/* roulang page: index */
:root {
      --brand: #2563EB;
      --brand-dark: #1D4ED8;
      --brand-soft: #EFF6FF;
      --cyan: #06B6D4;
      --amber: #F59E0B;
      --ink: #0F172A;
      --muted: #64748B;
      --subtle: #475569;
      --bg: #F8FBFF;
      --paper: #FFFFFF;
      --line: #E2E8F0;
      --radius-lg: 20px;
      --radius-xl: 24px;
      --shadow-soft: 0 18px 50px rgba(15, 23, 42, .08);
      --shadow-hover: 0 24px 70px rgba(37, 99, 235, .14);
      --nav-h: 72px;
      --font: system-ui, -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
    }

    * { box-sizing: border-box; }
    html { scroll-behavior: smooth; }
    body {
      margin: 0;
      font-family: var(--font);
      color: var(--ink);
      background:
        radial-gradient(circle at 12% 8%, rgba(37, 99, 235, .10), transparent 28%),
        radial-gradient(circle at 92% 18%, rgba(6, 182, 212, .12), transparent 24%),
        linear-gradient(180deg, #F8FBFF 0%, #FFFFFF 34%, #F8FAFC 100%);
      line-height: 1.75;
      text-rendering: optimizeLegibility;
      -webkit-font-smoothing: antialiased;
    }

    a { color: inherit; text-decoration: none; transition: color .2s ease, background-color .2s ease, border-color .2s ease, transform .2s ease; }
    img { max-width: 100%; display: block; }
    button { font-family: inherit; }
    ::selection { background: rgba(37, 99, 235, .18); color: var(--ink); }

    .site-container {
      width: min(100% - 40px, 1200px);
      margin-inline: auto;
    }

    .skip-link {
      position: absolute;
      left: -999px;
      top: 12px;
      z-index: 100;
      padding: 10px 14px;
      border-radius: 12px;
      background: var(--brand);
      color: white;
    }
    .skip-link:focus { left: 12px; outline: 3px solid rgba(37, 99, 235, .25); }

    .site-header {
      position: sticky;
      top: 0;
      z-index: 50;
      height: var(--nav-h);
      background: rgba(255, 255, 255, .92);
      border-bottom: 1px solid rgba(226, 232, 240, .85);
      backdrop-filter: blur(12px);
    }

    .nav-wrap {
      height: var(--nav-h);
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 24px;
    }

    .logo-mark {
      width: 38px;
      height: 38px;
      border-radius: 14px;
      background: linear-gradient(135deg, var(--brand), var(--cyan));
      box-shadow: 0 12px 28px rgba(37, 99, 235, .22);
      position: relative;
      flex: 0 0 auto;
    }
    .logo-mark::before {
      content: "";
      position: absolute;
      inset: 9px;
      border: 2px solid rgba(255,255,255,.86);
      border-radius: 9px;
    }
    .logo-mark::after {
      content: "";
      position: absolute;
      width: 8px;
      height: 8px;
      right: 7px;
      top: 7px;
      border-radius: 999px;
      background: #fff;
      box-shadow: 0 14px 0 rgba(255,255,255,.72);
    }

    .logo-text {
      display: flex;
      flex-direction: column;
      gap: 1px;
      min-width: 0;
    }
    .logo-title {
      font-weight: 800;
      letter-spacing: -.02em;
      font-size: 15px;
      line-height: 1.2;
      max-width: 320px;
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
    }
    .logo-sub {
      font-size: 12px;
      color: var(--muted);
      line-height: 1.2;
    }

    .desktop-nav {
      display: flex;
      align-items: center;
      gap: 10px;
      padding: 6px;
      border: 1px solid rgba(226, 232, 240, .8);
      border-radius: 999px;
      background: rgba(248, 250, 252, .72);
    }
    .nav-link {
      position: relative;
      padding: 8px 16px;
      border-radius: 999px;
      color: #334155;
      font-size: 14px;
      font-weight: 650;
    }
    .nav-link:hover,
    .nav-link.active {
      color: var(--brand-dark);
      background: #FFFFFF;
      box-shadow: 0 8px 22px rgba(15, 23, 42, .06);
    }
    .nav-link.active::after {
      content: "";
      position: absolute;
      left: 50%;
      bottom: 4px;
      width: 18px;
      height: 2px;
      transform: translateX(-50%);
      border-radius: 999px;
      background: var(--brand);
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      border-radius: 999px;
      padding: 12px 18px;
      font-weight: 750;
      font-size: 15px;
      border: 1px solid transparent;
      transition: transform .2s ease, box-shadow .2s ease, background-color .2s ease, border-color .2s ease, color .2s ease;
      cursor: pointer;
      line-height: 1.2;
      white-space: nowrap;
    }
    .btn:focus-visible,
    .nav-link:focus-visible,
    summary:focus-visible,
    a:focus-visible,
    button:focus-visible {
      outline: 3px solid rgba(37, 99, 235, .22);
      outline-offset: 3px;
    }
    .btn-primary {
      background: var(--brand);
      color: white;
      box-shadow: 0 14px 30px rgba(37, 99, 235, .20);
    }
    .btn-primary:hover {
      background: var(--brand-dark);
      transform: translateY(-2px);
      box-shadow: 0 18px 40px rgba(37, 99, 235, .28);
    }
    .btn-secondary {
      background: #fff;
      color: var(--brand-dark);
      border-color: #BFDBFE;
      box-shadow: 0 10px 24px rgba(15, 23, 42, .05);
    }
    .btn-secondary:hover {
      background: #EFF6FF;
      border-color: #93C5FD;
      transform: translateY(-2px);
    }

