/* roulang page: index */
:root {
      color-scheme: light;
      --ink: #202923;
      --muted: #65716a;
      --soft: #eef2ed;
      --paper: #f7f8f5;
      --white: #fff;
      --line: #dfe5de;
      --green: #235c48;
      --green-dark: #194535;
      --coral: #d76755;
      --coral-soft: #faeee9;
      --yellow: #f1d887;
      --radius: 7px;
      --shadow: 0 10px 28px rgba(32, 41, 35, .07);
      --max: 1180px;
      --space: 76px;
    }
    *, *::before, *::after { box-sizing: border-box; }
    html { scroll-behavior: smooth; scroll-padding-top: 90px; }
    body {
      margin: 0;
      background: var(--paper);
      color: var(--ink);
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
      font-size: 16px;
      line-height: 1.72;
      -webkit-font-smoothing: antialiased;
    }
    a { color: inherit; text-decoration: none; }
    a:hover { color: var(--green); }
    img { display: block; max-width: 100%; }
    button, input, select, textarea { font: inherit; }
    button, a, input, select, textarea { -webkit-tap-highlight-color: transparent; }
    button:focus-visible, a:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible {
      outline: 3px solid rgba(215, 103, 85, .48);
      outline-offset: 3px;
    }
    .container { width: min(var(--max), calc(100% - 48px)); margin-inline: auto; }
    .topbar {
      position: sticky;
      z-index: 20;
      top: 0;
      background: rgba(247, 248, 245, .96);
      border-bottom: 1px solid var(--line);
      backdrop-filter: blur(12px);
    }
    .nav-wrap { min-height: 76px; display: flex; align-items: center; justify-content: space-between; gap: 28px; }
    .brand { display: inline-flex; align-items: center; gap: 12px; min-width: 0; font-weight: 750; font-size: 17px; }
    .brand-mark {
      width: 38px; height: 38px; flex: 0 0 38px;
      display: grid; place-items: center;
      background: var(--green); color: #fff; border-radius: 5px;
      font-size: 15px; font-weight: 800;
    }
    .brand-name { line-height: 1.25; }
    .nav-links { display: flex; align-items: center; justify-content: flex-end; gap: 26px; }
    .nav-links a { color: #46534b; font-size: 14px; font-weight: 600; padding: 10px 0; transition: color .18s ease; }
    .nav-links a:hover, .nav-links a[aria-current="page"] { color: var(--coral); }
    .menu-toggle {
      display: none; width: 42px; height: 42px; padding: 0; cursor: pointer;
      border: 1px solid var(--line); border-radius: 5px; background: var(--white); color: var(--ink);
    }
    .menu-toggle span, .menu-toggle::before, .menu-toggle::after {
      display: block; content: ""; width: 18px; height: 2px; margin: 4px auto;
      background: currentColor; transition: transform .18s ease;
    }
    .hero { position: relative; overflow: hidden; padding: 72px 0 58px; background: #e9efe8; }
    .hero::after {
      content: ""; position: absolute; right: max(4vw, calc((100vw - var(--max)) / 2));
      top: 27px; width: min(34vw, 390px); height: 260px;
      border: 1px solid rgba(35,92,72,.16); border-radius: 48% 52% 44% 56%;
      transform: rotate(-13deg); pointer-events: none;
    }
    .hero-inner { position: relative; z-index: 1; max-width: 850px; }
    .hero-kicker, .eyebrow { color: var(--green); font-weight: 750; font-size: 12px; letter-spacing: .08em; text-transform: uppercase; }
    h1 { max-width: 790px; margin: 14px 0 12px; font-size: clamp(34px, 5vw, 57px); line-height: 1.2; letter-spacing: 0; }
    h1 em { color: var(--coral); font-style: normal; }
    .hero-subtitle { margin: 0 0 14px; color: #34463b; font-size: 21px; font-weight: 650; }
    .hero-copy { max-width: 710px; margin: 0; color: #536158; font-size: 16px; line-height: 1.9; }
    .hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 25px; }
    .button {
      min-height: 46px; display: inline-flex; align-items: center; justify-content: center; gap: 8px;
