/* roulang page: index */
:root {
      --ink: #182332;
      --muted: #687586;
      --blue: #2764c5;
      --blue-dark: #194b99;
      --blue-pale: #eaf2ff;
      --teal: #128477;
      --teal-pale: #e6f5f1;
      --coral: #c15a49;
      --coral-pale: #fff0ec;
      --gold: #a66f16;
      --gold-pale: #fff5dc;
      --paper: #ffffff;
      --canvas: #f4f7fb;
      --line: #e2e8f0;
      --shadow: 0 8px 24px rgba(31, 53, 84, .07);
      --radius: 8px;
      --max: 1160px;
    }
    * { box-sizing: border-box; }
    html { scroll-behavior: smooth; scroll-padding-top: 88px; }
    body {
      margin: 0;
      color: var(--ink);
      background: var(--canvas);
      font: 16px/1.7 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    }
    a { color: inherit; text-decoration: none; }
    img { display: block; max-width: 100%; }
    button, input, select, textarea { font: inherit; }
    button, a, input, select, textarea { -webkit-tap-highlight-color: transparent; }
    a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible,
    textarea:focus-visible, summary:focus-visible {
      outline: 3px solid rgba(39, 100, 197, .4);
      outline-offset: 3px;
    }
    .container { width: min(var(--max), calc(100% - 48px)); margin-inline: auto; }
    .topbar {
      position: sticky; top: 0; z-index: 20;
      background: rgba(255,255,255,.96);
      border-bottom: 1px solid var(--line);
      backdrop-filter: blur(12px);
    }
    .nav-wrap { min-height: 72px; display: flex; align-items: center; gap: 28px; }
    .brand { display: inline-flex; align-items: center; gap: 11px; font-weight: 750; white-space: nowrap; }
    .brand-mark {
      width: 36px; height: 36px; display: grid; place-items: center;
      color: #fff; background: var(--blue); border-radius: 7px; font-size: 14px;
    }
    .brand-name { font-size: 17px; }
    .nav-links { display: flex; align-items: center; gap: 25px; margin-left: auto; }
    .nav-links a { color: #4d5a6b; font-size: 14px; transition: color .18s ease; }
    .nav-links a:hover, .nav-links a[aria-current="page"] { color: var(--blue); }
    .nav-cta, .button {
      min-height: 42px; display: inline-flex; align-items: center; justify-content: center;
      padding: 0 17px; border: 1px solid transparent; border-radius: 6px;
      font-weight: 650; transition: background .18s ease, box-shadow .18s ease, color .18s ease;
      cursor: pointer;
    }
    .nav-cta, .button-primary { color: #fff; background: var(--blue); }
    .nav-cta:hover, .button-primary:hover { background: var(--blue-dark); box-shadow: 0 5px 14px rgba(39,100,197,.2); }
    .button-secondary { color: var(--blue-dark); background: #fff; border-color: #cad8ed; }
    .button-secondary:hover { background: var(--blue-pale); }
    .menu-toggle {
      display: none; width: 42px; height: 42px; border: 1px solid var(--line);
      border-radius: 6px; background: #fff; color: var(--ink); cursor: pointer;
    }
    .hero {
      position: relative; overflow: hidden; padding: 76px 0 58px;
      background: #edf4ff;
      border-bottom: 1px solid #dce7f5;
    }
    .hero:after {
      content: ""; position: absolute; width: 390px; height: 390px; right: -95px; top: -180px;
      border: 1px solid rgba(39,100,197,.14); border-radius: 50%;
      box-shadow: 0 0 0 42px rgba(39,100,197,.035), 0 0 0 84px rgba(39,100,197,.025);
      pointer-events: none;
    }
    .hero-inner { position: relative; z-index: 1; max-width: 820px; }
    .eyebrow { margin: 0 0 12px; color: var(--blue-dark); font-size: 13px; font-weight: 700; }
    h1 { max-width: 740px; margin: 0; font-size: clamp(38px, 4.7vw, 58px); line-height: 1.2; font-weight: 760; }
    .hero h1 span { color: var(--blue); }
    .hero-subtitle { margin: 15px 0 0; color: #34465d; font-size: 19px; font-weight: 600; }