    .mobile-toggle {
      display: none;
      width: 42px;
      height: 42px;
      border: 1px solid var(--line);
      border-radius: 14px;
      background: #fff;
      color: var(--ink);
      align-items: center;
      justify-content: center;
    }
    .mobile-menu {
      display: none;
      position: absolute;
      left: 20px;
      right: 20px;
      top: 78px;
      padding: 14px;
      border: 1px solid var(--line);
      border-radius: 20px;
      background: #fff;
      box-shadow: var(--shadow-soft);
    }
    .mobile-menu.open { display: grid; gap: 10px; }
    .mobile-menu a { padding: 12px 14px; border-radius: 14px; font-weight: 700; color: #334155; }
    .mobile-menu a:hover { background: var(--brand-soft); color: var(--brand-dark); }

    .section {
      padding: 96px 0;
      position: relative;
    }
    .section-sm { padding: 72px 0; }
    .section-head {
      max-width: 760px;
      margin-bottom: 38px;
    }
    .section-head.center {
      margin-inline: auto;
      text-align: center;
    }
    .eyebrow,
    .badge {
      display: inline-flex;
      align-items: center;
      gap: 7px;
      border-radius: 999px;
      padding: 7px 12px;
      font-size: 13px;
      font-weight: 800;
      color: var(--brand-dark);
      background: #EFF6FF;
      border: 1px solid #BFDBFE;
      line-height: 1;
    }
    .eyebrow::before {
      content: "";
      width: 7px;
      height: 7px;
      border-radius: 999px;
      background: var(--cyan);
      box-shadow: 0 0 0 4px rgba(6, 182, 212, .12);
    }
    .section-title {
      margin: 14px 0 12px;
      font-size: clamp(28px, 4vw, 42px);
      line-height: 1.15;
      letter-spacing: -.04em;
      font-weight: 850;
      color: var(--ink);
    }
    .section-desc {
      color: var(--muted);
      font-size: 17px;
      line-height: 1.8;
    }

    .hero {
      padding: 84px 0 56px;
      overflow: hidden;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: minmax(0, 1.04fr) minmax(360px, .96fr);
      gap: 54px;
      align-items: center;
    }
    .hero h1 {
      margin: 20px 0 20px;
      font-size: clamp(36px, 5.2vw, 64px);
      line-height: 1.06;
      letter-spacing: -.055em;
      font-weight: 900;
    }
    .hero-lead {
      max-width: 680px;
      color: var(--subtle);
      font-size: 18px;
      line-height: 1.9;
    }
    .hero-actions {
      display: flex;
      gap: 14px;
      flex-wrap: wrap;
      margin-top: 30px;
    }
    .trust-points {
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      gap: 12px;
      margin-top: 30px;
    }
    .trust-point {
      display: flex;
      align-items: center;
      gap: 9px;
      padding: 12px 14px;
      border: 1px solid var(--line);
      border-radius: 16px;
      background: rgba(255,255,255,.78);
      color: #334155;
      font-weight: 700;
      font-size: 14px;
    }
    .check-dot {
      width: 18px;
      height: 18px;
      border-radius: 999px;
      background: rgba(6, 182, 212, .14);
      color: #0891B2;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-size: 12px;
      flex: 0 0 auto;
    }

    .product-panel {
      position: relative;
      border: 1px solid rgba(148, 163, 184, .28);
      border-radius: 30px;
      background: linear-gradient(180deg, rgba(255,255,255,.96), rgba(248,251,255,.96));
      box-shadow: var(--shadow-soft);
      padding: 18px;
      isolation: isolate;
    }
    .product-panel::before {
      content: "";
      position: absolute;
      inset: -28px;
      z-index: -1;
      background:
        linear-gradient(rgba(37,99,235,.08) 1px, transparent 1px),
        linear-gradient(90deg, rgba(37,99,235,.08) 1px, transparent 1px);
      background-size: 28px 28px;
      mask-image: radial-gradient(circle, #000 0%, transparent 70%);
      opacity: .55;
    }
    .panel-top {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 14px 14px 18px;
    }
    .traffic-lights { display: flex; gap: 6px; }
    .traffic-lights span { width: 9px; height: 9px; border-radius: 999px; background: #CBD5E1; }
    .traffic-lights span:nth-child(1) { background: #60A5FA; }
    .traffic-lights span:nth-child(2) { background: #22D3EE; }
    .traffic-lights span:nth-child(3) { background: #FBBF24; }
    .status-pill {
      padding: 6px 10px;
      border-radius: 999px;
      background: #ECFEFF;
      color: #0E7490;
      font-weight: 800;
      font-size: 12px;
    }
    .panel-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 14px;
    }
    .metric-card,
    .review-card,
    .chart-card {
      border: 1px solid var(--line);
      border-radius: 22px;
      background: #fff;
      padding: 16px;
    }
    .metric-card strong {
      display: block;
      font-size: 28px;
      line-height: 1;
      letter-spacing: -.04em;
      margin-top: 8px;
    }
    .metric-card p,
    .review-card p,
    .chart-card p { color: var(--muted); font-size: 13px; margin: 0; }
    .review-card { grid-column: span 2; }
    .review-row {
      display: grid;
      grid-template-columns: 1fr auto;
      gap: 12px;
      align-items: center;
      padding: 11px 0;
      border-bottom: 1px solid #F1F5F9;
    }
    .review-row:last-child { border-bottom: 0; }
    .bar {
      height: 8px;
      border-radius: 999px;
      background: #E2E8F0;
      overflow: hidden;
      margin-top: 10px;
    }
    .bar span {
      display: block;
      height: 100%;
      border-radius: inherit;
      background: linear-gradient(90deg, var(--brand), var(--cyan));
    }

    .stats-card {
      display: grid;
      grid-template-columns: repeat(4, minmax(0, 1fr));
      border: 1px solid var(--line);
      border-radius: 28px;
      background: rgba(255,255,255,.92);
      box-shadow: var(--shadow-soft);
      overflow: hidden;
    }
    .stat-item {
      padding: 28px;
      border-right: 1px solid var(--line);
    }
    .stat-item:last-child { border-right: 0; }
    .stat-k {
      display: block;
      color: var(--brand-dark);
      font-size: 30px;
      font-weight: 900;
      letter-spacing: -.04em;
      line-height: 1;
    }
    .stat-v {
      margin-top: 10px;
      color: var(--subtle);
      font-weight: 700;
    }
    .stat-note {
      margin-top: 6px;
      color: var(--muted);
      font-size: 13px;
      line-height: 1.6;
    }

