;
    max-height: none;
  }
  .footer-logo-img {
    height: 64px;
    width: auto;
    display: block;
    max-height: none;
    max-width: none;
    opacity: 1;
  }
  .footer-col-title {
    font-family: 'Sora', sans-serif; font-size: 0.82rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.08em;
    color: rgba(255,255,255,0.5); margin-bottom: 16px;
  }
  .footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }
  .footer-col a { color: rgba(255,255,255,0.7); text-decoration: none; font-size: 0.88rem; transition: color 0.2s; }
  .footer-col a:hover { color: var(--teal-light); }
  .footer-bottom {
    display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 16px;
  }
  .footer-copy { color: rgba(255,255,255,0.3); font-size: 0.82rem; }
  .footer-phone { color: rgba(255,255,255,0.5); font-size: 0.88rem; }

  /* ─── SCROLL ANIMATIONS ─── */
  .fade-up {
    opacity: 0; transform: translateY(28px);
    transition: opacity 0.6s ease, transform 0.6s ease;
  }
  .fade-up.visible { opacity: 1; transform: translateY(0); }
  .fade-up:nth-child(2) { transition-delay: 0.1s; }
  .fade-up:nth-child(3) { transition-delay: 0.2s; }
  .fade-up:nth-child(4) { transition-delay: 0.3s; }

  /* ─── RESPONSIVE ─── */
  @media (max-width: 1024px) {
    .steps-grid { grid-template-columns: repeat(2, 1fr); }
    .subjects-grid { grid-template-columns: repeat(2, 1fr); }
    .testimonials-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-top { grid-template-columns: 1fr 1fr; }
  }

  @media (max-width: 768px) {
    section { padding: 72px 5%; }
    .hero-inner { grid-template-columns: 1fr; gap: 48px; }
    .hero-visual { display: none; }
    .problem-grid { grid-template-columns: 1fr; gap: 40px; }
    .results-grid { grid-template-columns: 1fr; }
    .tutor-grid { grid-template-columns: 1fr; gap: 40px; }
    .tutor-photo { aspect-ratio: 3/2; }
    .steps-grid { grid-template-columns: 1fr; }
    .subjects-grid { grid-template-columns: repeat(2, 1fr); }
    .testimonials-grid { grid-template-columns: 1fr; }
    .footer-top { grid-template-columns: 1fr; gap: 32px; }
    .nav-links { display: none; }
    .hamburger { display: flex; }
    .tutor-credentials { grid-template-columns: 1fr; }
    .nav-logo-img { height: 36px; max-height: none; }
    .footer-logo-img { height: 52px; max-height: none; }
  }

  @media (max-width: 480px) {
    .subjects-grid { grid-template-columns: 1fr; }
    .hero-actions { flex-direction: column; align-items: flex-start; }
    .cta-actions { flex-direction: column; }
    .stat-row { grid-template-columns: 1fr; }
  }
  /* ─── BOOKING FORM ─── */
  #booking { background: var(--bg-alt); }
  .booking-grid {
    display: grid; grid-template-columns: 1fr 1fr;
    gap: 64px; align-items: start;
  }
  .booking-form {
    background: white; border: 1px solid var(--border);
    border-radius: var(--radius); padding: 40px;
  }
  .form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-bottom: 16px; }
  .form-group { display: flex; flex-direction: column; gap: 6px; margin-bottom: 16px; }
  .form-group label {
    font-family: 'Sora', sans-serif; font-size: 0.82rem;
    font-weight: 600; color: var(--dark);
  }
  .form-group input,
  .form-group select,
  .form-group textarea {
    padding: 12px 14px; border: 1.5px solid var(--border);
    border-radius: var(--radius-sm); font-family: 'DM Sans', sans-serif;
    font-size: 0.95rem; color: var(--dark);
    background: white; transition: border-color 0.2s;
    outline: none; width: 100%;
  }
  .form-group input:focus,
  .form-group select:focus,
  .form-group textarea:focus { border-color: var(--teal); }
  .form-group textarea { resize: vertical; min-height: 100px; }
  .form-submit { width: 100%; margin-top: 8px; justify-content: center; }
  .form-note { font-size: 0.8rem; color: var(--soft); text-align: center; margin-top: 12px; }
  .booking-info { display: flex; flex-direction: column; gap: 24px; }
  .booking-info-item {
    display: flex; align-items: flex-start; gap: 16px;
    padding: 20px; background: white;
    border: 1px solid var(--border); border-radius: var(--radius-sm);
  }
  .booking-info-icon {
    width: 44px; height: 44px; border-radius: 10px;
    background: var(--teal-bg); display: flex;
    align-items: center; justify-content: center;
    font-size: 1.2rem; flex-shrink: 0;
  }
  .booking-info-title {
    font-family: 'Sora', sans-serif; font-size: 0.95rem;
    font-weight: 700; color: var(--dark); margin-bottom: 4px;
  }
  .booking-info-desc { font-size: 0.88rem; color: var(--soft); line-height: 1.6; }
  .form-success {
    display: none; text-align: center; padding: 40px 20px;
  }
  .form-success-icon {
    width: 56px; height: 56px; border-radius: 50%;
    background: var(--teal); color: white;
    display: flex; align-items: center; justify-content: center;
    font-size: 1.4rem; margin: 0 auto 16px;
  }
  .form-success h3 {
    font-family: 'Sora', sans-serif; font-size: 1.3rem;
    font-weight: 700; color: var(--dark); margin-bottom: 8px;
  }
  .form-success p { font-size: 0.95rem; color: var(--soft); }
  @media (max-width: 768px) {
    .booking-grid { grid-template-columns: 1fr; gap: 32px; }
    .form-row { grid-template-columns: 1fr; }
    .booking-form { padding: 24px; }
  }


/* =====================================================================
   Cross-template scoping corrections (auto-generated during merge)
   These resolve the small number of genuine style differences between
   the home page and the topic-page templates, and between hub pages
   using icon vs SVG topic markers. Uses body.page-home (added only to
   index.html) so specificity -- not source order -- guarantees correctness.
   ===================================================================== */

/* Home page needs a taller hero/section rhythm than topic pages */
body.page-home section { padding: 100px 5%; }
body.page-home .section-header { margin-bottom: 56px; }

/* Home nav logo sizing differs slightly (has its own flex-grow/overflow handling) */
body.page-home .nav-logo { flex-grow: 0; overflow: visible; }

/* Footer logo: topic/hub/resources pages use mix-blend-mode; home uses opacity */
body:not(.page-home) .footer-logo-img { mix-blend-mode: screen; }
body.page-home .footer-logo-img { opacity: 1; }

/* Footer top grid: home has an extra column */
body.page-home .footer-top { grid-template-columns: 1.5fr 1fr 1fr 1fr 1fr; }

/* Home white-button hover gets an extra shadow */
body.page-home .btn-white:hover { box-shadow: 0 8px 24px rgba(255,255,255,0.15); }

/* Home hamburger icon animates; topic pages don't need to */
body.page-home .hamburger span { transition: 0.2s; }

/* Hub topic-icon: algebra/resources hubs use emoji icons (font-size),
   statistics hub uses inline SVG icons (line-height) -- both are valid, merge them */
.topic-card .topic-icon { font-size: 1.8rem; line-height: 1; margin-bottom: 14px; display: block; }