:root {
      --ink: #16221f;
      --ink-soft: #34423e;
      --muted: #697570;
      --paper: #f6f4ed;
      --surface: #fffef9;
      --surface-strong: #ffffff;
      --brand: #0b5b56;
      --brand-deep: #07433f;
      --brand-soft: #deefea;
      --accent: #d96e3f;
      --accent-soft: #f7e6dc;
      --yellow: #e8bd5b;
      --yellow-soft: #fbf1d2;
      --sage: #85a99b;
      --line: #d9dfd8;
      --line-dark: #c4cec6;
      --shadow-sm: 0 8px 24px rgba(25, 54, 46, .06);
      --shadow-md: 0 22px 64px rgba(25, 54, 46, .11);
      --radius-sm: 12px;
      --radius-md: 20px;
      --radius-lg: 30px;
      --space-1: 4px;
      --space-2: 8px;
      --space-3: 12px;
      --space-4: 16px;
      --space-5: 20px;
      --space-6: 24px;
      --space-8: 32px;
      --space-10: 40px;
      --space-12: 48px;
      --space-16: 64px;
      --space-20: 80px;
      --max: 1180px;
      --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
      --font-serif: "Songti SC", "STSong", "SimSun", serif;
    }

    * { box-sizing: border-box; }
    html { scroll-behavior: smooth; scroll-padding-top: 96px; }
    body {
      margin: 0;
      color: var(--ink);
      background: var(--paper);
      font-family: var(--font-sans);
      font-size: 16px;
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      text-rendering: optimizeLegibility;
    }
    body.menu-open { overflow: hidden; }
    a { color: inherit; }
    button, input { font: inherit; }
    button { color: inherit; }
    img, svg { display: block; max-width: 100%; }
    ::selection { color: var(--brand-deep); background: #cde5dc; }
    :focus-visible { outline: 3px solid rgba(217, 110, 63, .5); outline-offset: 3px; }

    .skip-link {
      position: fixed;
      top: 12px;
      left: 12px;
      z-index: 1000;
      padding: 10px 16px;
      color: #fff;
      background: var(--brand-deep);
      border-radius: 10px;
      transform: translateY(-160%);
      transition: transform .2s ease;
    }
    .skip-link:focus { transform: translateY(0); }

    .container { width: min(calc(100% - 40px), var(--max)); margin-inline: auto; }
    .section { padding: 104px 0; position: relative; }
    .section--white { background: var(--surface); }
    .section--deep { color: #fff; background: var(--brand-deep); overflow: hidden; }
    .section--deep::before {
      content: "";
      position: absolute;
      width: 560px;
      height: 560px;
      right: -190px;
      top: -260px;
      border: 1px solid rgba(255,255,255,.12);
      border-radius: 50%;
      box-shadow: 0 0 0 70px rgba(255,255,255,.025), 0 0 0 140px rgba(255,255,255,.02);
    }

    .site-header {
      position: fixed;
      inset: 0 0 auto;
      z-index: 100;
      height: 76px;
      background: rgba(246, 244, 237, .88);
      border-bottom: 1px solid transparent;
      backdrop-filter: blur(18px);
      -webkit-backdrop-filter: blur(18px);
      transition: height .25s ease, border-color .25s ease, box-shadow .25s ease;
    }
    .site-header.is-scrolled {
      height: 68px;
      border-color: rgba(11, 91, 86, .12);
      box-shadow: 0 8px 28px rgba(25, 54, 46, .05);
    }
    .nav-wrap { height: 100%; display: flex; align-items: center; justify-content: space-between; gap: 28px; }
    .brand { display: inline-flex; align-items: center; gap: 12px; text-decoration: none; flex: 0 0 auto; }
    .brand-mark { width: 38px; height: 42px; }
    .brand-copy { display: grid; line-height: 1.1; gap: 4px; }
    .brand-copy strong { font-size: 15px; letter-spacing: .04em; }
    .brand-copy span { color: var(--muted); font-size: 10px; letter-spacing: .18em; text-transform: uppercase; }
    .nav-links { display: flex; align-items: center; gap: 6px; margin-left: auto; }
    .nav-links a {
      padding: 10px 14px;
      color: var(--ink-soft);
      font-size: 14px;
      font-weight: 600;
      text-decoration: none;
      border-radius: 10px;
      transition: color .2s ease, background .2s ease;
    }
    .nav-links a:hover, .nav-links a.is-active { color: var(--brand); background: rgba(11, 91, 86, .07); }
    .nav-note {
      display: inline-flex;
      align-items: center;
      gap: 7px;
      padding: 8px 12px;
      color: var(--brand);
      background: var(--brand-soft);
      border-radius: 999px;
      font-size: 12px;
      font-weight: 700;
      white-space: nowrap;
    }
    .nav-note::before { content: ""; width: 7px; height: 7px; background: var(--brand); border-radius: 50%; }
    .menu-toggle {
      display: none;
      width: 44px;
      height: 44px;
      align-items: center;
      justify-content: center;
      border: 0;
      background: transparent;
      border-radius: 12px;
      cursor: pointer;
    }
    .menu-toggle span, .menu-toggle span::before, .menu-toggle span::after {
      width: 20px;
      height: 2px;
      display: block;
      position: relative;
      background: var(--ink);
      border-radius: 2px;
      transition: transform .2s ease, opacity .2s ease;
    }
    .menu-toggle span::before, .menu-toggle span::after { content: ""; position: absolute; left: 0; }
    .menu-toggle span::before { top: -6px; }
    .menu-toggle span::after { top: 6px; }
    .menu-toggle[aria-expanded="true"] span { background: transparent; }
    .menu-toggle[aria-expanded="true"] span::before { top: 0; transform: rotate(45deg); }
    .menu-toggle[aria-expanded="true"] span::after { top: 0; transform: rotate(-45deg); }
    .mobile-menu { display: none; }