    .feature-layout {
      display: grid;
      grid-template-columns: .84fr 1.16fr;
      gap: 28px;
      align-items: stretch;
    }
    .feature-intro {
      border-radius: 28px;
      border: 1px solid #BFDBFE;
      background:
        radial-gradient(circle at top right, rgba(6,182,212,.16), transparent 34%),
        linear-gradient(180deg, #EFF6FF, #FFFFFF);
      padding: 34px;
      box-shadow: var(--shadow-soft);
      min-height: 100%;
    }
    .feature-intro ul {
      display: grid;
      gap: 13px;
      margin: 28px 0 0;
      padding: 0;
      list-style: none;
    }
    .feature-intro li {
      display: flex;
      gap: 10px;
      align-items: flex-start;
      color: #334155;
      font-weight: 650;
    }
    .feature-grid {
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 18px;
    }
    .card {
      border: 1px solid var(--line);
      border-radius: 24px;
      background: #fff;
      box-shadow: 0 12px 32px rgba(15, 23, 42, .05);
      transition: transform .22s ease, box-shadow .22s ease, border-color .22s ease;
    }
    .card:hover {
      transform: translateY(-4px);
      border-color: #93C5FD;
      box-shadow: var(--shadow-hover);
    }
    .feature-card {
      padding: 24px;
    }
    .icon-box {
      width: 46px;
      height: 46px;
      border-radius: 16px;
      background: linear-gradient(135deg, #EFF6FF, #ECFEFF);
      color: var(--brand);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 18px;
      border: 1px solid #BFDBFE;
    }
    .feature-card h3,
    .scenario-card h3,
    .pricing-card h3 {
      margin: 0 0 10px;
      font-size: 21px;
      line-height: 1.3;
      font-weight: 850;
      letter-spacing: -.02em;
    }
    .feature-card p,
    .scenario-card p,
    .pricing-card p {
      margin: 0;
      color: var(--muted);
      font-size: 15px;
      line-height: 1.75;
    }
    .tag-row {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
      margin-top: 18px;
    }
    .tag {
      padding: 5px 9px;
      border-radius: 999px;
      background: #F8FAFC;
      border: 1px solid var(--line);
      color: #475569;
      font-size: 12px;
      font-weight: 750;
    }

    .scenario-wrap {
      display: grid;
      grid-template-columns: .9fr 1.1fr;
      gap: 38px;
      align-items: center;
    }
    .flow-line {
      position: relative;
      display: grid;
      gap: 16px;
    }
    .flow-line::before {
      content: "";
      position: absolute;
      left: 22px;
      top: 24px;
      bottom: 24px;
      width: 2px;
      background: linear-gradient(180deg, #BFDBFE, #67E8F9);
    }
    .flow-item {
      position: relative;
      display: grid;
      grid-template-columns: 46px 1fr;
      gap: 16px;
      align-items: start;
      padding: 18px;
      border: 1px solid var(--line);
      border-radius: 22px;
      background: rgba(255,255,255,.88);
      box-shadow: 0 10px 28px rgba(15, 23, 42, .04);
    }
    .flow-num {
      width: 46px;
      height: 46px;
      border-radius: 16px;
      background: var(--brand);
      color: #fff;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 900;
      box-shadow: 0 12px 26px rgba(37,99,235,.22);
      z-index: 2;
    }
    .flow-item h3 { margin: 0 0 6px; font-size: 18px; font-weight: 850; }
    .flow-item p { margin: 0; color: var(--muted); font-size: 14px; line-height: 1.7; }
    .scenario-card {
      padding: 32px;
      background:
        linear-gradient(135deg, rgba(255,255,255,.94), rgba(239,246,255,.86)),
        linear-gradient(rgba(37,99,235,.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(37,99,235,.05) 1px, transparent 1px);
      background-size: auto, 24px 24px, 24px 24px;
    }

    .case-grid {
      display: grid;
      grid-template-columns: 1.45fr .85fr;
      gap: 20px;
    }
    .case-main {
      padding: 34px;
      border-radius: 28px;
      border: 1px solid #BFDBFE;
      background: linear-gradient(135deg, #EFF6FF, #FFFFFF 62%);
      box-shadow: var(--shadow-soft);
    }
    .case-main h3 { font-size: 26px; margin: 10px 0 16px; font-weight: 900; letter-spacing: -.03em; }
    .case-blocks {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 12px;
      margin-top: 24px;
    }
    .case-block {
      padding: 16px;
      border-radius: 18px;
      background: #fff;
      border: 1px solid var(--line);
    }
    .case-block strong { display: block; margin-bottom: 6px; }
    .case-block span { color: var(--muted); font-size: 13px; line-height: 1.65; }
    .case-side {
      display: grid;
      gap: 20px;
    }
    .mini-result {
      padding: 26px;
      border-radius: 26px;
      border: 1px solid var(--line);
      background: #fff;
      box-shadow: 0 12px 32px rgba(15,23,42,.05);
    }
    .mini-result strong {
      display: block;
      color: var(--brand-dark);
      font-size: 32px;
      font-weight: 950;
      line-height: 1;
      margin-bottom: 12px;
    }

    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      gap: 20px;
      align-items: stretch;
    }
    .pricing-card {
      position: relative;
      padding: 28px;
      border-radius: 28px;
      border: 1px solid var(--line);
      background: #fff;
      box-shadow: 0 12px 32px rgba(15,23,42,.05);
      transition: transform .22s ease, box-shadow .22s ease, border-color .22s ease;
    }
    .pricing-card:hover {
      transform: translateY(-4px);
      border-color: #93C5FD;
      box-shadow: var(--shadow-hover);
    }
    .pricing-card.recommended {
      border: 2px solid var(--brand);
      box-shadow: 0 24px 70px rgba(37,99,235,.15);
      transform: translateY(-6px);
    }
    .recommended .recommend-badge {
      position: absolute;
      right: 22px;
      top: 22px;
      background: var(--brand);
      color: #fff;
      border-color: var(--brand);
    }
    .price {
      margin: 22px 0;
      font-size: 30px;
      font-weight: 950;
      letter-spacing: -.04em;
      color: var(--ink);
    }
    .pricing-list {
      list-style: none;
      padding: 0;
      margin: 22px 0 26px;
      display: grid;
      gap: 12px;
    }
    .pricing-list li {
      display: flex;
      gap: 10px;
      align-items: flex-start;
      color: #334155;
      font-size: 15px;
    }

