/* roulang page: index */
:root {
      --ink: #0B0C10;
      --titanium: #C0C2C5;
      --signal: #00F0B5;
      --white: #FFFFFF;
      --soft-bg: #F5F6F8;
      --border-light: #E5E7EB;
      --text-dark: #2C2C2C;
      --text-muted: #6B7280;
      --radius-sm: 8px;
      --radius-md: 12px;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.03);
      --shadow-hover: 0 12px 32px rgba(0,0,0,0.08);
      --font-serif: 'Noto Serif SC', 'Source Han Serif SC', serif;
      --font-sans: 'Inter', 'SF Pro Text', -apple-system, sans-serif;
      --font-mono: 'JetBrains Mono', 'SF Mono', monospace;
    }
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: var(--font-sans);
      background-color: var(--white);
      color: var(--text-dark);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    img { max-width: 100%; display: block; }
    a { text-decoration: none; color: inherit; }
    .container { max-width: 1280px; margin: 0 auto; padding: 0 24px; }

    /* 导航 */
    .nav {
      position: sticky; top: 0; z-index: 50;
      background: rgba(255,255,255,0.92); backdrop-filter: blur(8px);
      height: 72px; display: flex; align-items: center;
      border-bottom: 1px solid var(--border-light);
    }
    .nav-inner {
      display: flex; justify-content: space-between; align-items: center;
      width: 100%; max-width: 1280px; margin: 0 auto; padding: 0 24px;
    }
    .logo {
      font-family: var(--font-serif); font-weight: 700; font-size: 1.8rem;
      letter-spacing: -0.02em; color: var(--ink);
    }
    .nav-links { display: flex; gap: 2rem; align-items: center; }
    .nav-links a {
      font-size: 0.9rem; font-weight: 500; color: var(--text-dark);
      padding-bottom: 6px; border-bottom: 2px solid transparent;
      transition: border-color 0.2s;
    }
    .nav-links a.active, .nav-links a:hover { border-bottom-color: var(--signal); }
    .hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; background: none; border: none; }
    .hamburger span { width: 24px; height: 2px; background: var(--ink); border-radius: 2px; transition: 0.2s; }

    /* 首屏 Hero */
    #hero {
      background: linear-gradient(180deg, #F8F9FB 0%, #FFFFFF 100%);
      padding: 100px 0 80px;
    }
    .hero-grid { display: flex; align-items: center; gap: 60px; flex-wrap: wrap; }
    .hero-text { flex: 1; }
    .hero-text h1 {
      font-family: var(--font-serif); font-size: 3.2rem; font-weight: 700;
      line-height: 1.2; color: var(--ink); letter-spacing: -0.02em;
    }
    .hero-text .sub {
      font-size: 1.2rem; color: var(--titanium); margin: 1.2rem 0 2rem;
    }
    .live-data {
      font-family: var(--font-mono); font-size: 1.8rem; color: var(--signal);
      margin-bottom: 1.8rem; font-weight: 500;
    }
    .btn-primary {
      background: var(--ink); color: var(--white); padding: 14px 36px;
      border-radius: 40px; font-weight: 600; font-size: 0.95rem; border: none;
      cursor: pointer; transition: all 0.3s; display: inline-block;
    }
    .btn-primary:hover { background: var(--signal); color: var(--ink); }
    .hero-visual {
      flex: 1; background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 380px; border-radius: var(--radius-md);
    }

    /* 数据看板 */
    #dashboard { background: var(--white); padding: 100px 0; }
    .section-title {
      font-family: var(--font-serif); font-size: 2.2rem; font-weight: 700;
      color: var(--ink); text-align: center; margin-bottom: 48px;
    }
    .metric-grid {
      display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
      gap: 24px;
    }
    .metric-card {
      background: var(--white); border: 1px solid var(--border-light);
      border-radius: var(--radius-sm); padding: 32px 20px; text-align: center;
      box-shadow: var(--shadow-card); transition: all 0.3s ease;
    }
    .metric-card:hover { box-shadow: var(--shadow-hover); transform: translateY(-4px); }
    .metric-number {
      font-family: var(--font-mono); font-size: 2.4rem; color: var(--signal);
      font-weight: 600; margin-bottom: 8px;
    }
    .metric-label { font-size: 0.9rem; color: var(--titanium); }