    .hero {
      position: relative;
      min-height: 780px;
      padding: 158px 0 96px;
      overflow: hidden;
      background:
        radial-gradient(circle at 83% 23%, rgba(133, 169, 155, .2), transparent 28%),
        radial-gradient(circle at 8% 82%, rgba(232, 189, 91, .14), transparent 24%),
        var(--paper);
    }
    .hero::before {
      content: "";
      position: absolute;
      inset: 0;
      opacity: .32;
      pointer-events: none;
      background-image: radial-gradient(rgba(11, 91, 86, .2) 1px, transparent 1px);
      background-size: 28px 28px;
      mask-image: linear-gradient(to right, transparent, #000 62%, transparent);
    }
    .hero-grid { display: grid; grid-template-columns: minmax(0, 1.08fr) minmax(420px, .92fr); align-items: center; gap: 76px; position: relative; }
    .eyebrow { display: flex; align-items: center; gap: 12px; margin: 0 0 24px; color: var(--brand); font-size: 13px; font-weight: 800; letter-spacing: .16em; }
    .eyebrow::before { content: ""; width: 34px; height: 2px; background: var(--accent); }
    .hero h1 {
      max-width: 700px;
      margin: 0;
      font-family: var(--font-serif);
      font-size: clamp(48px, 6.2vw, 78px);
      font-weight: 700;
      line-height: 1.12;
      letter-spacing: -.055em;
    }
    .hero h1 em { position: relative; color: var(--brand); font-style: normal; white-space: nowrap; }
    .hero h1 em::after {
      content: "";
      position: absolute;
      left: -1%;
      right: -2%;
      bottom: 2px;
      height: 10px;
      z-index: -1;
      background: var(--yellow);
      border-radius: 50%;
      transform: rotate(-1.5deg);
      opacity: .52;
    }
    .hero-lede { max-width: 640px; margin: 28px 0 0; color: var(--ink-soft); font-size: 18px; line-height: 1.9; }
    .hero-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 14px; margin-top: 34px; }
    .button {
      min-height: 48px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 10px;
      padding: 11px 20px;
      border: 1px solid transparent;
      border-radius: 14px;
      font-size: 14px;
      font-weight: 750;
      text-decoration: none;
      cursor: pointer;
      transition: transform .2s ease, box-shadow .2s ease, background .2s ease, border-color .2s ease;
    }
    .button:hover { transform: translateY(-2px); }
    .button--primary { color: #fff; background: var(--brand); box-shadow: 0 12px 26px rgba(11, 91, 86, .2); }
    .button--primary:hover { background: var(--brand-deep); box-shadow: 0 15px 34px rgba(11, 91, 86, .24); }
    .button--secondary { color: var(--ink); background: rgba(255,255,255,.55); border-color: var(--line-dark); }
    .button--secondary:hover { background: #fff; border-color: var(--brand); }
    .button svg { width: 18px; height: 18px; }
    .hero-meta { display: flex; flex-wrap: wrap; gap: 22px; margin-top: 30px; color: var(--muted); font-size: 12px; }
    .hero-meta span { display: inline-flex; align-items: center; gap: 8px; }
    .hero-meta i { width: 6px; height: 6px; display: block; background: var(--accent); border-radius: 50%; }

