/* roulang page: index */
:root {
      --brand: #1E6F8F;
      --brand-ink: #164A5E;
      --brand-soft: #D7EAF1;
      --accent: #C9782A;
      --bg: #F3F6F8;
      --surface: #FFFFFF;
      --text: #1B2830;
      --muted: #5A6A73;
      --line: #E2E8EC;
      --dark: #14323C;
      --radius-card: 14px;
      --radius-btn: 8px;
      --radius-pill: 999px;
      --shadow: 0 10px 28px rgba(20,50,60,.07);
      --shadow-hover: 0 16px 36px rgba(20,50,60,.12);
      --space-section: 96px;
      --space-card: 28px;
      --wrap: 1200px;
    }
    *, *::before, *::after { box-sizing: border-box; }
    html { scroll-behavior: smooth; }
    html, body { margin: 0; padding: 0; }
    body {
      font-family: "PingFang SC","Noto Sans SC","Source Han Sans SC","Microsoft YaHei",sans-serif;
      font-size: 16px;
      font-weight: 400;
      line-height: 1.75;
      color: var(--text);
      background: var(--bg);
      overflow-x: hidden;
    }
    img { max-width: 100%; height: auto; display: block; }
    a { color: inherit; text-decoration: none; }
    button, input, select, textarea { font-family: inherit; }
    button { cursor: pointer; }
    h1, h2, h3, h4 { margin: 0; color: var(--text); letter-spacing: .01em; }
    h1 { font-size: 44px; line-height: 1.22; font-weight: 700; }
    h2 { font-size: 30px; line-height: 1.3; font-weight: 700; }
    h3 { font-size: 19px; line-height: 1.4; font-weight: 650; }
    p { margin: 0; }
    ul { margin: 0; padding: 0; list-style: none; }
    .container {
      width: min(100% - 40px, var(--wrap));
      margin: 0 auto;
    }
    .container-wide { width: min(100% - 40px, 1280px); margin: 0 auto; }
    ::selection { background: var(--brand-soft); color: var(--brand-ink); }
    :focus-visible {
      outline: 2px solid var(--brand);
      outline-offset: 2px;
    }
    .shelf-bg {
      background-color: var(--bg);
      background-image:
        linear-gradient(rgba(30,111,143,.035) 1px, transparent 1px),
        linear-gradient(90deg, rgba(30,111,143,.035) 1px, transparent 1px);
      background-size: 28px 36px;
    }
    .site-header { position: relative; z-index: 50; }
    .util-bar {
      background: var(--brand-soft);
      color: var(--brand-ink);
      font-size: 13px;
      line-height: 1.4;
      border-bottom: 1px solid var(--line);
    }
    .util-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 16px;
      min-height: 38px;
      flex-wrap: wrap;
    }
    .util-left { display: flex; align-items: center; gap: 18px; flex-wrap: wrap; }
    .util-item { display: inline-flex; align-items: center; gap: 6px; }
    .util-dot { width: 6px; height: 6px; border-radius: 50%; background: var(--brand); display: inline-block; }
    .util-link { color: var(--brand-ink); font-weight: 650; }
    .util-link:hover { color: var(--brand); }
    .nav-wrap {
      background: var(--surface);
      border-bottom: 1px solid transparent;
      transition: box-shadow .25s ease, border-color .25s ease;
    }
    .nav-wrap.is-stuck {
      position: sticky;
      top: 0;
      z-index: 60;
      border-bottom-color: var(--line);
      box-shadow: 0 8px 20px rgba(20,50,60,.06);
    }
    .nav-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 18px;
      min-height: 72px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      flex-shrink: 0;
      color: var(--brand-ink);
      font-weight: 700;
      font-size: 17px;
    }
    .logo-mark {
      width: 36px; height: 36px; border-radius: 10px;
      background: var(--brand);
      color: #fff;
      display: grid; place-items: center;
      box-shadow: var(--shadow);
    }
    .logo-mark svg { width: 20px; height: 20px; }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 4px;
      flex-wrap: wrap;
    }
    .nav-links a {
      padding: 8px 10px;