    .news-area {
      border-radius: 34px;
      background:
        radial-gradient(circle at top left, rgba(37,99,235,.10), transparent 30%),
        linear-gradient(180deg, #F8FBFF, #FFFFFF);
      border: 1px solid var(--line);
      padding: 34px;
      box-shadow: var(--shadow-soft);
    }
    .news-grid {
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      gap: 18px;
    }
    .news-card {
      display: flex;
      flex-direction: column;
      min-height: 252px;
      padding: 22px;
      border-radius: 24px;
      border: 1px solid var(--line);
      background: #fff;
      box-shadow: 0 10px 26px rgba(15,23,42,.04);
      transition: transform .22s ease, box-shadow .22s ease, border-color .22s ease;
    }
    .news-card:hover {
      transform: translateY(-3px);
      border-color: #93C5FD;
      box-shadow: var(--shadow-hover);
    }
    .news-meta {
      display: flex;
      justify-content: space-between;
      gap: 12px;
      align-items: center;
      margin-bottom: 15px;
    }
    .news-date {
      color: var(--muted);
      font-size: 13px;
      white-space: nowrap;
    }
    .news-title {
      font-size: 19px;
      font-weight: 850;
      line-height: 1.45;
      letter-spacing: -.02em;
      margin-bottom: 12px;
    }
    .news-card:hover .news-title { color: var(--brand-dark); }
    .news-summary {
      color: var(--muted);
      font-size: 14px;
      line-height: 1.8;
      flex: 1;
    }
    .read-more {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      margin-top: 18px;
      color: var(--brand-dark);
      font-weight: 800;
      font-size: 14px;
    }
    .empty-state {
      border: 1px dashed #93C5FD;
      border-radius: 26px;
      background: rgba(239,246,255,.72);
      padding: 34px;
      text-align: center;
      color: var(--subtle);
    }
    .empty-icon {
      width: 54px;
      height: 54px;
      border-radius: 20px;
      background: #fff;
      border: 1px solid #BFDBFE;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      color: var(--brand);
      margin-bottom: 14px;
      box-shadow: 0 12px 26px rgba(37,99,235,.10);
    }

    .faq-grid {
      display: grid;
      grid-template-columns: .85fr 1.15fr;
      gap: 34px;
      align-items: start;
    }
    .faq-list {
      display: grid;
      gap: 14px;
    }
    details.faq-item {
      border: 1px solid var(--line);
      border-radius: 22px;
      background: #fff;
      box-shadow: 0 10px 26px rgba(15,23,42,.04);
      overflow: hidden;
      transition: border-color .2s ease, background-color .2s ease;
    }
    details.faq-item[open] {
      border-color: #93C5FD;
      background: #F8FBFF;
    }
    .faq-item summary {
      cursor: pointer;
      list-style: none;
      padding: 20px 22px;
      font-weight: 850;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 18px;
    }
    .faq-item summary::-webkit-details-marker { display: none; }
    .faq-item summary::after {
      content: "+";
      width: 26px;
      height: 26px;
      border-radius: 999px;
      background: #EFF6FF;
      color: var(--brand-dark);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      flex: 0 0 auto;
      font-weight: 900;
    }
    .faq-item[open] summary::after { content: "−"; }
    .faq-item p {
      margin: 0;
      padding: 0 22px 22px;
      color: var(--muted);
      line-height: 1.8;
    }

    .cta-card {
      position: relative;
      overflow: hidden;
      border-radius: 34px;
      border: 1px solid #BFDBFE;
      background:
        radial-gradient(circle at 88% 22%, rgba(6,182,212,.18), transparent 26%),
        linear-gradient(135deg, #EFF6FF, #FFFFFF 55%, #ECFEFF);
      padding: 46px;
      box-shadow: var(--shadow-soft);
    }
    .cta-card::after {
      content: "";
      position: absolute;
      inset: 0;
      background:
        linear-gradient(rgba(37,99,235,.06) 1px, transparent 1px),
        linear-gradient(90deg, rgba(37,99,235,.06) 1px, transparent 1px);
      background-size: 30px 30px;
      opacity: .6;
      pointer-events: none;
      mask-image: linear-gradient(90deg, transparent, #000 42%, #000);
    }
    .cta-inner {
      position: relative;
      z-index: 1;
      display: grid;
      grid-template-columns: 1fr auto;
      gap: 30px;
      align-items: center;
    }
    .cta-card h2 {
      margin: 0 0 12px;
      font-size: clamp(28px, 4vw, 42px);
      line-height: 1.16;
      font-weight: 900;
      letter-spacing: -.04em;
    }
    .cta-card p {
      margin: 0;
      color: var(--subtle);
      max-width: 760px;
      font-size: 17px;
      line-height: 1.85;
    }
    .cta-actions { display: flex; gap: 12px; flex-wrap: wrap; }

    .site-footer {
      border-top: 1px solid var(--line);
      background: #FFFFFF;
      padding: 56px 0 28px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 1.25fr .75fr .75fr;
      gap: 36px;
    }
    .footer-brand p {
      margin: 16px 0 0;
      color: var(--muted);
      max-width: 520px;
    }
    .footer-title {
      font-weight: 850;
      margin-bottom: 14px;
      color: var(--ink);
    }
    .footer-links {
      display: grid;
      gap: 10px;
    }
    .footer-links a,
    .footer-links span {
      color: var(--muted);
      font-size: 14px;
    }
    .footer-links a:hover { color: var(--brand-dark); }
    .footer-bottom {
      margin-top: 34px;
      padding-top: 22px;
      border-top: 1px solid var(--line);
      display: flex;
      justify-content: space-between;
      gap: 16px;
      flex-wrap: wrap;
      color: var(--muted);
      font-size: 13px;
    }