    .lab-card {
      position: relative;
      min-height: 474px;
      padding: 28px;
      color: #eaf4f0;
      background: var(--brand-deep);
      border: 1px solid rgba(255,255,255,.12);
      border-radius: 34px;
      box-shadow: var(--shadow-md);
      overflow: hidden;
      transform: rotate(1.2deg);
    }
    .lab-card::before {
      content: "";
      position: absolute;
      width: 360px;
      height: 360px;
      right: -120px;
      bottom: -160px;
      border: 1px solid rgba(255,255,255,.12);
      border-radius: 50%;
      box-shadow: 0 0 0 52px rgba(255,255,255,.025), 0 0 0 104px rgba(255,255,255,.018);
    }
    .lab-card-top { display: flex; align-items: center; justify-content: space-between; position: relative; }
    .lab-card-top span { color: rgba(255,255,255,.58); font-size: 11px; font-weight: 800; letter-spacing: .16em; }
    .periodic-tile {
      width: 74px;
      height: 82px;
      padding: 8px 10px;
      display: grid;
      grid-template-rows: auto 1fr auto;
      background: #f3e9b9;
      color: var(--brand-deep);
      border-radius: 5px;
      box-shadow: 0 10px 28px rgba(0,0,0,.18);
    }
    .periodic-tile small { font-size: 9px; line-height: 1; }
    .periodic-tile strong { align-self: center; font-family: var(--font-serif); font-size: 34px; line-height: 1; text-align: center; }
    .periodic-tile b { font-size: 8px; letter-spacing: .1em; text-align: center; }
    .lab-label { position: relative; margin-top: 38px; color: #a8c9be; font-size: 12px; font-weight: 800; letter-spacing: .15em; }
    .equation { position: relative; margin-top: 13px; font-family: var(--font-serif); font-size: clamp(27px, 3.2vw, 38px); font-weight: 700; line-height: 1.45; }
    .equation .plus { color: var(--yellow); font-family: var(--font-sans); font-weight: 400; }
    .equation .arrow { display: inline-block; margin: 0 4px; color: #8bc2b3; transform: translateY(-2px); }
    .lab-divider { position: relative; height: 1px; margin: 26px 0 22px; background: rgba(255,255,255,.14); }
    .variables { position: relative; display: grid; gap: 12px; }
    .variable { display: grid; grid-template-columns: 58px 1fr auto; align-items: center; gap: 12px; font-size: 12px; }
    .variable code { color: var(--yellow); font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 11px; }
    .variable .bar { height: 5px; background: rgba(255,255,255,.12); border-radius: 99px; overflow: hidden; }
    .variable .bar i { display: block; height: 100%; background: #8bc2b3; border-radius: inherit; }
    .variable b { color: rgba(255,255,255,.72); font-size: 10px; font-weight: 600; }
    .teacher-note {
      position: absolute;
      right: 24px;
      bottom: 22px;
      padding: 9px 13px;
      color: var(--brand-deep);
      background: var(--yellow-soft);
      border-radius: 4px;
      font-family: var(--font-serif);
      font-size: 12px;
      transform: rotate(-3deg);
      box-shadow: 0 6px 18px rgba(0,0,0,.15);
    }
    .molecule { position: absolute; width: 120px; height: 120px; top: 45px; right: 105px; opacity: .28; }

    .source-banner { position: relative; z-index: 2; margin-top: -34px; }
    .source-inner {
      display: grid;
      grid-template-columns: auto 1fr auto;
      align-items: center;
      gap: 20px;
      padding: 20px 24px;
      background: var(--surface-strong);
      border: 1px solid var(--line);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
    }
    .source-icon { width: 42px; height: 42px; display: grid; place-items: center; color: var(--accent); background: var(--accent-soft); border-radius: 12px; }
    .source-icon svg { width: 21px; height: 21px; }
    .source-copy strong { display: block; margin-bottom: 2px; font-size: 14px; }
    .source-copy p { margin: 0; color: var(--muted); font-size: 13px; line-height: 1.7; }
    .source-tag { padding: 6px 10px; color: var(--accent); background: var(--accent-soft); border-radius: 999px; font-size: 11px; font-weight: 800; white-space: nowrap; }

    .section-heading { display: grid; grid-template-columns: auto 1fr; align-items: start; gap: 24px; margin-bottom: 44px; }
    .chapter-tile {
      width: 62px;
      min-height: 70px;
      padding: 9px;
      display: grid;
      grid-template-rows: auto 1fr auto;
      color: var(--brand);
      background: var(--brand-soft);
      border: 1px solid rgba(11, 91, 86, .12);
      border-radius: 8px;
    }
    .chapter-tile span { font-size: 9px; font-weight: 800; line-height: 1; }
    .chapter-tile strong { align-self: center; font-family: var(--font-serif); font-size: 28px; line-height: 1; text-align: center; }
    .chapter-tile small { color: var(--muted); font-size: 7px; letter-spacing: .08em; text-align: center; }
    .section-kicker { margin: 0 0 8px; color: var(--accent); font-size: 11px; font-weight: 800; letter-spacing: .18em; text-transform: uppercase; }
    .section-heading h2 { margin: 0; font-family: var(--font-serif); font-size: clamp(34px, 4vw, 50px); line-height: 1.25; letter-spacing: -.035em; }
    .section-heading p:last-child { max-width: 680px; margin: 12px 0 0; color: var(--muted); font-size: 15px; }