      padding: 10px 19px; border: 1px solid transparent; border-radius: 5px;
      background: var(--green); color: #fff; font-weight: 700; font-size: 14px;
      cursor: pointer; transition: background .18s ease, transform .18s ease, box-shadow .18s ease;
    }
    .button:hover { background: var(--green-dark); color: #fff; transform: translateY(-1px); box-shadow: var(--shadow); }
    .button:active { transform: translateY(0); }
    .button-secondary { background: transparent; color: var(--green); border-color: #9caf9f; }
    .button-secondary:hover { background: #fff; color: var(--green-dark); }
    .hero-note { margin-top: 22px; color: #647168; font-size: 12px; }
    main { display: block; }
    .section { padding: var(--space) 0; border-bottom: 1px solid var(--line); }
    .section.alt { background: #eff3ee; }
    .section.dark { color: #f4f7f3; background: #243b31; border: 0; }
    .section-head { display: flex; align-items: end; justify-content: space-between; gap: 24px; margin-bottom: 28px; }
    .section-head > div { max-width: 760px; }
    .section-index { color: var(--coral); font-size: 12px; font-weight: 800; letter-spacing: .1em; }
    h2 { margin: 5px 0 8px; font-size: clamp(25px, 3vw, 34px); line-height: 1.35; letter-spacing: 0; }
    .section-intro { max-width: 780px; margin: 0; color: var(--muted); font-size: 15px; }
    .dark .section-intro { color: #c7d3cb; }
    .text-link { color: var(--green); font-size: 14px; font-weight: 700; white-space: nowrap; }
    .dark .text-link { color: #f1d887; }
    .stats { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
    .stat { padding: 20px 22px 20px 0; border-right: 1px solid var(--line); }
    .stat:not(:first-child) { padding-left: 22px; }
    .stat:last-child { border-right: 0; }
    .stat strong { display: block; color: var(--green); font-size: 27px; line-height: 1.2; }
    .stat span { display: block; margin-top: 5px; color: var(--muted); font-size: 13px; }
    .stat-note { margin: 13px 0 0; color: var(--muted); font-size: 12px; }
    .matrix { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--line); }
    .matrix-item { min-height: 154px; padding: 21px 20px 18px 0; border-bottom: 1px solid var(--line); }
    .matrix-item:not(:nth-child(4n+1)) { padding-left: 20px; border-left: 1px solid var(--line); }
    .matrix-symbol { color: var(--coral); font-size: 13px; font-weight: 800; }
    .matrix-item h3 { margin: 7px 0 5px; font-size: 17px; }
    .matrix-item p { margin: 0; color: var(--muted); font-size: 13px; line-height: 1.7; }
    .cover-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 24px 18px; }
    .cover-card { min-width: 0; }
    .cover-art {
      position: relative; display: flex; align-items: end; aspect-ratio: 4 / 3;
      overflow: hidden; padding: 15px; border-radius: var(--radius);
      background: #cad9ce; color: var(--ink);
    }
    .cover-art::before, .cover-art::after { position: absolute; content: ""; border-radius: 50%; }
    .cover-art::before { width: 62%; aspect-ratio: 1; top: -20%; right: -6%; background: rgba(255,255,255,.38); }
    .cover-art::after { width: 43%; aspect-ratio: 1; top: 10%; right: 16%; border: 1px solid rgba(32,41,35,.22); }
    .cover-art .art-label { position: relative; z-index: 1; font-size: 11px; font-weight: 800; letter-spacing: .08em; }
    .cover-art .art-number { position: absolute; top: 12px; left: 14px; z-index: 1; color: rgba(32,41,35,.62); font-size: 11px; font-weight: 700; }
    .tone-2 { background: #ead8cb; }
    .tone-3 { background: #d4d8e4; }
    .tone-4 { background: #e7dfb9; }
    .tone-5 { background: #cfddd9; }
    .tone-6 { background: #e7cfcf; }
    .tone-7 { background: #d6dfc8; }
    .tone-8 { background: #d7d1c4; }
    .tone-9 { background: #d3dedf; }
    .tone-10 { background: #e7d6be; }
    .tone-11 { background: #d1d9ca; }