    @media (max-width: 1024px) {
      .hero-grid,
      .feature-layout,
      .scenario-wrap,
      .case-grid,
      .faq-grid {
        grid-template-columns: 1fr;
      }
      .stats-card,
      .pricing-grid,
      .news-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
      }
      .case-blocks { grid-template-columns: 1fr; }
      .pricing-card.recommended { transform: none; }
      .desktop-nav { display: none; }
      .mobile-toggle { display: inline-flex; }
    }

    @media (max-width: 768px) {
      :root { --nav-h: 66px; }
      .site-container { width: min(100% - 28px, 1200px); }
      .hero { padding: 58px 0 36px; }
      .section { padding: 68px 0; }
      .section-sm { padding: 54px 0; }
      .hero-grid { gap: 34px; }
      .hero-actions,
      .cta-actions { flex-direction: column; }
      .btn { width: 100%; }
      .trust-points,
      .stats-card,
      .feature-grid,
      .pricing-grid,
      .news-grid,
      .panel-grid,
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .review-card { grid-column: span 1; }
      .stat-item {
        border-right: 0;
        border-bottom: 1px solid var(--line);
      }
      .stat-item:last-child { border-bottom: 0; }
      .news-area,
      .cta-card,
      .feature-intro,
      .case-main {
        padding: 24px;
        border-radius: 26px;
      }
      .cta-inner { grid-template-columns: 1fr; }
      .footer-bottom { flex-direction: column; }
      .logo-title { max-width: 210px; }
    }

    @media (max-width: 520px) {
      .logo-sub { display: none; }
      .logo-title { max-width: 178px; font-size: 14px; }
      .hero h1 { font-size: 38px; }
      .hero-lead, .section-desc, .cta-card p { font-size: 16px; }
      .product-panel { padding: 12px; border-radius: 24px; }
      .flow-item { grid-template-columns: 40px 1fr; padding: 14px; }
      .flow-num { width: 40px; height: 40px; border-radius: 14px; }
      .mobile-menu { left: 14px; right: 14px; }
    }

/* roulang page: article */
:root {
      --brand: #2563eb;
      --brand-dark: #1d4ed8;
      --brand-soft: #dbeafe;
      --cyan: #06b6d4;
      --amber: #f59e0b;
      --ink: #0f172a;
      --muted: #475569;
      --soft-muted: #64748b;
      --line: #e2e8f0;
      --bg: #f8fbff;
      --bg-2: #f8fafc;
      --card: #ffffff;
      --radius-sm: 12px;
      --radius: 18px;
      --radius-lg: 24px;
      --shadow: 0 16px 45px rgba(15, 23, 42, .08);
      --shadow-hover: 0 24px 60px rgba(37, 99, 235, .14);
      --font: system-ui, -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
    }

    * {
      box-sizing: border-box;
    }

    html {
      scroll-behavior: smooth;
      text-size-adjust: 100%;
    }

    body {
      margin: 0;
      min-height: 100vh;
      font-family: var(--font);
      color: var(--ink);
      background:
        radial-gradient(circle at 10% 0%, rgba(37, 99, 235, .10), transparent 34rem),
        radial-gradient(circle at 90% 12%, rgba(6, 182, 212, .10), transparent 30rem),
        linear-gradient(180deg, #ffffff 0%, var(--bg) 42%, #ffffff 100%);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

    a {
      color: inherit;
      text-decoration: none;
      transition: color .2s ease, background-color .2s ease, border-color .2s ease, transform .2s ease, box-shadow .2s ease;
    }

    img {
      display: block;
      max-width: 100%;
      height: auto;
    }

    button {
      font-family: inherit;
    }

    ::selection {
      background: rgba(37, 99, 235, .16);
      color: var(--ink);
    }

    .site-container {
      width: min(100% - 40px, 1180px);
      margin-inline: auto;
    }

    .site-header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(255, 255, 255, .94);
      border-bottom: 1px solid rgba(226, 232, 240, .88);
      backdrop-filter: blur(14px);
    }

    .nav-wrap {
      height: 72px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 22px;
      position: relative;
    }

    .logo-mark {
      width: 40px;
      height: 40px;
      flex: 0 0 auto;
      border-radius: 14px;
      position: relative;
      background:
        linear-gradient(135deg, rgba(37, 99, 235, .98), rgba(6, 182, 212, .88)),
        radial-gradient(circle at 35% 30%, rgba(255, 255, 255, .72), transparent 32%);
      box-shadow: 0 12px 26px rgba(37, 99, 235, .22);
    }

    .logo-mark::before {
      content: "";
      position: absolute;
      inset: 9px;
      border: 2px solid rgba(255, 255, 255, .86);
      border-radius: 10px 10px 13px 13px;
      clip-path: polygon(50% 0, 100% 18%, 90% 78%, 50% 100%, 10% 78%, 0 18%);
    }

    .logo-mark::after {
      content: "";
      position: absolute;
      width: 8px;
      height: 8px;
      right: 8px;
      bottom: 8px;
      border-radius: 999px;
      background: #fff;
      box-shadow: -11px -10px 0 rgba(255, 255, 255, .76);
    }

    .logo-text {
      display: grid;
      gap: 1px;
      min-width: 0;
    }

    .logo-title {
      color: var(--ink);
      font-weight: 800;
      letter-spacing: -.02em;
      line-height: 1.15;
      white-space: nowrap;
    }

    .logo-sub {
      color: var(--soft-muted);
      font-size: 12px;
      line-height: 1.2;
      white-space: nowrap;
    }

    .desktop-nav {
      display: flex;
      align-items: center;
      gap: 8px;
      margin-left: auto;
    }