    .quick-layout { display: grid; grid-template-columns: minmax(280px, .75fr) minmax(0, 1.25fr); gap: 32px; align-items: start; }
    .search-panel {
      position: sticky;
      top: 92px;
      padding: 28px;
      color: #fff;
      background: var(--brand);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-md);
    }
    .search-panel h3 { margin: 0; font-family: var(--font-serif); font-size: 28px; }
    .search-panel > p { margin: 8px 0 20px; color: rgba(255,255,255,.72); font-size: 13px; }
    .search-field { position: relative; }
    .search-field svg { position: absolute; left: 14px; top: 50%; width: 18px; height: 18px; color: var(--muted); transform: translateY(-50%); pointer-events: none; }
    .search-field input {
      width: 100%;
      height: 50px;
      padding: 0 42px;
      color: var(--ink);
      background: #fff;
      border: 0;
      border-radius: 13px;
      outline: none;
    }
    .search-field input:focus { box-shadow: 0 0 0 4px rgba(232, 189, 91, .4); }
    .search-clear {
      position: absolute;
      right: 7px;
      top: 7px;
      width: 36px;
      height: 36px;
      display: none;
      place-items: center;
      padding: 0;
      color: var(--muted);
      background: transparent;
      border: 0;
      border-radius: 9px;
      cursor: pointer;
    }
    .search-clear.is-visible { display: grid; }
    .search-suggestions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 14px; }
    .search-suggestions button {
      padding: 7px 10px;
      color: rgba(255,255,255,.82);
      background: rgba(255,255,255,.09);
      border: 1px solid rgba(255,255,255,.16);
      border-radius: 999px;
      font-size: 11px;
      cursor: pointer;
      transition: background .2s ease;
    }
    .search-suggestions button:hover { color: #fff; background: rgba(255,255,255,.16); }
    .search-results { display: none; margin-top: 14px; padding: 8px; color: var(--ink); background: #fff; border-radius: 14px; box-shadow: 0 15px 35px rgba(0,0,0,.16); }
    .search-results.is-visible { display: grid; }
    .search-result { display: grid; gap: 2px; padding: 10px 11px; text-decoration: none; border-radius: 9px; }
    .search-result:hover { background: var(--brand-soft); }
    .search-result strong { color: var(--brand); font-size: 12px; }
    .search-result span { color: var(--muted); font-size: 10px; line-height: 1.5; }
    .search-empty { margin: 0; padding: 12px; color: var(--muted); font-size: 12px; text-align: center; }
    .search-footnote { display: flex; align-items: center; gap: 8px; margin-top: 20px; color: rgba(255,255,255,.62); font-size: 10px; }
    .search-footnote svg { width: 15px; height: 15px; }

    .quick-cards { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
    .quick-card {
      min-height: 210px;
      padding: 24px;
      position: relative;
      background: var(--surface-strong);
      border: 1px solid var(--line);
      border-radius: var(--radius-md);
      overflow: hidden;
      transition: transform .22s ease, box-shadow .22s ease, border-color .22s ease;
    }
    .quick-card:hover { transform: translateY(-4px); border-color: rgba(11,91,86,.3); box-shadow: var(--shadow-sm); }
    .quick-card:first-child { grid-column: span 2; min-height: 190px; background: var(--yellow-soft); border-color: #ead99c; }
    .quick-num { color: var(--accent); font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 11px; font-weight: 700; }
    .quick-card h3 { margin: 24px 0 7px; font-size: 18px; line-height: 1.45; }
    .quick-card p { margin: 0; color: var(--muted); font-size: 13px; line-height: 1.75; }
    .quick-card:first-child h3 { margin-top: 18px; font-family: var(--font-serif); font-size: 23px; }
    .address-row { display: grid; grid-template-columns: 1fr auto; align-items: end; gap: 18px; }
    .copy-button {
      min-width: 94px;
      min-height: 42px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 7px;
      padding: 8px 13px;
      color: var(--brand);
      background: rgba(255,255,255,.66);
      border: 1px solid rgba(11,91,86,.2);
      border-radius: 11px;
      font-size: 12px;
      font-weight: 750;
      cursor: pointer;
    }
    .copy-button:hover { background: #fff; }
    .copy-button svg { width: 15px; height: 15px; }
    .card-tag { position: absolute; top: 20px; right: 20px; padding: 5px 9px; color: var(--brand); background: var(--brand-soft); border-radius: 999px; font-size: 10px; font-weight: 750; }
    .card-tag--check { color: var(--accent); background: var(--accent-soft); }

