:root {
      --paper: #f3efe5;
      --paper-2: #fffdf7;
      --paper-3: #ebe4d6;
      --ink: #19211e;
      --muted: #66706b;
      --line: #d9d0c0;
      --forest: #16231f;
      --forest-2: #22352e;
      --accent: #d65f3f;
      --accent-2: #efb85c;
      --code: #111a17;
      --code-ink: #e8efe9;
      --shadow: 0 16px 45px rgba(42, 35, 25, .09);
      --radius: 20px;
      --max: 1180px;
    }

    [data-theme="dark"] {
      --paper: #101714;
      --paper-2: #17211d;
      --paper-3: #202d27;
      --ink: #e9eee9;
      --muted: #a8b4ad;
      --line: #334139;
      --forest: #0c1310;
      --forest-2: #1d3028;
      --accent: #ef7857;
      --accent-2: #f1bd67;
      --code: #09100d;
      --code-ink: #e8efe9;
      --shadow: 0 18px 50px rgba(0, 0, 0, .22);
    }

    * { box-sizing: border-box; }
    html { scroll-behavior: smooth; scroll-padding-top: 28px; }
    body {
      margin: 0;
      color: var(--ink);
      background:
        radial-gradient(circle at 8% 4%, rgba(239, 184, 92, .13), transparent 24rem),
        var(--paper);
      font-family: "Microsoft YaHei UI", "PingFang SC", "Noto Sans CJK SC", system-ui, sans-serif;
      line-height: 1.72;
      transition: color .25s ease, background-color .25s ease;
    }

    button, input { font: inherit; }
    button { cursor: pointer; }
    a { color: inherit; }
    code, pre { font-family: "Cascadia Code", "SFMono-Regular", Consolas, monospace; }
    ::selection { color: #fff; background: var(--accent); }

    .progress {
      position: fixed;
      inset: 0 0 auto 0;
      z-index: 100;
      height: 4px;
      transform: scaleX(0);
      transform-origin: left;
      background: linear-gradient(90deg, var(--accent), var(--accent-2));
    }

    .utility {
      position: absolute;
      top: 22px;
      right: max(22px, calc((100% - var(--max)) / 2));
      z-index: 5;
      display: flex;
      gap: 8px;
    }

    .icon-button {
      display: inline-grid;
      width: 42px;
      height: 42px;
      place-items: center;
      color: #f9f6ed;
      background: rgba(255, 255, 255, .08);
      border: 1px solid rgba(255, 255, 255, .16);
      border-radius: 50%;
      transition: transform .2s ease, background .2s ease;
    }
    .icon-button:hover { transform: translateY(-2px); background: rgba(255, 255, 255, .16); }
    .icon-button:focus-visible, .copy:focus-visible, .side-group-toggle:focus-visible,
    .detail-card-tabs button:focus-visible, .nav-pattern-tab:focus-visible, a:focus-visible {
      outline: 3px solid var(--accent-2);
      outline-offset: 3px;
    }

    .masthead {
      position: relative;
      overflow: hidden;
      min-height: 390px;
      color: #f7f3e9;
      background: var(--forest);
    }
    .masthead::before {
      content: "";
      position: absolute;
      width: 520px;
      height: 520px;
      top: -290px;
      right: 6%;
      border: 1px solid rgba(239, 184, 92, .32);
      border-radius: 50%;
      box-shadow: 0 0 0 62px rgba(239, 184, 92, .05), 0 0 0 125px rgba(239, 184, 92, .035);
    }
    .masthead::after {
      content: "写卡";
      position: absolute;
      right: 8%;
      bottom: -82px;
      color: rgba(255, 255, 255, .035);
      font-family: SimSun, serif;
      font-size: clamp(150px, 24vw, 310px);
      font-weight: 900;
      line-height: 1;
      letter-spacing: -.1em;
      pointer-events: none;
    }