    .tone-12 { background: #e1d0d8; }
    .cover-meta { display: flex; align-items: center; justify-content: space-between; gap: 8px; margin: 11px 0 3px; }
    .cover-meta h3 { overflow: hidden; margin: 0; font-size: 15px; text-overflow: ellipsis; white-space: nowrap; }
    .badge { display: inline-flex; align-items: center; flex: 0 0 auto; padding: 3px 7px; border-radius: 3px; background: #e4eee7; color: var(--green); font-size: 11px; font-weight: 750; }
    .badge.sample { background: var(--coral-soft); color: #9c4639; }
    .cover-card p { margin: 0; color: var(--muted); font-size: 12px; }
    .feature-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 14px; }
    .feature { min-height: 190px; display: flex; flex-direction: column; justify-content: space-between; padding: 19px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--white); }
    .feature:nth-child(2n) { background: #f5eee8; }
    .feature .feature-no { color: var(--coral); font-size: 12px; font-weight: 800; }
    .feature h3 { margin: 13px 0 5px; font-size: 17px; }
    .feature p { margin: 0; color: var(--muted); font-size: 13px; }
    .channel-list { display: grid; grid-template-columns: 1.15fr 1fr 1fr; gap: 0 30px; border-top: 1px solid var(--line); }
    .channel { padding: 18px 0; border-bottom: 1px solid var(--line); }
    .channel h3 { display: flex; align-items: baseline; gap: 10px; margin: 0 0 5px; font-size: 17px; }
    .channel h3 span { color: var(--coral); font-size: 11px; }
    .channel p { margin: 0; color: var(--muted); font-size: 13px; line-height: 1.75; }
    .table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); background: var(--white); }
    .compare-table { width: 100%; border-collapse: collapse; text-align: left; font-size: 13px; }
    .compare-table th, .compare-table td { padding: 14px 16px; border-bottom: 1px solid var(--line); vertical-align: top; }
    .compare-table th { color: var(--green-dark); background: #edf2ed; font-weight: 750; }
    .compare-table tr:last-child td { border-bottom: 0; }
    .compare-table td:first-child { font-weight: 700; }
    .rank-layout { display: grid; grid-template-columns: minmax(0, 1.5fr) minmax(240px, .7fr); gap: 36px; align-items: start; }
    .rank-list { margin: 0; padding: 0; list-style: none; border-top: 1px solid var(--line); }
    .rank-row { display: grid; grid-template-columns: 38px minmax(0, 1fr) 92px 78px; gap: 12px; align-items: center; min-height: 58px; border-bottom: 1px solid var(--line); }
    .rank-no { color: var(--coral); font-size: 15px; font-weight: 800; }
    .rank-title { min-width: 0; font-weight: 650; font-size: 14px; }
    .rank-tag, .rank-value { color: var(--muted); font-size: 12px; }
    .rank-note { padding: 22px; background: var(--coral-soft); border-radius: var(--radius); }
    .rank-note h3 { margin: 0 0 8px; font-size: 17px; }
    .rank-note p { margin: 0; color: #695e58; font-size: 13px; }
    .timeline { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--line); }
    .timeline-item { position: relative; padding: 22px 18px 0 0; }
    .timeline-item::before { position: absolute; top: -5px; left: 0; width: 9px; height: 9px; border: 2px solid var(--coral); border-radius: 50%; background: var(--paper); content: ""; }
    .timeline-item time { color: var(--coral); font-size: 12px; font-weight: 750; }
    .timeline-item h3 { margin: 7px 0 4px; font-size: 16px; }
    .timeline-item p { margin: 0; color: var(--muted); font-size: 13px; }
    .news-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 23px 18px; }
    .news-item { display: grid; grid-template-columns: 116px 1fr; gap: 14px; align-items: center; }
    .news-art { display: grid; place-items: center; aspect-ratio: 4 / 3; border-radius: 5px; background: #d9e4dc; color: var(--green); font-size: 11px; font-weight: 800; }
    .news-item:nth-child(2n) .news-art { background: #ead9cf; color: #8b5143; }