    .bento { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 18px; }
    .info-card {
      grid-column: span 4;
      padding: 28px;
      background: var(--surface-strong);
      border: 1px solid var(--line);
      border-radius: var(--radius-md);
      box-shadow: 0 1px 0 rgba(255,255,255,.7) inset;
    }
    .info-card--wide { grid-column: span 8; }
    .info-card--full { grid-column: 1 / -1; }
    .info-card--tint { background: var(--brand-soft); border-color: rgba(11,91,86,.14); }
    .info-card--warm { background: var(--accent-soft); border-color: rgba(217,110,63,.14); }
    .info-icon { width: 44px; height: 44px; display: grid; place-items: center; margin-bottom: 22px; color: var(--brand); background: var(--brand-soft); border-radius: 13px; }
    .info-card--tint .info-icon { background: rgba(255,255,255,.62); }
    .info-card--warm .info-icon { color: var(--accent); background: rgba(255,255,255,.64); }
    .info-icon svg { width: 22px; height: 22px; }
    .info-card h3 { margin: 0 0 11px; font-size: 18px; line-height: 1.45; }
    .info-card p { margin: 0; color: var(--muted); font-size: 13px; }
    .clean-list { display: grid; gap: 12px; margin: 18px 0 0; padding: 0; list-style: none; }
    .clean-list li { display: grid; grid-template-columns: 17px 1fr; gap: 9px; color: var(--ink-soft); font-size: 13px; }
    .clean-list li::before { content: ""; width: 7px; height: 7px; margin-top: 8px; background: var(--accent); border-radius: 50%; box-shadow: 0 0 0 4px var(--accent-soft); }
    .teacher-callout {
      display: grid;
      grid-template-columns: auto 1fr;
      gap: 18px;
      align-items: start;
      padding: 24px 26px;
      color: #f4faf7;
      background: var(--brand-deep);
      border-radius: var(--radius-md);
    }
    .teacher-callout .chalk { padding: 5px 9px; color: var(--brand-deep); background: var(--yellow); border-radius: 4px; font-size: 10px; font-weight: 800; transform: rotate(-2deg); }
    .teacher-callout h3 { margin: 0 0 6px; font-family: var(--font-serif); font-size: 20px; }
    .teacher-callout p { margin: 0; color: rgba(255,255,255,.7); font-size: 13px; }