    .nav-link {
      position: relative;
      display: inline-flex;
      align-items: center;
      height: 40px;
      padding: 0 14px;
      color: var(--muted);
      font-size: 15px;
      font-weight: 600;
      border-radius: 999px;
    }

    .nav-link:hover,
    .nav-link:focus-visible {
      color: var(--brand);
      background: rgba(37, 99, 235, .06);
      outline: none;
    }

    .nav-link.active {
      color: var(--brand-dark);
      background: rgba(37, 99, 235, .08);
    }

    .nav-link.active::after {
      content: "";
      position: absolute;
      left: 18px;
      right: 18px;
      bottom: 5px;
      height: 2px;
      border-radius: 999px;
      background: var(--brand);
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      min-height: 44px;
      padding: 0 18px;
      border-radius: 999px;
      font-size: 15px;
      font-weight: 700;
      line-height: 1;
      border: 1px solid transparent;
      cursor: pointer;
      transition: transform .2s ease, box-shadow .2s ease, background-color .2s ease, border-color .2s ease, color .2s ease;
    }

    .btn:focus-visible,
    .mobile-toggle:focus-visible,
    summary:focus-visible {
      outline: 3px solid rgba(37, 99, 235, .24);
      outline-offset: 3px;
    }

    .btn-primary {
      color: #fff;
      background: var(--brand);
      box-shadow: 0 14px 28px rgba(37, 99, 235, .22);
    }

    .btn-primary:hover {
      transform: translateY(-2px);
      background: var(--brand-dark);
      box-shadow: 0 18px 36px rgba(37, 99, 235, .28);
    }

    .btn-secondary {
      color: var(--brand-dark);
      background: #fff;
      border-color: rgba(37, 99, 235, .22);
      box-shadow: 0 10px 22px rgba(15, 23, 42, .04);
    }

    .btn-secondary:hover {
      transform: translateY(-2px);
      background: rgba(37, 99, 235, .06);
      border-color: rgba(37, 99, 235, .36);
    }

    .mobile-toggle {
      width: 44px;
      height: 44px;
      display: none;
      align-items: center;
      justify-content: center;
      border: 1px solid var(--line);
      color: var(--ink);
      background: #fff;
      border-radius: 14px;
      box-shadow: 0 10px 20px rgba(15, 23, 42, .04);
      cursor: pointer;
    }

    .mobile-menu {
      display: none;
      position: absolute;
      top: calc(100% + 12px);
      left: 0;
      right: 0;
      padding: 12px;
      border: 1px solid var(--line);
      border-radius: 20px;
      background: rgba(255, 255, 255, .98);
      box-shadow: var(--shadow);
    }

    .mobile-menu a {
      display: flex;
      align-items: center;
      min-height: 46px;
      padding: 0 14px;
      border-radius: 14px;
      color: var(--muted);
      font-weight: 700;
    }

    .mobile-menu a:hover {
      color: var(--brand);
      background: rgba(37, 99, 235, .07);
    }

    .mobile-menu.is-open {
      display: grid;
      gap: 4px;
    }

    .article-hero {
      position: relative;
      overflow: hidden;
      padding: 56px 0 66px;
      background:
        linear-gradient(180deg, rgba(248, 251, 255, .96), rgba(255, 255, 255, .78)),
        radial-gradient(circle at 18% 20%, rgba(37, 99, 235, .13), transparent 30rem),
        radial-gradient(circle at 82% 8%, rgba(6, 182, 212, .12), transparent 26rem);
      border-bottom: 1px solid rgba(226, 232, 240, .72);
    }

    .article-hero::before {
      content: "";
      position: absolute;
      inset: 0;
      pointer-events: none;
      opacity: .42;
      background-image:
        linear-gradient(rgba(37, 99, 235, .08) 1px, transparent 1px),
        linear-gradient(90deg, rgba(37, 99, 235, .08) 1px, transparent 1px);
      background-size: 34px 34px;
      mask-image: linear-gradient(to bottom, rgba(0,0,0,.72), transparent);
    }

    .article-head {
      position: relative;
      max-width: 920px;
    }

    .breadcrumb {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 8px;
      margin-bottom: 24px;
      color: var(--soft-muted);
      font-size: 14px;
      font-weight: 600;
    }

    .breadcrumb a:hover {
      color: var(--brand);
    }

    .breadcrumb-sep {
      color: #94a3b8;
    }

    .badge {
      display: inline-flex;
      align-items: center;
      gap: 7px;
      width: fit-content;
      padding: 7px 12px;
      border-radius: 999px;
      color: var(--brand-dark);
      background: rgba(37, 99, 235, .08);
      border: 1px solid rgba(37, 99, 235, .14);
      font-size: 13px;
      font-weight: 800;
      line-height: 1;
    }

    .badge::before {
      content: "";
      width: 7px;
      height: 7px;
      border-radius: 999px;
      background: var(--cyan);
      box-shadow: 0 0 0 4px rgba(6, 182, 212, .12);
    }

    .article-title {
      margin: 18px 0 18px;
      max-width: 900px;
      color: var(--ink);
      font-size: clamp(30px, 5vw, 52px);
      line-height: 1.16;
      letter-spacing: -.045em;
      font-weight: 850;
    }

    .article-desc {
      max-width: 820px;
      color: var(--muted);
      font-size: 18px;
      line-height: 1.85;
      margin: 0;
    }

    .article-meta {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 12px;
      margin-top: 26px;
      color: var(--soft-muted);
      font-size: 14px;
      font-weight: 650;
    }

    .meta-pill {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 8px 12px;
      border-radius: 999px;
      background: rgba(255, 255, 255, .78);
      border: 1px solid rgba(226, 232, 240, .9);
      box-shadow: 0 10px 20px rgba(15, 23, 42, .035);
    }

    .meta-dot {
      width: 6px;
      height: 6px;
      border-radius: 999px;
      background: var(--brand);
    }