    .news-item time { color: var(--muted); font-size: 11px; }
    .news-item h3 { margin: 3px 0 0; font-size: 14px; line-height: 1.5; }
    .policy-grid { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid rgba(255,255,255,.22); }
    .policy { padding: 18px 18px 0 0; }
    .policy:not(:first-child) { padding-left: 18px; border-left: 1px solid rgba(255,255,255,.22); }
    .policy b { display: block; margin-bottom: 5px; color: #f1d887; font-size: 14px; }
    .policy p { margin: 0; color: #d2ddd5; font-size: 13px; }
    .answers { display: grid; grid-template-columns: 1fr 1fr; gap: 12px 30px; }
    .answer { padding: 15px 0; border-bottom: 1px solid var(--line); }
    .answer h3 { margin: 0 0 5px; font-size: 15px; }
    .answer p { margin: 0; color: var(--muted); font-size: 13px; }
    .faq-list { border-top: 1px solid var(--line); }
    details { border-bottom: 1px solid var(--line); }
    summary { position: relative; padding: 17px 38px 17px 0; cursor: pointer; font-weight: 700; list-style: none; }
    summary::-webkit-details-marker { display: none; }
    summary::after { position: absolute; right: 6px; top: 16px; content: "+"; color: var(--coral); font-size: 20px; font-weight: 400; }
    details[open] summary::after { content: "−"; }
    details p { max-width: 850px; margin: -2px 0 17px; color: var(--muted); font-size: 14px; }
    .feedback-layout { display: grid; grid-template-columns: .85fr 1.15fr; gap: 54px; align-items: start; }
    .feedback-copy h2 { margin-top: 0; }
    .feedback-copy p { color: var(--muted); font-size: 14px; }
    .feedback-form { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
    .field { display: flex; flex-direction: column; gap: 5px; }
    .field.full { grid-column: 1 / -1; }
    .field label { font-size: 13px; font-weight: 700; }
    .field input, .field select, .field textarea {
      width: 100%; min-height: 44px; padding: 10px 12px;
      color: var(--ink); border: 1px solid #cbd5cc; border-radius: 4px; background: #fff;
    }
    .field textarea { min-height: 102px; resize: vertical; }
    .form-actions { grid-column: 1 / -1; display: flex; align-items: center; flex-wrap: wrap; gap: 14px; }
    .form-message { min-height: 24px; margin: 0; color: var(--green); font-size: 13px; }
    .footer { padding: 45px 0 18px; background: #1f3028; color: #edf3ee; }
    .footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 32px; padding-bottom: 32px; }
    .footer-brand { display: inline-flex; align-items: center; gap: 10px; font-size: 16px; font-weight: 750; }
    .footer-brand .brand-mark { background: var(--coral); }
    .footer p { max-width: 310px; margin: 13px 0 0; color: #bdc9c0; font-size: 13px; }
    .footer h3 { margin: 0 0 12px; color: #f1d887; font-size: 13px; }
    .footer-links { display: grid; gap: 7px; }
    .footer-links a { color: #d4ded7; font-size: 13px; }
    .footer-links a:hover { color: #fff; text-decoration: underline; }
    .copyright { padding-top: 16px; border-top: 1px solid rgba(255,255,255,.16); color: #aebbb2; font-size: 12px; }
    .age-layer { position: fixed; z-index: 50; inset: 0; display: grid; place-items: center; padding: 20px; background: rgba(23, 34, 28, .82); }
    .age-layer[hidden] { display: none; }
    .age-dialog { width: min(470px, 100%); padding: 28px; background: var(--paper); border-radius: 7px; box-shadow: 0 20px 70px rgba(0,0,0,.28); }
    .age-dialog h2 { margin: 0 0 8px; font-size: 25px; }
    .age-dialog p { margin: 0; color: var(--muted); font-size: 14px; }
    .age-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }
    .age-warning { margin-top: 14px !important; font-size: 12px !important; }
    @media (max-width: 1024px) {
      :root { --space: 64px; }
      .nav-links { gap: 17px; }
      .cover-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