    .hero-copy { max-width: 720px; margin: 13px 0 23px; color: #556477; }
    .hero-actions { display: flex; flex-wrap: wrap; gap: 11px; }
    .hero-note { margin: 18px 0 0; color: #718096; font-size: 13px; }
    main { overflow: hidden; }
    .section { padding: 64px 0; border-bottom: 1px solid var(--line); }
    .section-white { background: var(--paper); }
    .section-tint { background: #f7f9fc; }
    .section-head { max-width: 700px; margin-bottom: 27px; }
    .section-kicker { margin: 0 0 6px; color: var(--blue); font-size: 12px; font-weight: 750; }
    h2 { margin: 0; font-size: 29px; line-height: 1.35; }
    .section-intro { margin: 9px 0 0; color: var(--muted); }
    .stats { display: grid; grid-template-columns: repeat(4, 1fr); border: 1px solid var(--line); background: #fff; }
    .stat { padding: 23px 25px; border-right: 1px solid var(--line); }
    .stat:last-child { border-right: 0; }
    .stat strong { display: block; color: var(--blue-dark); font-size: 28px; line-height: 1.2; }
    .stat span { display: block; margin-top: 5px; color: var(--muted); font-size: 13px; }
    .cover-grid { display: grid; grid-template-columns: repeat(4, minmax(0,1fr)); gap: 20px; }
    .story-card { overflow: hidden; background: #fff; border: 1px solid var(--line); border-radius: var(--radius); transition: box-shadow .2s ease, border-color .2s ease; }
    .story-card:hover { border-color: #c5d5ec; box-shadow: var(--shadow); }
    .cover {
      position: relative; aspect-ratio: 4 / 3; display: flex; align-items: flex-end; padding: 14px;
      overflow: hidden; color: #fff; background: linear-gradient(145deg, var(--cover-a), var(--cover-b));
    }
    .cover:before, .cover:after { content: ""; position: absolute; border: 1px solid rgba(255,255,255,.34); }
    .cover:before { width: 120px; height: 160px; right: 18px; top: 17px; transform: rotate(8deg); }
    .cover:after { width: 90px; height: 120px; right: 38px; top: 34px; transform: rotate(-7deg); }
    .cover-label { position: relative; z-index: 1; max-width: 78%; font-size: 17px; font-weight: 700; text-shadow: 0 1px 6px rgba(0,0,0,.25); }
    .cover-1 { --cover-a: #477c9b; --cover-b: #9ac2c2; }
    .cover-2 { --cover-a: #8d6e72; --cover-b: #d8aaa0; }
    .cover-3 { --cover-a: #576d93; --cover-b: #a7bdd1; }
    .cover-4 { --cover-a: #6c887b; --cover-b: #bfd1b1; }
    .cover-5 { --cover-a: #976a51; --cover-b: #d6b58c; }
    .cover-6 { --cover-a: #6c789c; --cover-b: #adb7d4; }
    .cover-7 { --cover-a: #a05e60; --cover-b: #e0a99d; }
    .cover-8 { --cover-a: #4d8184; --cover-b: #a8cfbf; }
    .cover-9 { --cover-a: #65657f; --cover-b: #b4a9c4; }
    .cover-10 { --cover-a: #9a7652; --cover-b: #ddc092; }
    .cover-11 { --cover-a: #47768a; --cover-b: #a2c4c8; }
    .cover-12 { --cover-a: #805c76; --cover-b: #d4a8bd; }
    .story-body { padding: 13px 14px 15px; }
    .story-title { margin: 0; font-size: 15px; line-height: 1.5; }
    .story-meta { display: flex; align-items: center; justify-content: space-between; gap: 8px; margin-top: 10px; color: var(--muted); font-size: 12px; }
    .badge { display: inline-flex; align-items: center; padding: 3px 7px; border-radius: 4px; font-size: 11px; font-weight: 700; }
    .badge-blue { color: #2459a3; background: var(--blue-pale); }
    .badge-green { color: #176d60; background: var(--teal-pale); }
    .badge-gold { color: #865a10; background: var(--gold-pale); }
    .score { color: var(--gold); font-weight: 750; }
    .featured-layout { display: grid; grid-template-columns: 1.4fr 1fr; gap: 24px; }
    .featured-main { min-height: 265px; display: flex; flex-direction: column; justify-content: flex-end; padding: 24px; background: linear-gradient(145deg, #50799b, #9ebdcb); color: #fff; border-radius: 8px; }