    .hero {
      position: relative;
      z-index: 1;
      width: min(calc(100% - 44px), var(--max));
      margin: 0 auto;
      padding: 82px 0 64px;
    }
    .eyebrow {
      display: flex;
      align-items: center;
      gap: 12px;
      margin: 0 0 20px;
      color: var(--accent-2);
      font-size: 12px;
      font-weight: 800;
      letter-spacing: .18em;
      text-transform: uppercase;
    }
    .eyebrow::before { content: ""; width: 42px; height: 2px; background: currentColor; }
    h1 {
      margin: 0;
      font-family: SimSun, "Songti SC", serif;
      font-size: clamp(56px, 9vw, 112px);
      line-height: .98;
      letter-spacing: -.07em;
    }
    .hero-lead {
      max-width: 650px;
      margin: 24px 0 0;
      color: #c8d2cd;
      font-size: clamp(16px, 2vw, 20px);
    }
    .hero-meta {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      margin-top: 28px;
    }
    .hero-meta span {
      padding: 7px 12px;
      color: #e8eee9;
      background: rgba(255, 255, 255, .07);
      border: 1px solid rgba(255, 255, 255, .11);
      border-radius: 99px;
      font-size: 13px;
    }

    .layout {
      display: grid;
      grid-template-columns: 255px minmax(0, 1fr);
      gap: 38px;
      width: min(calc(100% - 44px), var(--max));
      margin: 40px auto 80px;
    }

    .sidebar { align-self: start; position: sticky; top: 24px; }
    .side-panel {
      padding: 18px;
      max-height: calc(100vh - 48px);
      overflow-y: auto;
      color: #e7eee9;
      background: var(--forest);
      border-radius: var(--radius);
      box-shadow: var(--shadow);
    }
    .side-title {
      margin: 4px 8px 13px;
      color: #93a59c;
      font-size: 11px;
      font-weight: 800;
      letter-spacing: .16em;
      text-transform: uppercase;
    }
    .side-nav { display: grid; gap: 4px; }
    .side-nav a {
      display: grid;
      grid-template-columns: 28px 1fr;
      gap: 9px;
      align-items: center;
      padding: 10px;
      color: #adbbb4;
      border-radius: 11px;
      font-size: 14px;
      text-decoration: none;
      transition: color .2s, background .2s, transform .2s;
    }
    .side-group { display: grid; gap: 4px; }
    .side-group-toggle {
      display: grid;
      grid-template-columns: 28px 1fr 18px;
      gap: 9px;
      width: 100%;
      align-items: center;
      padding: 10px;
      color: #adbbb4;
      background: transparent;
      border: 0;
      border-radius: 11px;
      font-size: 14px;
      text-align: left;
      transition: color .2s, background .2s, transform .2s;
    }
    .side-group-toggle b {
      display: grid;
      width: 26px;
      height: 26px;
      place-items: center;
      border: 1px solid rgba(255, 255, 255, .18);
      border-radius: 8px;
      font-size: 11px;
    }
    .side-group-toggle i { font-style: normal; transition: transform .2s; }
    .side-group-toggle[aria-expanded="true"] i { transform: rotate(180deg); }
    .side-subnav { display: grid; gap: 4px; }
    .side-nav a:hover, .side-group-toggle:hover { color: #fff; background: rgba(255, 255, 255, .07); transform: translateX(2px); }
    .side-nav a.active { color: #fff; background: var(--accent); }
    .side-group-toggle.active { color: #fff; background: var(--accent); }
    .side-nav a.sub-link { margin-left: 18px; padding-block: 8px; color: #93a59c; font-size: 13px; }
    .side-nav a.sub-link b { width: 30px; border-style: dashed; font-size: 10px; }
    .side-nav b {
      display: grid;
      width: 26px;
      height: 26px;
      place-items: center;
      border: 1px solid rgba(255, 255, 255, .18);
      border-radius: 8px;
      font-size: 11px;
    }
    .side-tip {
      margin: 16px 0 0;
      padding: 16px;
      color: var(--muted);
      background: var(--paper-2);
      border: 1px solid var(--line);
      border-radius: 16px;
      font-size: 13px;
    }
    .side-tip strong { display: block; margin-bottom: 4px; color: var(--ink); }

    .content { min-width: 0; }
    .intro-strip {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1px;
      overflow: hidden;
      margin-bottom: 26px;
      background: var(--line);
      border: 1px solid var(--line);
      border-radius: var(--radius);
      box-shadow: var(--shadow);
    }
    .intro-strip div { padding: 20px; background: var(--paper-2); }
    .intro-strip strong { display: block; margin-bottom: 3px; font-size: 17px; }
    .intro-strip span { color: var(--muted); font-size: 13px; }