      .matrix { grid-template-columns: repeat(2, 1fr); }
      .matrix-item:nth-child(odd) { padding-left: 0; border-left: 0; }
      .matrix-item:nth-child(even) { padding-left: 20px; border-left: 1px solid var(--line); }
      .channel-list { grid-template-columns: repeat(2, 1fr); }
      .news-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    }
    @media (max-width: 768px) {
      .container { width: min(100% - 36px, var(--max)); }
      .nav-wrap { min-height: 68px; }
      .menu-toggle { display: block; flex: 0 0 42px; }
      .nav-links {
        position: absolute; display: none; top: 68px; left: 0; right: 0;
        padding: 8px 18px 17px; background: var(--paper); border-bottom: 1px solid var(--line);
        box-shadow: 0 10px 18px rgba(32,41,35,.07);
      }
      .nav-links.is-open { display: grid; grid-template-columns: 1fr 1fr; gap: 2px 18px; }
      .nav-links a { padding: 10px 0; border-bottom: 1px solid var(--line); }
      .hero { padding: 58px 0 48px; }
      .hero::after { right: -95px; top: 20px; opacity: .7; }
      .section-head { align-items: start; flex-direction: column; gap: 10px; }
      .stats { grid-template-columns: repeat(2, 1fr); }
      .stat:nth-child(2) { border-right: 0; }
      .stat:nth-child(3) { padding-left: 0; border-top: 1px solid var(--line); }
      .stat:nth-child(4) { border-top: 1px solid var(--line); }
      .feature-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
      .rank-layout { grid-template-columns: 1fr; }
      .timeline { grid-template-columns: repeat(2, 1fr); row-gap: 20px; }
      .policy-grid { grid-template-columns: repeat(2, 1fr); row-gap: 20px; }
      .policy:nth-child(3) { padding-left: 0; border-left: 0; }
      .feedback-layout { grid-template-columns: 1fr; gap: 20px; }
      .footer-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 520px) {
      :root { --space: 50px; }
      .container { width: calc(100% - 32px); }
      .brand { font-size: 14px; gap: 8px; }
      .brand-mark { width: 34px; height: 34px; flex-basis: 34px; }
      .hero { padding: 48px 0 39px; }
      h1 { font-size: 35px; }
      .hero-subtitle { font-size: 18px; }
      .hero-copy { font-size: 14px; }
      .hero-actions { display: grid; grid-template-columns: 1fr; }
      .button { width: 100%; }
      .cover-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 19px 12px; }
      .cover-art { padding: 10px; }
      .cover-meta { align-items: flex-start; flex-direction: column; gap: 5px; }
      .cover-meta h3 { white-space: normal; }
      .matrix-item { min-height: 145px; padding-right: 10px; }
      .matrix-item:nth-child(even) { padding-left: 12px; }
      .feature-grid { grid-template-columns: 1fr; }
      .channel-list { grid-template-columns: 1fr; }
      .channel { padding: 14px 0; }
      .compare-table { min-width: 610px; }
      .rank-row { grid-template-columns: 28px minmax(0, 1fr) 58px; gap: 8px; padding: 8px 0; }
      .rank-value { grid-column: 2 / -1; margin-top: -9px; }
      .rank-tag { text-align: right; }
      .timeline { grid-template-columns: 1fr 1fr; }
      .news-grid { grid-template-columns: 1fr; gap: 16px; }
      .news-item { grid-template-columns: 94px 1fr; }
      .policy-grid { grid-template-columns: 1fr 1fr; }
      .policy { padding-right: 9px; }
      .policy:not(:first-child) { padding-left: 10px; }
      .policy:nth-child(odd) { padding-left: 0; border-left: 0; }
      .answers { grid-template-columns: 1fr; gap: 0; }
      .feedback-form { grid-template-columns: 1fr; }
      .field.full, .form-actions { grid-column: auto; }
      .footer-grid { grid-template-columns: 1fr 1fr; gap: 25px 18px; }
      .footer-grid > :first-child { grid-column: 1 / -1; }
      .age-dialog { padding: 22px; }
    }
    @media (prefers-reduced-motion: reduce) {
      *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important; }
    }