    .featured-main h3 { max-width: 500px; margin: 0 0 8px; font-size: 25px; line-height: 1.4; }
    .featured-main p { max-width: 560px; margin: 0; color: rgba(255,255,255,.84); }
    .featured-list { display: grid; gap: 10px; }
    .feature-item { display: grid; grid-template-columns: 68px 1fr auto; gap: 13px; align-items: center; padding: 12px; background: #fff; border: 1px solid var(--line); border-radius: 7px; }
    .feature-thumb { width: 68px; height: 58px; border-radius: 5px; background: linear-gradient(135deg, var(--thumb-a), var(--thumb-b)); }
    .thumb-1 { --thumb-a: #d2a68e; --thumb-b: #6f8e9e; }
    .thumb-2 { --thumb-a: #9bb6a2; --thumb-b: #647493; }
    .thumb-3 { --thumb-a: #c6a17d; --thumb-b: #9a6a73; }
    .thumb-4 { --thumb-a: #8aa4b2; --thumb-b: #d5c093; }
    .feature-item strong { display: block; font-size: 14px; line-height: 1.45; }
    .feature-item small { display: block; margin-top: 3px; color: var(--muted); font-size: 12px; }
    .feature-item .score { font-size: 13px; white-space: nowrap; }
    .matrix { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
    .matrix-item { padding: 21px; background: #fff; border-top: 3px solid var(--matrix); box-shadow: var(--shadow); }
    .matrix-item h3 { margin: 0 0 8px; font-size: 17px; }
    .matrix-item p { margin: 0; color: var(--muted); font-size: 14px; }
    .matrix-blue { --matrix: var(--blue); }
    .matrix-teal { --matrix: var(--teal); }
    .matrix-coral { --matrix: var(--coral); }
    .matrix-gold { --matrix: #c08a25; }
    .compare { display: grid; grid-template-columns: 1fr 1fr; border: 1px solid var(--line); background: #fff; }
    .compare-column { padding: 23px 26px; }
    .compare-column + .compare-column { border-left: 1px solid var(--line); background: #f8fbff; }
    .compare-column h3 { margin: 0 0 15px; font-size: 19px; }
    .compare-column h3 span { display: inline-block; margin-right: 8px; color: var(--blue); }
    .compare-list { display: grid; gap: 13px; margin: 0; padding: 0; list-style: none; }
    .compare-list li { position: relative; padding-left: 23px; color: #526174; font-size: 14px; }
    .compare-list li:before { content: "✓"; position: absolute; left: 0; color: var(--teal); font-weight: 800; }
    .timeline { position: relative; display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
    .timeline:before { content: ""; position: absolute; top: 12px; left: 8%; right: 8%; height: 1px; background: #cbd9ea; }
    .milestone { position: relative; padding-top: 35px; }
    .milestone:before { content: ""; position: absolute; top: 5px; left: 0; width: 15px; height: 15px; border: 4px solid #d9e7fa; border-radius: 50%; background: var(--blue); }
    .milestone time { color: var(--blue-dark); font-size: 13px; font-weight: 750; }
    .milestone h3 { margin: 7px 0 5px; font-size: 16px; }
    .milestone p { margin: 0; color: var(--muted); font-size: 13px; }
    .ranking-wrap { display: grid; grid-template-columns: 1.3fr .7fr; gap: 26px; align-items: start; }
    .ranking { overflow: hidden; background: #fff; border: 1px solid var(--line); }
    .rank-row { display: grid; grid-template-columns: 44px minmax(0,1fr) 92px 62px 88px; gap: 10px; align-items: center; padding: 13px 16px; border-bottom: 1px solid #edf0f4; }
    .rank-row:last-child { border-bottom: 0; }
    .rank-row:hover { background: #f7faff; }
    .rank-number { color: #9aa7b7; font-size: 18px; font-weight: 750; }
    .rank-row:nth-child(2) .rank-number { color: #c58a1d; }
    .rank-row:nth-child(3) .rank-number { color: #708399; }
    .rank-name { min-width: 0; font-weight: 650; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
    .rank-row small { color: var(--muted); font-size: 12px; }
    .rank-hot { color: var(--coral); font-size: 13px; font-weight: 700; }