      font-size: 14px;
      color: var(--muted);
      border-radius: 8px;
      transition: color .2s, background .2s;
    }
    .nav-links a:hover, .nav-links a.is-active {
      color: var(--brand-ink);
      background: var(--brand-soft);
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      min-height: 44px;
      padding: 0 18px;
      border-radius: var(--radius-btn);
      font-size: 14px;
      font-weight: 650;
      border: 1px solid transparent;
      transition: background .2s, transform .2s, box-shadow .2s, border-color .2s, color .2s;
    }
    .btn-primary { background: var(--brand); color: #fff; }
    .btn-primary:hover { background: #185c77; box-shadow: var(--shadow); transform: translateY(-1px); }
    .btn-primary:active { transform: translateY(0); background: var(--brand-ink); }
    .btn-ghost {
      background: #fff;
      color: var(--brand-ink);
      border-color: var(--line);
    }
    .btn-ghost:hover { border-color: var(--brand); color: var(--brand); box-shadow: var(--shadow); transform: translateY(-1px); }
    .btn-light { background: #fff; color: var(--brand-ink); }
    .btn-light:hover { background: var(--brand-soft); }
    .menu-toggle {
      display: none;
      width: 44px; height: 44px;
      border: 1px solid var(--line);
      background: #fff;
      border-radius: 8px;
      align-items: center;
      justify-content: center;
    }
    .menu-toggle span, .menu-toggle span::before, .menu-toggle span::after {
      display: block; width: 18px; height: 2px; background: var(--brand-ink); border-radius: 2px; position: relative;
    }
    .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; }
    .drawer {
      position: fixed; inset: 0 0 0 auto; width: min(86vw, 360px);
      background: #fff; z-index: 80;
      transform: translateX(100%);
      transition: transform .35s ease;
      box-shadow: -16px 0 40px rgba(20,50,60,.12);
      padding: 24px;
      display: flex; flex-direction: column; gap: 12px;
    }
    .drawer.open { transform: translateX(0); }
    .drawer-mask {
      position: fixed; inset: 0; background: rgba(20,50,60,.35); z-index: 70;
      opacity: 0; pointer-events: none; transition: opacity .3s;
    }
    .drawer-mask.show { opacity: 1; pointer-events: auto; }
    .drawer a {
      padding: 12px 8px; border-bottom: 1px solid var(--line); color: var(--text); font-weight: 650;
    }
    .section { padding: var(--space-section) 0; position: relative; }
    .section-white { background: #fff; }
    .section-soft { background: var(--brand-soft); }
    .section-alt { background: var(--bg); }
    .kicker {
      display: inline-flex; align-items: center; gap: 8px;
      color: var(--brand); font-size: 13px; font-weight: 650; margin-bottom: 10px;
    }
    .kicker::before { content: ""; width: 18px; height: 2px; background: var(--brand); border-radius: 2px; }
    .lead { color: var(--muted); max-width: 720px; margin-top: 12px; }
    .badge {
      display: inline-flex; align-items: center; gap: 4px;
      background: var(--brand-soft); color: var(--brand-ink);
      border-radius: var(--radius-pill); padding: 3px 10px; font-size: 12px; font-weight: 650;
    }
    .badge-warn { background: rgba(201,120,42,.12); color: var(--accent); }
    .card {
      background: var(--surface);
      border: 1px solid var(--line);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow);
      transition: transform .22s ease, box-shadow .22s ease;
    }
    .card:hover { transform: translateY(-2px); box-shadow: var(--shadow-hover); }
    .hero {
      position: relative;
      min-height: 620px;
      overflow: hidden;
      background: #dfe8ec;
    }
    .hero-track {
      position: absolute; inset: 0;
      display: flex; width: 300%;
      transition: transform .45s ease;
    }