    /* 服务矩阵 */
    #services { background: var(--soft-bg); padding: 100px 0; }
    .services-grid {
      display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px;
    }
    .service-card {
      background: var(--white); border: 1px solid var(--border-light);
      border-radius: var(--radius-sm); padding: 40px 24px;
      box-shadow: var(--shadow-card); transition: all 0.3s;
      display: flex; flex-direction: column;
    }
    .service-card:hover { box-shadow: var(--shadow-hover); transform: translateY(-4px); }
    .service-icon {
      font-size: 2rem; color: var(--signal); margin-bottom: 20px;
    }
    .service-card h3 { font-size: 1.3rem; font-weight: 600; margin-bottom: 10px; }
    .service-desc { color: var(--text-muted); margin-bottom: 16px; line-height: 1.7; }
    .service-meta { font-family: var(--font-mono); font-size: 0.9rem; color: var(--signal); margin-top: auto; }

    /* 效能对比 */
    #comparison { background: var(--white); padding: 100px 0; }
    .compare-wrapper {
      display: flex; gap: 24px; align-items: center;
    }
    .compare-col {
      flex: 1; background: var(--soft-bg); border-radius: var(--radius-md);
      padding: 32px; border: 1px solid var(--border-light);
    }
    .compare-col.highlight { background: var(--ink); color: var(--white); border-color: var(--ink); }
    .compare-col h3 { font-size: 1.4rem; margin-bottom: 20px; }
    .compare-stat { display: flex; justify-content: space-between; margin-bottom: 12px; }
    .old-val { color: var(--text-muted); }
    .new-val { color: var(--signal); font-weight: 700; }

    /* 信任案例 */
    #trust { background: var(--soft-bg); padding: 100px 0; }
    .trust-scroll {
      display: flex; gap: 24px; overflow-x: auto; padding-bottom: 20px;
    }
    .trust-card {
      min-width: 260px; background: var(--white); border-radius: var(--radius-sm);
      padding: 24px; border: 1px solid var(--border-light); box-shadow: var(--shadow-card);
    }
    .trust-percent { font-family: var(--font-mono); font-size: 2rem; color: var(--signal); font-weight: 600; }
    .trust-desc { font-size: 0.9rem; color: var(--text-dark); margin-top: 8px; }

    /* FAQ */
    #faq { background: var(--white); padding: 100px 0; }
    .faq-grid { display: flex; gap: 40px; }
    .faq-left { flex: 1; display: flex; flex-direction: column; gap: 12px; }
    .faq-q {
      font-weight: 600; font-size: 1rem; padding: 12px 16px;
      background: var(--white); border: 1px solid var(--border-light);
      border-radius: var(--radius-sm); cursor: pointer; transition: 0.2s;
    }
    .faq-q.active { border-left: 4px solid var(--signal); background: #f9fafb; }
    .faq-right { flex: 1.2; }
    .faq-answer {
      font-size: 0.95rem; color: var(--text-muted); line-height: 1.8;
      padding: 16px; display: none;
    }
    .faq-answer.active { display: block; }

    /* CTA */
    #cta {
      background: var(--ink); color: var(--white); padding: 100px 0;
    }
    .cta-inner { display: flex; gap: 60px; align-items: center; flex-wrap: wrap; }
    .cta-text { flex: 1; }
    .cta-text h2 {
      font-family: var(--font-serif); font-size: 2.5rem; font-weight: 700;
    }
    .cta-form { flex: 1; display: flex; flex-direction: column; gap: 20px; }
    .cta-form input, .cta-form textarea {
      background: transparent; border: none; border-bottom: 1px solid var(--titanium);
      padding: 12px 0; color: white; font-size: 1rem; outline: none;
    }
    .cta-form input::placeholder, .cta-form textarea::placeholder { color: var(--titanium); }
    .btn-signal {
      background: var(--signal); color: var(--ink); padding: 14px 32px;
      border-radius: 40px; font-weight: 700; border: none; cursor: pointer; transition: all 0.3s;
    }
    .btn-signal:hover { background: var(--white); color: var(--ink); }

    /* 页脚 */
    #footer {
      background: var(--ink); color: var(--titanium); padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid; grid-template-columns: repeat(4, 1fr); gap: 40px;
    }
    .footer-links a { display: block; margin-bottom: 10px; transition: color 0.2s; }
    .footer-links a:hover { color: var(--signal); }
    .copyright {
      border-top: 1px solid #333; margin-top: 40px; padding-top: 20px; text-align: center;
      font-size: 0.85rem;
    }

    @media (max-width: 1024px) {
      .services-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero-grid { flex-direction: column; }
      .services-grid { grid-template-columns: 1fr; }
      .compare-wrapper { flex-direction: column; }
      .faq-grid { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 520px) {
      .metric-grid { grid-template-columns: 1fr 1fr; }
    }