    .chapter {
      scroll-margin-top: 24px;
      margin-bottom: 28px;
      padding: clamp(24px, 4vw, 44px);
      background: var(--paper-2);
      border: 1px solid var(--line);
      border-radius: var(--radius);
      box-shadow: var(--shadow);
    }
    .chapter:not([hidden]) { animation: detail-card-in .24s ease both; }
    .chapter-head {
      display: grid;
      grid-template-columns: 62px 1fr;
      gap: 18px;
      align-items: start;
      margin-bottom: 30px;
    }
    .chapter-no {
      display: grid;
      width: 62px;
      height: 62px;
      place-items: center;
      color: #fff;
      background: var(--accent);
      border-radius: 18px 18px 18px 5px;
      font-family: Georgia, serif;
      font-size: 24px;
      font-weight: 700;
    }
    .kicker {
      margin: 0 0 5px;
      color: var(--accent);
      font-size: 11px;
      font-weight: 900;
      letter-spacing: .16em;
      text-transform: uppercase;
    }
    h2, h3, h4 { line-height: 1.35; }
    h2 { margin: 0; font-size: clamp(26px, 4vw, 38px); letter-spacing: -.04em; }
    .chapter-summary { max-width: 700px; margin: 8px 0 0; color: var(--muted); }
    h3 { margin: 34px 0 13px; font-size: 21px; }
    h3:first-child { margin-top: 0; }
    h4 { margin: 18px 0 6px; font-size: 16px; }
    p { margin: 0 0 14px; }

    .cards {
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 13px;
      margin: 16px 0 22px;
    }
    .mini-card {
      padding: 18px;
      background: var(--paper);
      border: 1px solid var(--line);
      border-radius: 15px;
    }
    .mini-card .tag {
      display: inline-block;
      margin-bottom: 9px;
      padding: 3px 8px;
      color: var(--accent);
      background: color-mix(in srgb, var(--accent) 11%, transparent);
      border-radius: 6px;
      font-size: 11px;
      font-weight: 900;
      letter-spacing: .08em;
    }
    .mini-card h4 { margin: 0 0 5px; }
    .mini-card p { margin: 0; color: var(--muted); font-size: 14px; }

    .callout {
      position: relative;
      margin: 22px 0;
      padding: 17px 19px 17px 52px;
      background: color-mix(in srgb, var(--accent-2) 14%, var(--paper-2));
      border: 1px solid color-mix(in srgb, var(--accent-2) 55%, var(--line));
      border-radius: 14px;
    }
    .callout::before {
      content: "✦";
      position: absolute;
      left: 19px;
      top: 16px;
      color: #ad6b12;
      font-size: 20px;
    }
    .callout strong { color: color-mix(in srgb, var(--accent) 78%, var(--ink)); }

    .flow {
      display: grid;
      grid-template-columns: repeat(5, 1fr);
      gap: 9px;
      margin: 18px 0 26px;
      counter-reset: flow;
    }
    .flow div {
      position: relative;
      min-height: 94px;
      padding: 16px 11px 12px;
      text-align: center;
      background: var(--paper);
      border: 1px solid var(--line);
      border-radius: 13px;
      font-size: 13px;
    }
    .flow div::before {
      counter-increment: flow;
      content: counter(flow, decimal-leading-zero);
      display: block;
      margin-bottom: 5px;
      color: var(--accent);
      font: 800 11px/1 system-ui, sans-serif;
      letter-spacing: .1em;
    }

    .table-wrap { overflow-x: auto; margin: 16px 0 24px; border: 1px solid var(--line); border-radius: 14px; }
    table { width: 100%; min-width: 640px; border-collapse: collapse; background: var(--paper-2); font-size: 14px; }
    th, td { padding: 13px 15px; text-align: left; vertical-align: top; border-bottom: 1px solid var(--line); }
    th { color: var(--muted); background: var(--paper); font-size: 12px; letter-spacing: .04em; }
    tr:last-child td { border-bottom: 0; }
    td:first-child { color: var(--accent); font-weight: 800; white-space: nowrap; }