    .hero-slide {
      width: 33.3333%;
      position: relative;
      background: #c5d4da center/cover no-repeat;
    }
    .hero-slide::after {
      content: ""; position: absolute; inset: 0;
      background: linear-gradient(90deg, rgba(243,246,248,.88) 0%, rgba(243,246,248,.62) 46%, rgba(20,50,60,.28) 100%);
    }
    .hero-copy {
      position: relative; z-index: 2;
      padding: 92px 0 78px;
      max-width: 720px;
    }
    .hero h1 { max-width: 16ch; }
    .hero-desc { margin-top: 16px; color: var(--text); max-width: 640px; }
    .hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 24px; }
    .hero-panel {
      position: relative; z-index: 2;
      margin-top: 28px;
      display: grid;
      grid-template-columns: 1.2fr .8fr;
      gap: 16px;
      max-width: 720px;
    }
    .demo-card, .seat-card {
      background: rgba(255,255,255,.94);
      border: 1px solid var(--line);
      border-radius: 14px;
      padding: 18px 20px;
      box-shadow: var(--shadow);
    }
    .count-row { display: flex; gap: 8px; margin-top: 10px; }
    .count-box {
      min-width: 58px; text-align: center; background: var(--bg);
      border: 1px solid var(--line); border-radius: 10px; padding: 8px 6px;
    }
    .count-box b { display: block; font-size: 22px; font-variant-numeric: tabular-nums; color: var(--brand-ink); }
    .count-box span { font-size: 12px; color: var(--muted); }
    .progress { height: 8px; background: #e8eef1; border-radius: 999px; overflow: hidden; margin-top: 10px; }
    .progress > i { display: block; height: 100%; width: 40%; background: var(--brand); border-radius: 999px; }
    .hero-nav {
      position: absolute; z-index: 3; bottom: 22px; right: max(20px, calc((100% - 1200px) / 2));
      display: flex; align-items: center; gap: 10px;
    }
    .hero-arrow {
      width: 44px; height: 44px; border-radius: 8px;
      border: 1px solid var(--line); background: #fff; color: var(--brand-ink);
      display: grid; place-items: center;
    }
    .hero-arrow:hover { background: var(--brand); color: #fff; border-color: var(--brand); }
    .hero-dots { display: flex; gap: 6px; }
    .hero-dots button {
      width: 10px; height: 8px; border: 0; border-radius: 999px; background: #c9d6dc;
    }
    .hero-dots button.is-on { width: 28px; background: var(--brand); }
    .split {
      display: grid; grid-template-columns: 1.05fr .95fr; gap: 48px; align-items: center;
    }
    .cover-frame {
      border-radius: 14px; overflow: hidden; box-shadow: var(--shadow);
      border: 1px solid var(--line); background: #fff;
    }
    .cover-frame img { width: 100%; height: 420px; object-fit: cover; }
    .spec-list { margin-top: 18px; display: grid; gap: 10px; }
    .spec-list li {
      display: grid; grid-template-columns: 16px 1fr; gap: 10px; color: var(--text);
    }
    .spec-list i {
      width: 16px; height: 16px; margin-top: 6px; border-radius: 50%;
      background: var(--brand-soft); box-shadow: inset 0 0 0 4px var(--brand);
    }
    .chip-row { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 18px; }
    .chip {
      border: 1px solid var(--line); background: #fff; color: var(--brand-ink);
      border-radius: 999px; padding: 6px 12px; font-size: 13px;
    }
    .chip:hover { border-color: var(--brand); background: var(--brand-soft); }
    .bento {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      grid-auto-rows: minmax(168px, auto);
      gap: 16px;
      margin-top: 32px;
    }
    .tile {
      background: #fff; border: 1px solid var(--line); border-radius: 14px;
      box-shadow: var(--shadow); padding: 24px; display: flex; flex-direction: column; gap: 10px;
    }
    .tile:hover { transform: translateY(-2px); box-shadow: var(--shadow-hover); }
    .tile-lg { grid-column: span 2; grid-row: span 2; background:
      linear-gradient(180deg, #fff 0%, #f7fbfd 100%); }
    .icon-line {
      width: 40px; height: 40px; border-radius: 10px;
      border: 1px solid var(--line); display: grid; place-items: center; color: var(--brand);
    }
    .tile ul { display: grid; gap: 6px; color: var(--muted); font-size: 14px; }
    .tile ul li { padding-left: 12px; position: relative; }
    .tile ul li::before { content: ""; width: 5px; height: 5px; border-radius: 50%; background: var(--brand); position: absolute; left: 0; top: 9px; }
    .tile-cta { margin-top: auto; color: var(--brand); font-size: 14px; font-weight: 650; }
    .adv-grid {
      display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-top: 32px;
    }
    .adv-card { padding: 28px; }
    .adv-card h3 { margin: 8px 0 8px; }
    .adv-card p { color: var(--muted); font-size: 15px; }
    .metric { font-size: 28px; color: var(--brand); font-weight: 700; font-variant-numeric: tabular-nums; }
    .prod-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-top: 32px; }
    .prod-card { overflow: hidden; display: flex; flex-direction: column; }
    .prod-card img { width: 100%; height: 190px; object-fit: cover; }
    .prod-body { padding: 22px 22px 8px; }
    .prod-bar {
      margin-top: auto; display: grid; grid-template-columns: repeat(3, 1fr);
      border-top: 1px solid var(--line); background: #f8fbfc;
    }
    .prod-bar div { padding: 12px 8px; text-align: center; font-size: 12px; color: var(--muted); border-right: 1px solid var(--line); }
    .prod-bar div:last-child { border-right: 0; }
    .prod-bar b { display: block; color: var(--brand-ink); font-size: 13px; }
    .rank-side {
      margin-top: 28px; background: #fff; border: 1px solid var(--line); border-radius: 14px;
      box-shadow: var(--shadow); padding: 22px 24px;
    }
    .rank-item {
      display: grid; grid-template-columns: 28px 1fr auto; gap: 12px; align-items: center;
      padding: 10px 0; border-bottom: 1px dashed var(--line);
    }
    .rank-item:last-child { border-bottom: 0; }
    .rank-no { font-variant-numeric: tabular-nums; color: var(--brand); font-weight: 700; }
    .stats {
      display: grid; grid-template-columns: repeat(5, 1fr); gap: 12px;
    }
    .stat {
      text-align: center; padding: 18px 8px;
    }
    .stat b {
      display: block; font-size: 36px; line-height: 1.1; color: var(--brand-ink);
      font-variant-numeric: tabular-nums; font-weight: 700;
    }
    .stat span { color: var(--muted); font-size: 13px; }
    .timeline {
      display: grid; grid-template-columns: repeat(5, 1fr); gap: 16px; margin-top: 36px; position: relative;
    }
    .timeline::before {
      content: ""; position: absolute; left: 8%; right: 8%; top: 28px; height: 2px; background: var(--brand-soft);
    }
    .step { position: relative; background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: 24px 20px 20px; box-shadow: var(--shadow); }
    .step-no {
      width: 36px; height: 36px; border-radius: 50%; background: var(--brand); color: #fff;
      display: grid; place-items: center; font-weight: 700; margin-bottom: 12px; position: relative; z-index: 1;
    }
    .step p { color: var(--muted); font-size: 14px; margin-top: 8px; }
    .dark-block {
      background: var(--dark); color: #d7e6ec; padding: 96px 0;
    }
    .dark-grid { display: grid; grid-template-columns: 1.1fr .9fr; gap: 48px; align-items: center; }
    .dark-block h2 { color: #fff; }
    .idea { display: grid; gap: 14px; }
    .idea li {
      background: rgba(255,255,255,.05); border: 1px solid rgba(255,255,255,.08);
      border-radius: 12px; padding: 16px 18px;
    }
    .idea b { color: #fff; display: block; margin-bottom: 4px; }
    .case-wall {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      grid-auto-rows: 170px;