    .main-section {
      padding: 64px 0 92px;
    }

    .article-layout {
      display: grid;
      grid-template-columns: minmax(0, 1fr) 300px;
      gap: 34px;
      align-items: start;
    }

    .article-card {
      background: rgba(255, 255, 255, .94);
      border: 1px solid rgba(226, 232, 240, .92);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow);
      overflow: hidden;
    }

    .article-body {
      padding: clamp(24px, 4vw, 46px);
    }

    .prose-content {
      color: #1e293b;
      font-size: 17px;
      line-height: 1.86;
      word-break: break-word;
    }

    .prose-content > *:first-child {
      margin-top: 0;
    }

    .prose-content > *:last-child {
      margin-bottom: 0;
    }

    .prose-content p {
      margin: 1.08em 0;
    }

    .prose-content h2 {
      position: relative;
      margin: 2.1em 0 .85em;
      padding-left: 16px;
      color: var(--ink);
      font-size: clamp(26px, 3vw, 32px);
      line-height: 1.28;
      font-weight: 820;
      letter-spacing: -.03em;
    }

    .prose-content h2::before {
      content: "";
      position: absolute;
      left: 0;
      top: .18em;
      bottom: .18em;
      width: 4px;
      border-radius: 999px;
      background: linear-gradient(180deg, var(--brand), var(--cyan));
    }

    .prose-content h3 {
      margin: 1.7em 0 .72em;
      color: var(--ink);
      font-size: clamp(21px, 2.3vw, 24px);
      line-height: 1.35;
      font-weight: 800;
      letter-spacing: -.02em;
    }

    .prose-content h4 {
      margin: 1.45em 0 .6em;
      color: var(--ink);
      font-size: 19px;
      font-weight: 800;
    }

    .prose-content a {
      color: var(--brand-dark);
      font-weight: 700;
      text-decoration: underline;
      text-decoration-color: rgba(37, 99, 235, .32);
      text-underline-offset: 4px;
    }

    .prose-content a:hover {
      color: var(--brand);
      text-decoration-color: var(--brand);
    }

    .prose-content ul,
    .prose-content ol {
      margin: 1.1em 0;
      padding-left: 1.45em;
    }

    .prose-content li {
      margin: .55em 0;
      padding-left: .18em;
    }

    .prose-content ul li::marker {
      color: var(--brand);
    }

    .prose-content ol li::marker {
      color: var(--brand-dark);
      font-weight: 800;
    }

    .prose-content blockquote {
      margin: 1.5em 0;
      padding: 20px 22px;
      border-left: 4px solid var(--brand);
      border-radius: 18px;
      color: #334155;
      background: linear-gradient(135deg, rgba(219, 234, 254, .78), rgba(240, 249, 255, .88));
      box-shadow: inset 0 0 0 1px rgba(37, 99, 235, .08);
    }

    .prose-content blockquote p {
      margin: .4em 0;
    }

    .prose-content img {
      margin: 1.6em auto;
      border-radius: 20px;
      border: 1px solid rgba(226, 232, 240, .9);
      box-shadow: 0 18px 45px rgba(15, 23, 42, .10);
    }

    .prose-content figure {
      margin: 1.8em 0;
    }

    .prose-content figcaption {
      margin-top: 10px;
      color: var(--soft-muted);
      font-size: 14px;
      text-align: center;
    }

    .prose-content table {
      width: 100%;
      margin: 1.5em 0;
      border-collapse: separate;
      border-spacing: 0;
      overflow: hidden;
      border: 1px solid var(--line);
      border-radius: 16px;
      display: block;
      max-width: 100%;
      overflow-x: auto;
      background: #fff;
    }

    .prose-content thead {
      background: #f1f5f9;
    }

    .prose-content th,
    .prose-content td {
      min-width: 140px;
      padding: 13px 15px;
      border-bottom: 1px solid var(--line);
      text-align: left;
      vertical-align: top;
      font-size: 15px;
    }

    .prose-content th {
      color: var(--ink);
      font-weight: 800;
    }

    .prose-content tr:last-child td {
      border-bottom: 0;
    }

    .prose-content code {
      padding: .18em .42em;
      border-radius: 8px;
      color: #0f766e;
      background: rgba(20, 184, 166, .10);
      font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
      font-size: .92em;
    }

    .prose-content pre {
      margin: 1.55em 0;
      padding: 18px;
      overflow-x: auto;
      border-radius: 18px;
      color: #dbeafe;
      background: #0f172a;
      box-shadow: 0 18px 42px rgba(15, 23, 42, .18);
    }

    .prose-content pre code {
      padding: 0;
      color: inherit;
      background: transparent;
      font-size: 14px;
    }

    .empty-state {
      padding: 34px;
      border: 1px dashed rgba(37, 99, 235, .34);
      border-radius: 22px;
      background: linear-gradient(135deg, rgba(219, 234, 254, .42), rgba(255, 255, 255, .86));
      text-align: center;
    }

    .empty-icon {
      width: 58px;
      height: 58px;
      display: inline-grid;
      place-items: center;
      margin-bottom: 16px;
      border-radius: 20px;
      color: var(--brand);
      background: rgba(37, 99, 235, .09);
    }

    .empty-state h2 {
      margin: 0 0 8px;
      color: var(--ink);
      font-size: 24px;
      font-weight: 820;
    }

    .empty-state p {
      margin: 0 0 22px;
      color: var(--muted);
    }

    .side-panel {
      position: sticky;
      top: 96px;
      display: grid;
      gap: 18px;
    }

    .side-card {
      padding: 22px;
      border: 1px solid rgba(226, 232, 240, .95);
      border-radius: 22px;
      background: rgba(255, 255, 255, .92);
      box-shadow: 0 14px 38px rgba(15, 23, 42, .06);
    }

    .side-card h2,
    .side-card h3 {
      margin: 0 0 12px;
      color: var(--ink);
      font-size: 18px;
      line-height: 1.35;
      font-weight: 820;
    }

    .side-card p {
      margin: 0;
      color: var(--muted);
      font-size: 14px;
      line-height: 1.75;
    }