    .rank-score { color: var(--gold); font-weight: 750; }
    .ranking-note { padding: 24px; background: var(--blue-dark); color: #fff; }
    .ranking-note h3 { margin: 0 0 11px; font-size: 21px; }
    .ranking-note p { margin: 0; color: rgba(255,255,255,.78); font-size: 14px; }
    .news-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
    .news-item { display: grid; grid-template-columns: 108px 1fr; gap: 15px; padding: 13px; background: #fff; border: 1px solid var(--line); border-radius: 7px; }
    .news-image { min-height: 88px; border-radius: 5px; background: linear-gradient(135deg, var(--news-a), var(--news-b)); }
    .news-a { --news-a: #7b9eb1; --news-b: #d2bb9c; }
    .news-b { --news-a: #a87372; --news-b: #d8b3a0; }
    .news-c { --news-a: #718d82; --news-b: #c3d1bd; }
    .news-d { --news-a: #6d789e; --news-b: #b8c0db; }
    .news-e { --news-a: #a17a57; --news-b: #dbc198; }
    .news-f { --news-a: #758f9b; --news-b: #b4ced0; }
    .news-item h3 { margin: 2px 0 7px; font-size: 15px; line-height: 1.5; }
    .news-item time { color: var(--muted); font-size: 12px; }
    .assurance { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; border: 1px solid var(--line); background: #fff; }
    .assurance-item { padding: 24px 27px; border-right: 1px solid var(--line); }
    .assurance-item:last-child { border-right: 0; }
    .assurance-icon { width: 38px; height: 38px; display: grid; place-items: center; margin-bottom: 12px; color: var(--blue); background: var(--blue-pale); border-radius: 50%; font-weight: 800; }
    .assurance-item h3 { margin: 0 0 6px; font-size: 17px; }
    .assurance-item p { margin: 0; color: var(--muted); font-size: 14px; }
    .quick-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
    .quick-item { padding: 18px; background: #fff; border: 1px solid var(--line); }
    .quick-item strong { display: block; margin-bottom: 6px; color: var(--blue-dark); font-size: 15px; }
    .quick-item p { margin: 0; color: var(--muted); font-size: 13px; }
    .faq-list { max-width: 850px; border-top: 1px solid var(--line); }
    details { padding: 18px 0; border-bottom: 1px solid var(--line); }
    summary { cursor: pointer; list-style: none; font-weight: 700; padding-right: 30px; position: relative; }
    summary::-webkit-details-marker { display: none; }
    summary:after { content: "+"; position: absolute; right: 3px; color: var(--blue); font-size: 21px; font-weight: 400; }
    details[open] summary:after { content: "−"; }
    details p { max-width: 760px; margin: 10px 0 0; color: var(--muted); font-size: 14px; }
    .conversion { padding: 48px 0; background: var(--blue-dark); color: #fff; }
    .conversion-layout { display: grid; grid-template-columns: .9fr 1.1fr; gap: 55px; align-items: center; }
    .conversion h2 { color: #fff; }
    .conversion p { color: rgba(255,255,255,.77); }
    .conversion-form { padding: 25px; background: #fff; color: var(--ink); border-radius: 8px; }
    .form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 15px; }
    .field { display: grid; gap: 6px; }
    .field-full { grid-column: 1 / -1; }
    label { color: #425066; font-size: 13px; font-weight: 650; }
    input, select, textarea { width: 100%; padding: 10px 12px; border: 1px solid #d6deea; border-radius: 5px; color: var(--ink); background: #fff; transition: border-color .18s ease, box-shadow .18s ease; }
    textarea { min-height: 88px; resize: vertical; }
    input::placeholder, textarea::placeholder { color: #9ba7b5; }
    input:focus, select:focus, textarea:focus { border-color: var(--blue); box-shadow: 0 0 0 3px rgba(39,100,197,.12); outline: none; }
    .form-actions { display: flex; align-items: center; gap: 13px; margin-top: 16px; }
    .form-hint { color: #7c8795; font-size: 12px; }