      gap: 14px;
      margin-top: 32px;
    }
    .case {
      position: relative; overflow: hidden; border-radius: 14px; color: #fff;
      border: 1px solid var(--line); cursor: pointer; display: flex; align-items: flex-end;
      background: #1b3a44 center/cover no-repeat;
    }
    .case::after {
      content: ""; position: absolute; inset: 0;
      background: linear-gradient(180deg, rgba(20,50,60,.1), rgba(20,50,60,.78));
    }
    .case > div { position: relative; z-index: 1; padding: 16px; }
    .case.big { grid-column: span 2; grid-row: span 2; }
    .case.mid { grid-column: span 2; }
    .story-grid { display: grid; grid-template-columns: 1.3fr .7fr; gap: 18px; margin-top: 32px; }
    .story-main { overflow: hidden; }
    .story-main img { width: 100%; height: 280px; object-fit: cover; }
    .quote { padding: 24px 28px 28px; }
    .quote p { font-size: 18px; line-height: 1.7; }
    .side-notes { display: grid; gap: 14px; }
    .side-notes article { padding: 22px; }
    .review-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; margin-top: 32px; }
    .review { padding: 24px; position: relative; }
    .review::before { content: "“"; position: absolute; top: 8px; left: 16px; font-size: 42px; color: var(--brand-soft); }
    .stars { color: var(--accent); letter-spacing: 2px; font-size: 13px; margin-bottom: 8px; }
    .tabs { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 24px; }
    .tab {
      min-height: 44px; padding: 0 16px; border-radius: 999px; border: 1px solid var(--line);
      background: #fff; color: var(--muted); font-weight: 650;
    }
    .tab.is-on { background: var(--brand); color: #fff; border-color: var(--brand); }
    .scene-panel { display: none; margin-top: 22px; }
    .scene-panel.is-on { display: grid; grid-template-columns: 1.1fr .9fr; gap: 24px; align-items: center; }
    .scene-panel img { width: 100%; height: 320px; object-fit: cover; border-radius: 14px; }
    .scene-list { display: grid; gap: 12px; margin-top: 12px; }
    .scene-list li { background: #fff; border: 1px solid var(--line); border-radius: 12px; padding: 14px 16px; }
    .news-grid { display: grid; grid-template-columns: 1.15fr .85fr; gap: 18px; margin-top: 28px; }
    .news-feature { overflow: hidden; }
    .news-feature img { width: 100%; height: 260px; object-fit: cover; }
    .news-feature .pad, .news-list a { padding: 22px; display: block; }
    .news-list { display: grid; gap: 12px; }
    .news-list a { background: #fff; border: 1px solid var(--line); border-radius: 14px; box-shadow: var(--shadow); border-left: 4px solid var(--brand); }
    .news-list a:hover { transform: translateY(-2px); box-shadow: var(--shadow-hover); }
    .date { font-size: 13px; color: var(--muted); }
    .logo-wall {
      display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin-top: 28px;
    }
    .logo-slot {
      min-height: 84px; background: #fff; border: 1px dashed var(--line); border-radius: 12px;
      display: grid; place-items: center; color: var(--muted); font-weight: 650; letter-spacing: .08em;
      filter: grayscale(1); opacity: .85;
    }
    .faq { display: grid; gap: 10px; margin-top: 28px; }
    .faq-item { background: #fff; border: 1px solid var(--line); border-radius: 14px; overflow: hidden; box-shadow: var(--shadow); }
    .faq-q {
      width: 100%; background: #fff; border: 0; text-align: left;
      padding: 18px 52px 18px 22px; font-size: 16px; font-weight: 650; position: relative; color: var(--text);
    }
    .faq-q .mark {
      position: absolute; right: 18px; top: 50%; transform: translateY(-50%);
      width: 28px; height: 28px; border-radius: 50%; background: var(--brand-soft); color: var(--brand-ink);
      display: grid; place-items: center; font-size: 18px;
    }