    .strategy-list {
      display: grid;
      gap: 10px;
      margin-top: 16px;
    }

    .strategy-list span {
      display: flex;
      align-items: flex-start;
      gap: 9px;
      color: #334155;
      font-size: 14px;
      font-weight: 650;
    }

    .strategy-list span::before {
      content: "";
      width: 8px;
      height: 8px;
      margin-top: 8px;
      flex: 0 0 auto;
      border-radius: 999px;
      background: var(--cyan);
      box-shadow: 0 0 0 4px rgba(6, 182, 212, .10);
    }

    .return-panel {
      margin-top: 28px;
      padding: 24px;
      border: 1px solid rgba(226, 232, 240, .95);
      border-radius: 22px;
      background:
        linear-gradient(135deg, rgba(248, 251, 255, .98), rgba(255, 255, 255, .98)),
        radial-gradient(circle at 0 0, rgba(37, 99, 235, .10), transparent 18rem);
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 18px;
    }

    .return-panel h2 {
      margin: 0 0 6px;
      color: var(--ink);
      font-size: 20px;
      font-weight: 820;
    }

    .return-panel p {
      margin: 0;
      color: var(--muted);
      font-size: 15px;
    }

    .cta-strip {
      margin-top: 34px;
      padding: clamp(24px, 4vw, 34px);
      border-radius: 28px;
      border: 1px solid rgba(37, 99, 235, .12);
      background:
        linear-gradient(135deg, rgba(219, 234, 254, .74), rgba(236, 254, 255, .62)),
        radial-gradient(circle at 88% 20%, rgba(6, 182, 212, .22), transparent 15rem);
      box-shadow: 0 20px 50px rgba(37, 99, 235, .10);
      overflow: hidden;
      position: relative;
    }

    .cta-strip::after {
      content: "";
      position: absolute;
      inset: 0;
      pointer-events: none;
      opacity: .36;
      background-image:
        linear-gradient(rgba(37, 99, 235, .11) 1px, transparent 1px),
        linear-gradient(90deg, rgba(37, 99, 235, .11) 1px, transparent 1px);
      background-size: 28px 28px;
      mask-image: linear-gradient(90deg, transparent, #000 30%, #000 70%, transparent);
    }

    .cta-inner {
      position: relative;
      z-index: 1;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 24px;
    }

    .cta-strip h2 {
      margin: 0 0 8px;
      color: var(--ink);
      font-size: clamp(24px, 3vw, 32px);
      line-height: 1.25;
      font-weight: 850;
      letter-spacing: -.03em;
    }

    .cta-strip p {
      margin: 0;
      max-width: 680px;
      color: var(--muted);
      font-size: 16px;
    }

    .site-footer {
      padding: 58px 0 26px;
      background: #ffffff;
      border-top: 1px solid rgba(226, 232, 240, .92);
    }

    .footer-grid {
      display: grid;
      grid-template-columns: minmax(0, 1.4fr) minmax(180px, .7fr) minmax(220px, .8fr);
      gap: 34px;
      align-items: start;
    }

    .footer-brand p {
      max-width: 520px;
      margin: 18px 0 0;
      color: var(--muted);
      font-size: 15px;
      line-height: 1.85;
    }

    .footer-title {
      margin-bottom: 14px;
      color: var(--ink);
      font-size: 15px;
      font-weight: 850;
    }

    .footer-links {
      display: grid;
      gap: 10px;
      color: var(--soft-muted);
      font-size: 14px;
      font-weight: 600;
    }

    .footer-links a:hover {
      color: var(--brand);
      transform: translateX(2px);
    }

    .footer-bottom {
      margin-top: 38px;
      padding-top: 20px;
      border-top: 1px solid rgba(226, 232, 240, .82);
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 14px;
      flex-wrap: wrap;
      color: #64748b;
      font-size: 13px;
    }

    @media (max-width: 1024px) {
      .article-layout {
        grid-template-columns: 1fr;
      }

      .side-panel {
        position: static;
        grid-template-columns: repeat(2, minmax(0, 1fr));
      }

      .desktop-nav,
      .nav-wrap > .hidden.lg\:flex {
        display: none !important;
      }

      .mobile-toggle {
        display: inline-flex;
      }

      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }

      .footer-brand {
        grid-column: 1 / -1;
      }
    }

    @media (max-width: 768px) {
      .site-container {
        width: min(100% - 28px, 1180px);
      }

      .nav-wrap {
        height: 66px;
      }

      .logo-mark {
        width: 36px;
        height: 36px;
        border-radius: 13px;
      }

      .logo-title {
        max-width: 210px;
        overflow: hidden;
        text-overflow: ellipsis;
        font-size: 14px;
      }

      .logo-sub {
        display: none;
      }

      .article-hero {
        padding: 42px 0 48px;
      }

      .article-desc {
        font-size: 16px;
      }

      .article-meta {
        gap: 8px;
      }

      .meta-pill {
        width: fit-content;
      }

      .main-section {
        padding: 42px 0 70px;
      }

      .article-body {
        padding: 22px;
      }

      .prose-content {
        font-size: 16px;
        line-height: 1.82;
      }

      .side-panel {
        grid-template-columns: 1fr;
      }

      .return-panel,
      .cta-inner {
        align-items: stretch;
        flex-direction: column;
      }

      .return-panel .btn,
      .cta-inner .btn {
        width: 100%;
      }

      .footer-grid {
        grid-template-columns: 1fr;
      }

      .footer-bottom {
        align-items: flex-start;
        flex-direction: column;
      }
    }

    @media (max-width: 520px) {
      .breadcrumb {
        font-size: 13px;
      }

      .article-title {
        letter-spacing: -.035em;
      }

      .badge {
        max-width: 100%;
        line-height: 1.35;
      }

      .article-card,
      .cta-strip {
        border-radius: 22px;
      }

      .empty-state {
        padding: 26px 18px;
      }

      .btn {
        width: 100%;
      }
    }