    .code-card {
      overflow: hidden;
      margin: 16px 0 24px;
      color: var(--code-ink);
      background: var(--code);
      border: 1px solid rgba(255, 255, 255, .08);
      border-radius: 15px;
    }
    .code-head {
      display: flex;
      align-items: center;
      justify-content: space-between;
      min-height: 45px;
      padding: 8px 10px 8px 16px;
      color: #9fb0a7;
      background: rgba(255, 255, 255, .035);
      border-bottom: 1px solid rgba(255, 255, 255, .08);
      font-size: 12px;
      font-weight: 800;
      letter-spacing: .08em;
      text-transform: uppercase;
    }
    .copy {
      padding: 6px 10px;
      color: #dce5df;
      background: rgba(255, 255, 255, .07);
      border: 1px solid rgba(255, 255, 255, .11);
      border-radius: 8px;
      font-size: 12px;
    }
    .copy:hover { background: rgba(255, 255, 255, .14); }
    pre { overflow-x: auto; margin: 0; padding: 19px; font-size: 13px; line-height: 1.68; tab-size: 2; }

    .text-panel {
      overflow: hidden;
      margin: 16px 0 24px;
      color: var(--code-ink);
      background: var(--code);
      border: 1px solid rgba(255, 255, 255, .08);
      border-radius: 15px;
    }
    .text-panel textarea {
      display: block;
      width: 100%;
      min-height: 560px;
      margin: 0;
      padding: 19px;
      resize: vertical;
      color: var(--code-ink);
      background: var(--code);
      border: 0;
      outline: 0;
      font: 13px/1.72 "Cascadia Code", "SFMono-Regular", Consolas, monospace;
      tab-size: 2;
    }

    .dos-donts { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin: 18px 0 24px; }
    .list-box { padding: 18px; border-radius: 14px; }
    .list-box.good { background: color-mix(in srgb, #3b8d68 11%, var(--paper-2)); border: 1px solid color-mix(in srgb, #3b8d68 40%, var(--line)); }
    .list-box.bad { background: color-mix(in srgb, #cf5b48 9%, var(--paper-2)); border: 1px solid color-mix(in srgb, #cf5b48 38%, var(--line)); }
    .list-box h4 { margin: 0 0 9px; }
    .list-box ul, .checklist { margin: 0; padding-left: 20px; }
    .list-box li, .checklist li { margin: 5px 0; }

    .shot-grid {
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 14px;
      margin: 18px 0 26px;
    }
    .guide-shot {
      overflow: hidden;
      margin: 0;
      padding: 10px;
      background: var(--paper-3);
      border: 1px solid var(--line);
      border-radius: 15px;
    }
    .guide-shot.wide { grid-column: 1 / -1; }
    .guide-shot img {
      display: block;
      width: 100%;
      height: auto;
      max-height: 520px;
      object-fit: contain;
      background: #fff;
      border-radius: 9px;
    }
    .guide-shot figcaption {
      padding: 9px 4px 2px;
      color: var(--muted);
      font-size: 13px;
      line-height: 1.55;
    }

    .checklist {
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 10px 24px;
      padding: 0;
      list-style: none;
    }
    .checklist li { position: relative; padding-left: 30px; }
    .checklist li::before {
      content: "✓";
      position: absolute;
      left: 0;
      top: 1px;
      display: grid;
      width: 21px;
      height: 21px;
      place-items: center;
      color: #fff;
      background: #3b8d68;
      border-radius: 50%;
      font-size: 12px;
      font-weight: 900;
    }