    .faq-a { display: none; padding: 0 22px 18px; color: var(--muted); background: #f8fbfc; }
    .faq-item.open .faq-a { display: block; }
    .guard-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
    .guard { padding: 24px; }
    .contact-grid { display: grid; grid-template-columns: 1.15fr .85fr; gap: 28px; align-items: start; }
    .form { display: grid; gap: 14px; }
    .field { display: grid; gap: 6px; }
    .field span { font-size: 13px; color: var(--brand-ink); font-weight: 650; }
    .field input, .field select, .field textarea {
      min-height: 46px; border: 1px solid var(--line); border-radius: 12px; padding: 10px 12px; background: #fff;
    }
    .field input:focus, .field select:focus, .field textarea:focus {
      border-color: var(--brand); box-shadow: 0 0 0 3px rgba(30,111,143,.12); outline: none;
    }
    .checks { display: flex; flex-wrap: wrap; gap: 10px; }
    .checks label { display: inline-flex; align-items: center; gap: 6px; font-size: 14px; }
    .err { color: #b42318; font-size: 13px; min-height: 18px; }
    .ok-box {
      display: none; background: var(--brand-soft); color: var(--brand-ink);
      border-radius: 12px; padding: 14px 16px; font-weight: 650;
    }
    .aside-box { padding: 28px; }
    .aside-box li { padding: 10px 0; border-bottom: 1px solid var(--line); color: var(--muted); }
    .aside-box li b { display: block; color: var(--text); }
    .site-footer { background: var(--dark); color: #c5d5dc; padding: 56px 0 0; }
    .foot-grid { display: grid; grid-template-columns: 1.3fr .9fr .9fr; gap: 32px; padding-bottom: 36px; }
    .site-footer h3 { color: #fff; margin-bottom: 12px; }
    .site-footer a { color: #c5d5dc; }
    .site-footer a:hover { color: #fff; }
    .icp {
      border-top: 1px solid rgba(255,255,255,.08); padding: 16px 0 22px;
      display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; font-size: 13px; color: #9bb0b8;
    }
    @media (max-width: 1280px) {
      h1 { font-size: 40px; }
    }
    @media (max-width: 1024px) {
      .util-bar { display: none; }
      .nav-links, .nav-cta { display: none; }
      .menu-toggle { display: inline-flex; }
      .split, .dark-grid, .story-grid, .news-grid, .contact-grid, .scene-panel.is-on, .hero-panel {
        grid-template-columns: 1fr;
      }
      .bento { grid-template-columns: repeat(2, 1fr); }
      .tile-lg { grid-column: span 2; grid-row: span 1; }
      .adv-grid, .prod-grid, .review-grid, .guard-grid, .stats { grid-template-columns: repeat(2, 1fr); }
      .timeline { grid-template-columns: 1fr 1fr; }
      .timeline::before { display: none; }
      .case-wall { grid-template-columns: 1fr 1fr; grid-auto-rows: 180px; }
      .hero { min-height: 0; }
      .hero-copy { padding: 56px 0 88px; }
      .foot-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      :root { --space-section: 64px; }
      h1 { font-size: 30px; }
      h2 { font-size: 23px; }
      .bento, .adv-grid, .prod-grid, .review-grid, .guard-grid, .stats, .logo-wall, .timeline, .case-wall, .foot-grid {
        grid-template-columns: 1fr;
      }
      .tile-lg, .case.big, .case.mid { grid-column: span 1; grid-row: span 1; }
      .cover-frame img, .story-main img, .scene-panel img, .news-feature img { height: 220px; }
      .hero-nav { left: 20px; right: auto; }
      .count-row { flex-wrap: wrap; }
    }
    @media (max-width: 520px) {
      .container, .container-wide { width: min(100% - 28px, var(--wrap)); }
      .hero-actions, .btn { width: 100%; }
      .prod-bar { grid-template-columns: 1fr; }
      .prod-bar div { border-right: 0; border-bottom: 1px solid var(--line); }
    }
    @media (prefers-reduced-motion: reduce) {
      html { scroll-behavior: auto; }
      .hero-track, .card, .btn, .drawer { transition: none; }
    }