    .military-layout { display: grid; grid-template-columns: minmax(0, 1.08fr) minmax(320px, .92fr); gap: 24px; align-items: start; }
    .packing-card { padding: 30px; background: #fff; border: 1px solid var(--line); border-radius: var(--radius-lg); box-shadow: var(--shadow-sm); }
    .packing-head { display: flex; align-items: center; justify-content: space-between; gap: 18px; padding-bottom: 24px; border-bottom: 1px solid var(--line); }
    .packing-head h3 { margin: 0 0 4px; font-family: var(--font-serif); font-size: 25px; }
    .packing-head p { margin: 0; color: var(--muted); font-size: 12px; }
    .progress-ring {
      --progress: 0;
      width: 72px;
      height: 72px;
      display: grid;
      place-items: center;
      flex: 0 0 auto;
      background: conic-gradient(var(--brand) calc(var(--progress) * 1%), var(--brand-soft) 0);
      border-radius: 50%;
      position: relative;
    }
    .progress-ring::before { content: ""; position: absolute; inset: 7px; background: #fff; border-radius: 50%; }
    .progress-ring strong { position: relative; color: var(--brand); font-size: 13px; }
    .check-group { padding-top: 24px; }
    .check-group + .check-group { margin-top: 22px; border-top: 1px dashed var(--line-dark); }
    .check-group-title { display: flex; align-items: center; gap: 8px; margin-bottom: 13px; color: var(--muted); font-size: 11px; font-weight: 800; letter-spacing: .12em; }
    .check-group-title::before { content: ""; width: 18px; height: 2px; background: var(--accent); }
    .check-grid { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 10px; }
    .check-item { position: relative; }
    .check-item input { position: absolute; opacity: 0; pointer-events: none; }
    .check-item label {
      min-height: 46px;
      display: flex;
      align-items: center;
      gap: 10px;
      padding: 10px 12px;
      color: var(--ink-soft);
      background: var(--paper);
      border: 1px solid transparent;
      border-radius: 11px;
      font-size: 12px;
      cursor: pointer;
      transition: background .2s ease, border-color .2s ease, color .2s ease;
    }
    .check-box { width: 18px; height: 18px; display: grid; place-items: center; flex: 0 0 auto; border: 1.5px solid var(--line-dark); border-radius: 5px; background: #fff; }
    .check-box svg { width: 12px; height: 12px; color: #fff; opacity: 0; transform: scale(.5); transition: opacity .16s ease, transform .16s ease; }
    .check-item input:focus-visible + label { outline: 3px solid rgba(217,110,63,.45); outline-offset: 2px; }
    .check-item input:checked + label { color: var(--brand); background: var(--brand-soft); border-color: rgba(11,91,86,.15); }
    .check-item input:checked + label .check-box { background: var(--brand); border-color: var(--brand); }
    .check-item input:checked + label .check-box svg { opacity: 1; transform: scale(1); }
    .packing-foot { display: flex; align-items: center; justify-content: space-between; gap: 18px; margin-top: 24px; padding-top: 18px; border-top: 1px solid var(--line); }
    .packing-foot span { color: var(--muted); font-size: 11px; }
    .text-button { padding: 5px 0; color: var(--brand); background: none; border: 0; border-bottom: 1px solid currentColor; font-size: 11px; font-weight: 750; cursor: pointer; }
    .military-side { display: grid; gap: 18px; }
    .time-card, .uniform-card, .med-card { padding: 26px; background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius-md); }
    .time-card { color: #fff; background: var(--brand); border-color: transparent; }
    .card-eyebrow { margin: 0 0 7px; color: var(--accent); font-size: 10px; font-weight: 850; letter-spacing: .15em; }
    .time-card .card-eyebrow { color: var(--yellow); }
    .time-card h3, .uniform-card h3, .med-card h3 { margin: 0 0 14px; font-family: var(--font-serif); font-size: 22px; }
    .time-track { display: grid; gap: 0; margin-top: 20px; }
    .time-row { display: grid; grid-template-columns: 76px 18px 1fr; gap: 12px; min-height: 64px; }
    .time-row > strong { padding-top: 1px; color: #fff; font-size: 12px; }
    .time-node { position: relative; }
    .time-node::before { content: ""; width: 9px; height: 9px; position: absolute; top: 6px; left: 4px; z-index: 1; background: var(--yellow); border: 3px solid var(--brand); border-radius: 50%; box-shadow: 0 0 0 1px rgba(255,255,255,.32); }
    .time-node::after { content: ""; position: absolute; top: 19px; bottom: -6px; left: 8px; width: 1px; background: rgba(255,255,255,.2); }
    .time-row:last-child .time-node::after { display: none; }
    .time-row p { margin: 0; color: rgba(255,255,255,.67); font-size: 11px; line-height: 1.6; }
    .uniform-card ul, .med-card ul { margin: 0; padding-left: 18px; color: var(--muted); font-size: 12px; }
    .uniform-card li + li, .med-card li + li { margin-top: 8px; }
    .med-card { background: var(--yellow-soft); border-color: #ead99c; }
    .med-card p { margin: 0; color: #74643c; font-size: 12px; }

    .study-grid { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 18px; }
    .study-card { grid-column: span 4; min-height: 280px; padding: 28px; background: rgba(255,255,255,.06); border: 1px solid rgba(255,255,255,.12); border-radius: var(--radius-md); position: relative; overflow: hidden; }
    .study-card--wide { grid-column: span 8; }
    .study-card--accent { color: var(--brand-deep); background: var(--yellow-soft); border-color: transparent; }
    .study-index { color: var(--yellow); font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 11px; }
    .study-card--accent .study-index { color: var(--accent); }
    .study-card h3 { margin: 32px 0 10px; font-family: var(--font-serif); font-size: 23px; }
    .study-card p { margin: 0; color: rgba(255,255,255,.67); font-size: 13px; }
    .study-card--accent p { color: #675f46; }
    .formula {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 9px;
      margin: 22px 0 18px;
      font-family: var(--font-serif);
      font-size: 19px;
      font-weight: 700;
    }
    .formula span { padding: 7px 11px; color: var(--brand-deep); background: rgba(255,255,255,.7); border-radius: 8px; }
    .formula b { color: var(--accent); }
    .verify-note { display: flex; align-items: flex-start; gap: 9px; margin-top: 18px; padding-top: 16px; border-top: 1px solid rgba(255,255,255,.12); color: #adcbc1; font-size: 10px; }
    .study-card--accent .verify-note { color: #7b6c3d; border-top-color: rgba(103,95,70,.18); }
    .verify-note svg { width: 14px; height: 14px; flex: 0 0 auto; margin-top: 2px; }
    .number-pair { display: flex; gap: 12px; margin-top: 24px; }
    .number-box { min-width: 102px; padding: 14px; background: rgba(255,255,255,.08); border-radius: 12px; }
    .number-box strong { display: block; color: var(--yellow); font-family: var(--font-serif); font-size: 28px; line-height: 1; }
    .number-box span { color: rgba(255,255,255,.58); font-size: 9px; }
    .lesson-note { grid-column: 1 / -1; display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 20px; padding: 25px 28px; background: rgba(255,255,255,.07); border: 1px dashed rgba(255,255,255,.25); border-radius: var(--radius-md); }
    .lesson-note .mark { width: 46px; height: 46px; display: grid; place-items: center; color: var(--brand-deep); background: var(--yellow); border-radius: 50%; font-family: var(--font-serif); font-size: 21px; font-weight: 800; }
    .lesson-note h3 { margin: 0 0 4px; font-family: var(--font-serif); font-size: 20px; }
    .lesson-note p { margin: 0; color: rgba(255,255,255,.64); font-size: 12px; }
    .lesson-note b { color: var(--yellow); font-family: var(--font-serif); font-size: 15px; white-space: nowrap; }