    [hidden] { display: none !important; }
    .detail-card-tabs {
      display: grid;
      grid-template-columns: repeat(5, minmax(0, 1fr));
      gap: 10px;
      margin-bottom: 18px;
    }
    .detail-card-tabs button {
      display: grid;
      grid-template-columns: 38px 1fr;
      gap: 10px;
      min-height: 58px;
      align-items: center;
      padding: 10px 14px;
      color: var(--muted);
      background: var(--paper);
      border: 1px solid var(--line);
      border-radius: 13px;
      text-align: left;
      transition: transform .2s, color .2s, background .2s, border-color .2s;
    }
    .detail-card-tabs button:hover { transform: translateY(-2px); border-color: var(--accent); }
    .detail-card-tabs button[aria-selected="true"] { color: #fff; background: var(--accent); border-color: var(--accent); }
    .detail-card-tabs b { display: grid; height: 34px; place-items: center; border: 1px solid currentColor; border-radius: 9px; font-size: 11px; }
    .detail-card-tabs span { font-weight: 800; }
    .detail-subsection {
      scroll-margin-top: 28px;
      margin: 0;
      padding: clamp(20px, 3vw, 30px);
      background: var(--paper);
      border: 1px solid var(--line);
      border-radius: 16px;
      animation: detail-card-in .24s ease both;
    }
    .detail-subhead { max-width: 760px; margin-bottom: 26px; }
    .detail-subhead h3 { margin: 0 0 8px; font-size: clamp(24px, 3.5vw, 32px); }
    .detail-subhead p:last-child { margin: 0; color: var(--muted); }
    .structure-grid {
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 13px;
      margin: 18px 0 28px;
    }
    .structure-card {
      min-width: 0;
      padding: 18px;
      background: var(--paper);
      border: 1px solid var(--line);
      border-radius: 15px;
    }
    .structure-card:last-child { grid-column: 1 / -1; }
    .structure-grid.even-grid .structure-card:last-child { grid-column: auto; }
    .structure-card > header { display: flex; align-items: center; gap: 12px; margin-bottom: 14px; }
    .structure-card > header > span {
      display: grid;
      flex: 0 0 38px;
      height: 38px;
      place-items: center;
      color: #fff;
      background: var(--accent);
      border-radius: 11px;
      font: 800 12px/1 system-ui, sans-serif;
    }
    .structure-card h4 { margin: 0; font-size: 18px; }
    .structure-card header p { margin: 2px 0 0; color: var(--muted); font-size: 13px; }
    .structure-card .nav-format div { grid-template-columns: 78px minmax(0, 1fr); }
    .type-case {
      margin-top: 15px;
      padding: 14px;
      background: var(--paper-2);
      border: 1px solid var(--line);
      border-radius: 12px;
    }
    .type-case-title { display: block; margin-bottom: 10px; color: var(--accent); font-size: 11px; font-weight: 900; letter-spacing: .12em; text-transform: uppercase; }
    .case-button {
      padding: 8px 12px;
      color: #fff;
      background: var(--accent);
      border: 0;
      border-radius: 9px;
      font-weight: 800;
    }
    .case-button:disabled { cursor: default; opacity: .72; }
    .case-whitespace { display: grid; gap: 22px; justify-items: center; padding: 22px; text-align: center; }
    .case-whitespace p, .case-empty p { margin: 0; color: var(--muted); font-size: 13px; }
    .case-grid-preview { display: grid; grid-template-columns: repeat(3, 1fr); gap: 7px; }
    .case-grid-preview span { min-height: 34px; background: color-mix(in srgb, var(--accent) 14%, var(--paper)); border: 1px solid color-mix(in srgb, var(--accent) 34%, var(--line)); border-radius: 8px; }
    .case-micro-preview { padding: 16px; background: var(--paper); border: 1px solid var(--line); border-radius: 12px; transition: transform .2s, color .2s, border-color .2s, box-shadow .2s; }
    .case-micro-preview:hover, .case-micro-preview:focus { color: var(--accent); border-color: var(--accent); box-shadow: 0 12px 24px rgba(27, 35, 31, .12); transform: translateY(-4px); }
    .case-micro-preview:focus { outline: 3px solid var(--accent-2); outline-offset: 2px; }
    .case-micro-preview strong { display: block; margin-bottom: 4px; }
    .case-micro-preview small { color: var(--muted); }
    .case-masonry-preview { columns: 3; column-gap: 7px; }
    .case-masonry-preview span { display: block; break-inside: avoid; margin-bottom: 7px; background: color-mix(in srgb, var(--accent) 17%, var(--paper)); border: 1px solid var(--line); border-radius: 8px; }
    .case-masonry-preview span:nth-child(1), .case-masonry-preview span:nth-child(5) { height: 54px; }
    .case-masonry-preview span:nth-child(2), .case-masonry-preview span:nth-child(6) { height: 34px; }
    .case-masonry-preview span:nth-child(3), .case-masonry-preview span:nth-child(4) { height: 44px; }
    .case-liquid-stage { padding: 24px; background: linear-gradient(135deg, var(--forest), var(--accent)); border-radius: 12px; }
    .case-liquid-panel { padding: 16px; color: #fff; background: rgba(255, 255, 255, .16); border: 1px solid rgba(255, 255, 255, .38); border-radius: 12px; box-shadow: inset 0 1px rgba(255, 255, 255, .2); backdrop-filter: blur(12px) saturate(140%); }
    .case-liquid-panel strong { display: block; margin-bottom: 4px; }
    .case-liquid-panel small { color: rgba(255, 255, 255, .76); }
    .case-skeleton { display: grid; grid-template-columns: 42px 1fr; gap: 10px; align-items: center; }
    .case-skeleton i { width: 42px; height: 42px; background: var(--line); border-radius: 50%; }
    .case-skeleton div { display: grid; gap: 7px; }
    .case-skeleton span { height: 9px; background: var(--line); border-radius: 99px; }
    .case-skeleton span:last-child { width: 66%; }
    .case-empty { display: grid; gap: 8px; justify-items: center; padding: 12px; text-align: center; }
    .case-empty > span { display: grid; width: 42px; height: 42px; place-items: center; color: var(--accent); background: color-mix(in srgb, var(--accent) 12%, var(--paper)); border-radius: 50%; font-size: 22px; }
    .case-form, .case-options { display: grid; gap: 9px; }
    .case-field-label, .case-options legend { color: var(--ink); font-size: 12px; font-weight: 800; }
    .case-control {
      width: 100%;
      min-height: 40px;
      padding: 9px 11px;
      color: var(--ink);
      background: var(--paper);
      border: 1px solid var(--line);
      border-radius: 9px;
      font: inherit;
    }
    textarea.case-control { min-height: 88px; resize: vertical; }
    .case-control:focus-visible, .case-button:focus-visible { outline: 3px solid var(--accent-2); outline-offset: 2px; border-color: var(--accent); }
    .case-options { margin: 0; padding: 0; border: 0; }
    .case-option-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 7px; }
    .case-option { display: flex; gap: 8px; align-items: center; padding: 9px 10px; background: var(--paper); border: 1px solid var(--line); border-radius: 9px; font-size: 13px; }
    .case-option input { accent-color: var(--accent); }
    @keyframes detail-card-in { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }

    .nav-choice {
      display: grid;
      grid-template-columns: 1.05fr .95fr;
      gap: 16px;
      margin: 18px 0 26px;
    }
    .nav-pattern-tabs {
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      gap: 9px;
      align-content: start;
    }
    .nav-pattern-tab {
      min-height: 86px;
      padding: 13px;
      color: var(--ink);
      background: var(--paper);
      border: 1px solid var(--line);
      border-radius: 13px;
      text-align: left;
      transition: transform .2s, color .2s, background .2s, border-color .2s;
    }
    .nav-pattern-tab:hover { transform: translateY(-2px); border-color: var(--accent); }
    .nav-pattern-tab[aria-selected="true"] { color: #fff; background: var(--accent); border-color: var(--accent); }
    .nav-pattern-tab b { display: block; margin-bottom: 5px; font: 800 11px/1 system-ui, sans-serif; letter-spacing: .1em; opacity: .72; }
    .nav-pattern-tab span { display: block; font-weight: 800; }
    .nav-pattern-tab small { display: block; margin-top: 3px; opacity: .72; }
    .nav-pattern-panel {
      overflow: hidden;
      min-width: 0;
      background: var(--paper);
      border: 1px solid var(--line);
      border-radius: 16px;
    }
    .nav-pattern-meta { padding: 20px; }
    .nav-pattern-meta h4 { margin: 0 0 4px; font-size: 23px; }
    .nav-pattern-en { display: block; margin-bottom: 16px; color: var(--muted); font-size: 12px; letter-spacing: .08em; text-transform: uppercase; }
    .nav-format { display: grid; gap: 8px; margin: 0; }
    .nav-format div { display: grid; grid-template-columns: 78px 1fr; gap: 10px; padding-top: 8px; border-top: 1px solid var(--line); }
    .nav-format dt { color: var(--muted); font-size: 12px; font-weight: 800; }
    .nav-format dd { margin: 0; font-size: 14px; }
    .nav-format code { color: var(--accent); overflow-wrap: anywhere; }
    .nav-case-note { margin: 16px 0 0; color: var(--muted); font-size: 13px; }
    .nav-preview-bar { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 10px 14px; color: #cbd5ce; background: var(--forest); font-size: 12px; }
    .nav-preview-bar a { padding: 5px 9px; color: #fff; border: 1px solid rgba(255,255,255,.22); border-radius: 8px; text-decoration: none; }
    .nav-pattern-frame { display: block; width: 100%; height: 420px; background: #fff; border: 0; }
    .nav-decision { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; margin: 16px 0 24px; }
    .nav-decision div { padding: 15px; background: var(--paper); border: 1px solid var(--line); border-radius: 13px; }
    .nav-decision strong { display: block; margin-bottom: 5px; color: var(--accent); }