    .form-feedback { min-height: 20px; margin: 11px 0 0; color: var(--teal); font-size: 13px; }
    footer { padding: 48px 0 20px; color: #b9c8db; background: #172436; }
    .footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 36px; padding-bottom: 35px; }
    .footer-brand { color: #fff; }
    .footer-brand p { max-width: 290px; margin: 13px 0 0; color: #9eafc4; font-size: 13px; }
    footer h3 { margin: 0 0 12px; color: #fff; font-size: 14px; }
    .footer-links { display: grid; gap: 8px; }
    .footer-links a { color: #aabbd0; font-size: 13px; }
    .footer-links a:hover { color: #fff; }
    .copyright { padding-top: 17px; border-top: 1px solid rgba(255,255,255,.12); color: #899bb1; font-size: 12px; }
    @media (max-width: 1024px) {
      .cover-grid { grid-template-columns: repeat(3, 1fr); }
      .matrix { grid-template-columns: repeat(2, 1fr); }
      .quick-grid { grid-template-columns: repeat(2, 1fr); }
      .ranking-wrap { grid-template-columns: 1fr; }
    }
    @media (max-width: 768px) {
      .container { width: min(var(--max), calc(100% - 32px)); }
      .nav-wrap { min-height: 64px; }
      .menu-toggle { display: grid; place-items: center; margin-left: auto; font-size: 20px; }
      .nav-links { display: none; position: absolute; top: 64px; left: 0; right: 0; padding: 13px 16px 18px; background: #fff; border-bottom: 1px solid var(--line); box-shadow: 0 10px 18px rgba(31,53,84,.09); }
      .nav-links.is-open { display: grid; gap: 0; }
      .nav-links a { padding: 11px 4px; border-bottom: 1px solid #eef1f5; }
      .nav-links .nav-cta { margin-top: 11px; border-bottom: 0; }
      .hero { padding: 54px 0 44px; }
      h1 { font-size: 41px; }
      .stats { grid-template-columns: repeat(2, 1fr); }
      .stat:nth-child(2) { border-right: 0; }
      .stat:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
      .stat { padding: 18px; }
      .featured-layout, .conversion-layout { grid-template-columns: 1fr; gap: 24px; }
      .timeline { grid-template-columns: repeat(2, 1fr); row-gap: 28px; }
      .timeline:before { display: none; }
      .news-grid { grid-template-columns: repeat(2, 1fr); }
      .assurance { grid-template-columns: 1fr; }
      .assurance-item { border-right: 0; border-bottom: 1px solid var(--line); }
      .assurance-item:last-child { border-bottom: 0; }
      .footer-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 520px) {
      .container { width: min(var(--max), calc(100% - 24px)); }
      .brand-name { font-size: 15px; }
      .hero { padding-top: 43px; }
      h1 { font-size: 35px; }
      .hero-subtitle { font-size: 17px; }
      .hero-actions .button { width: 100%; }
      .section { padding: 45px 0; }
      h2 { font-size: 25px; }
      .cover-grid { grid-template-columns: repeat(2, 1fr); gap: 11px; }
      .cover-label { font-size: 14px; }
      .story-body { padding: 10px; }
      .story-title { font-size: 14px; }
      .matrix, .quick-grid, .news-grid { grid-template-columns: 1fr; }
      .compare { grid-template-columns: 1fr; }
      .compare-column + .compare-column { border-left: 0; border-top: 1px solid var(--line); }
      .timeline { grid-template-columns: 1fr; }
      .rank-row { grid-template-columns: 30px minmax(0,1fr) 58px; padding: 12px 10px; }
      .rank-row small, .rank-row .badge { display: none; }
      .rank-hot { font-size: 12px; }
      .news-item { grid-template-columns: 86px 1fr; }
      .form-grid { grid-template-columns: 1fr; }
      .field-full { grid-column: auto; }
      .form-actions { align-items: stretch; flex-direction: column; }
      .form-actions .button { width: 100%; }
      .footer-grid { grid-template-columns: 1fr 1fr; gap: 25px 18px; }
      .footer-brand { grid-column: 1 / -1; }
    }