    .action-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; }
    .action-card { padding: 25px 22px; background: #fff; border: 1px solid var(--line); border-radius: var(--radius-md); position: relative; }
    .action-card::after { content: ""; position: absolute; top: 41px; left: calc(100% + 1px); width: 16px; border-top: 1px dashed var(--line-dark); }
    .action-card:last-child::after { display: none; }
    .action-day { display: inline-flex; align-items: center; min-height: 28px; padding: 4px 9px; color: var(--brand); background: var(--brand-soft); border-radius: 7px; font-size: 10px; font-weight: 800; }
    .action-card h3 { margin: 24px 0 10px; font-family: var(--font-serif); font-size: 19px; }
    .action-card ul { display: grid; gap: 8px; margin: 0; padding: 0; list-style: none; }
    .action-card li { display: grid; grid-template-columns: 13px 1fr; gap: 8px; color: var(--muted); font-size: 11px; }
    .action-card li::before { content: "✓"; color: var(--accent); font-weight: 800; }

    .final-note {
      display: grid;
      grid-template-columns: minmax(0, 1.2fr) minmax(280px, .8fr);
      gap: 40px;
      align-items: center;
      margin-top: 56px;
      padding: 38px 40px;
      background: var(--yellow-soft);
      border: 1px solid #ead99c;
      border-radius: var(--radius-lg);
    }
    .final-note h3 { margin: 0 0 9px; font-family: var(--font-serif); font-size: 27px; }
    .final-note p { margin: 0; color: #756a49; font-size: 13px; }
    .official-list { display: grid; gap: 8px; padding-left: 24px; border-left: 1px solid #d9c887; }
    .official-list span { display: flex; align-items: center; gap: 9px; color: #675f46; font-size: 12px; }
    .official-list i { width: 6px; height: 6px; background: var(--accent); border-radius: 50%; }

    .site-footer { padding: 36px 0 44px; border-top: 1px solid var(--line); }
    .footer-inner { display: flex; align-items: center; justify-content: space-between; gap: 28px; }
    .footer-brand { display: flex; align-items: center; gap: 12px; }
    .footer-brand svg { width: 34px; height: 38px; }
    .footer-brand strong { display: block; font-size: 13px; }
    .footer-brand span { display: block; color: var(--muted); font-size: 10px; }
    .footer-meta { color: var(--muted); font-size: 10px; text-align: right; }
    .footer-meta p { margin: 0; }
    .footer-meta p + p { margin-top: 3px; }

    .toast {
      position: fixed;
      left: 50%;
      bottom: 28px;
      z-index: 300;
      padding: 11px 16px;
      color: #fff;
      background: var(--ink);
      border-radius: 10px;
      box-shadow: var(--shadow-md);
      font-size: 12px;
      opacity: 0;
      pointer-events: none;
      transform: translate(-50%, 20px);
      transition: opacity .22s ease, transform .22s ease;
    }
    .toast.is-visible { opacity: 1; transform: translate(-50%, 0); }
    .back-top {
      position: fixed;
      right: 22px;
      bottom: 22px;
      z-index: 80;
      width: 44px;
      height: 44px;
      display: grid;
      place-items: center;
      color: #fff;
      background: var(--brand);
      border: 0;
      border-radius: 13px;
      box-shadow: var(--shadow-sm);
      cursor: pointer;
      opacity: 0;
      pointer-events: none;
      transform: translateY(10px);
      transition: opacity .2s ease, transform .2s ease;
    }
    .back-top.is-visible { opacity: 1; pointer-events: auto; transform: translateY(0); }
    .back-top svg { width: 18px; height: 18px; }