    footer {
      padding: 36px 22px 52px;
      color: #95a49c;
      background: var(--forest);
      text-align: center;
      font-size: 13px;
    }
    footer strong { color: #eef3ef; }

    @media (max-width: 900px) {
      html { scroll-padding-top: 86px; }
      .layout { display: block; margin-top: 24px; }
      .sidebar { position: sticky; top: 6px; z-index: 30; margin-bottom: 22px; }
      .side-panel { padding: 11px; max-height: none; overflow: visible; }
      .side-title, .side-tip { display: none; }
      .side-nav { display: flex; overflow-x: auto; padding-bottom: 2px; scrollbar-width: thin; }
      .side-nav a { flex: 0 0 auto; grid-template-columns: 25px 1fr; padding: 8px 10px; }
      .side-group { display: flex; flex: 0 0 auto; }
      .side-group-toggle { grid-template-columns: 25px 1fr 16px; width: auto; padding: 8px 10px; white-space: nowrap; }
      .side-subnav { display: flex; flex: 0 0 auto; }
      .side-nav a.sub-link { margin-left: 0; }
      .nav-choice { grid-template-columns: 1fr; }
    }
    @media (min-width: 641px) and (max-width: 1200px) {
      .detail-card-tabs { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    }
    @media (max-width: 640px) {
      .masthead { min-height: 360px; }
      .hero { padding-top: 76px; }
      .utility { right: 16px; top: 16px; }
      .intro-strip { grid-template-columns: 1fr; }
      .chapter { padding: 22px 18px; border-radius: 16px; }
      .chapter-head { grid-template-columns: 48px 1fr; gap: 13px; }
      .chapter-no { width: 48px; height: 48px; border-radius: 14px 14px 14px 4px; font-size: 20px; }
      .cards, .dos-donts, .checklist, .shot-grid, .nav-decision, .structure-grid { grid-template-columns: 1fr; }
      .structure-card:last-child { grid-column: auto; }
      .nav-pattern-tabs { grid-template-columns: repeat(2, minmax(0, 1fr)); }
      .nav-pattern-frame { height: 360px; }
      .detail-card-tabs { grid-template-columns: 1fr; }
      .guide-shot.wide { grid-column: auto; }
      .flow { grid-template-columns: repeat(2, 1fr); }
      .flow div:last-child { grid-column: 1 / -1; }
    }
    @media (prefers-reduced-motion: reduce) {
      *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; }
    }
    @media print {
      :root { --paper: #fff; --paper-2: #fff; --ink: #000; --muted: #444; --line: #bbb; }
      .progress, .utility, .sidebar, .copy, .nav-pattern-frame { display: none !important; }
      .masthead { min-height: auto; color: #000; background: #fff; border-bottom: 3px solid #000; }
      .masthead::before, .masthead::after { display: none; }
      .hero { padding: 30px 0; }
      .hero-lead, .eyebrow, .hero-meta span { color: #222; }
      .layout { display: block; width: 100%; margin: 20px 0; }
      .intro-strip, .chapter { box-shadow: none; break-inside: avoid; }
      .chapter { padding: 24px; }
      .chapter[hidden], .detail-subsection[hidden] { display: block !important; }
      .code-card { color: #111; background: #f4f4f4; border-color: #aaa; }
      .code-head { color: #333; }
      footer { color: #333; background: #fff; }
      footer strong { color: #000; }
    }