    @media (max-width: 980px) {
      .nav-links, .nav-note { display: none; }
      .menu-toggle { display: inline-flex; }
      .mobile-menu {
        position: fixed;
        inset: 76px 0 auto;
        z-index: 99;
        display: grid;
        gap: 6px;
        padding: 18px 20px 24px;
        background: rgba(246,244,237,.98);
        border-bottom: 1px solid var(--line);
        box-shadow: var(--shadow-sm);
        opacity: 0;
        visibility: hidden;
        transform: translateY(-8px);
        transition: opacity .2s ease, transform .2s ease, visibility .2s ease;
      }
      .site-header.is-scrolled + .mobile-menu { top: 68px; }
      .mobile-menu.is-open { opacity: 1; visibility: visible; transform: translateY(0); }
      .mobile-menu a { padding: 13px 12px; text-decoration: none; border-radius: 10px; font-weight: 700; }
      .mobile-menu a:hover { color: var(--brand); background: var(--brand-soft); }
      .hero { min-height: auto; padding-top: 132px; }
      .hero-grid { grid-template-columns: 1fr; gap: 58px; }
      .hero-copy { max-width: 760px; }
      .lab-card { width: min(100%, 620px); min-height: 430px; margin-inline: auto; }
      .quick-layout { grid-template-columns: 1fr; }
      .search-panel { position: static; }
      .info-card, .info-card--wide { grid-column: span 6; }
      .military-layout { grid-template-columns: 1fr; }
      .military-side { grid-template-columns: repeat(2, minmax(0,1fr)); }
      .time-card { grid-row: span 2; }
      .study-card, .study-card--wide { grid-column: span 6; }
      .action-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
      .action-card:nth-child(2)::after { display: none; }
      .final-note { grid-template-columns: 1fr; gap: 24px; }
      .official-list { padding: 20px 0 0; border-left: 0; border-top: 1px solid #d9c887; }
    }

    @media (max-width: 700px) {
      .container { width: min(calc(100% - 28px), var(--max)); }
      .section { padding: 76px 0; }
      .site-header { height: 68px; }
      .brand-copy span { display: none; }
      .mobile-menu { top: 68px; }
      .hero { padding: 112px 0 72px; }
      .hero::before { display: none; }
      .hero h1 { font-size: clamp(41px, 12vw, 58px); letter-spacing: -.06em; }
      .hero-lede { margin-top: 22px; font-size: 16px; line-height: 1.8; }
      .hero-actions { align-items: stretch; }
      .hero-actions .button { flex: 1 1 180px; }
      .hero-meta { gap: 10px 18px; }
      .lab-card { min-height: 398px; padding: 22px; border-radius: 26px; transform: none; }
      .periodic-tile { width: 64px; height: 71px; }
      .molecule { width: 92px; right: 88px; }
      .lab-label { margin-top: 28px; }
      .equation { font-size: 25px; }
      .variable { grid-template-columns: 50px 1fr auto; gap: 9px; }
      .teacher-note { right: 17px; bottom: 16px; }
      .source-banner { margin-top: -22px; }
      .source-inner { grid-template-columns: auto 1fr; padding: 17px; }
      .source-tag { display: none; }
      .section-heading { grid-template-columns: 52px 1fr; gap: 16px; margin-bottom: 32px; }
      .chapter-tile { width: 52px; min-height: 60px; }
      .chapter-tile strong { font-size: 24px; }
      .section-heading h2 { font-size: 33px; }
      .section-heading p:last-child { font-size: 13px; }
      .search-panel { padding: 23px; border-radius: 22px; }
      .quick-cards { grid-template-columns: 1fr; }
      .quick-card:first-child { grid-column: auto; }
      .address-row { grid-template-columns: 1fr; align-items: start; }
      .copy-button { justify-self: start; }
      .info-card, .info-card--wide, .info-card--full { grid-column: 1 / -1; }
      .info-card { padding: 24px; }
      .teacher-callout { grid-template-columns: 1fr; }
      .teacher-callout .chalk { justify-self: start; }
      .packing-card { padding: 23px 18px; border-radius: 24px; }
      .progress-ring { width: 66px; height: 66px; }
      .check-grid { grid-template-columns: 1fr; }
      .military-side { grid-template-columns: 1fr; }
      .time-card { grid-row: auto; }
      .study-card, .study-card--wide { grid-column: 1 / -1; min-height: auto; }
      .lesson-note { grid-template-columns: auto 1fr; }
      .lesson-note b { grid-column: 2; white-space: normal; }
      .action-grid { grid-template-columns: 1fr; }
      .action-card::after { display: none; }
      .final-note { margin-top: 40px; padding: 28px 23px; border-radius: 22px; }
      .footer-inner { align-items: flex-start; flex-direction: column; }
      .footer-meta { text-align: left; }
      .back-top { right: 14px; bottom: 14px; }
    }

    @media (prefers-reduced-motion: reduce) {
      html { scroll-behavior: auto; }
      *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
    }