/* roulang page: index */
:root {
      --primary: #0B0C2A;
      --primary-deep: #06071A;
      --gradient-start: #0B0C2A;
      --gradient-mid: #1B2D5C;
      --gradient-end: #2F4A8A;
      --accent: #F0A500;
      --accent-dark: #D99400;
      --bg-page: #F7F8FC;
      --white: #FFFFFF;
      --text-primary: #1A1A2E;
      --text-secondary: #5A5A72;
      --text-light: #9090A0;
      --border: #E2E4ED;
      --success: #10B981;
      --danger: #EF4444;
      --radius-lg: 20px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --shadow-card: 0 4px 20px rgba(11, 12, 42, 0.06);
      --shadow-hover: 0 12px 32px rgba(11, 12, 42, 0.12);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      --font-mono: "Inter", "Segoe UI", sans-serif;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-page);
      color: var(--text-secondary);
      line-height: 1.7;
      font-size: 16px;
      -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;
    }
    h1, h2, h3, h4 {
      color: var(--text-primary);
    }
    h1 {
      font-size: 36px;
      line-height: 1.2;
      font-weight: 700;
    }
    h2 {
      font-size: 28px;
      line-height: 1.3;
      font-weight: 700;
      margin-bottom: 12px;
      display: inline-block;
      position: relative;
    }
    h2::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -8px;
      width: 40px;
      height: 3px;
      background-color: var(--accent);
      border-radius: 4px;
    }
    h3 {
      font-size: 20px;
      font-weight: 600;
      line-height: 1.4;
    }
    .text-monospace {
      font-family: var(--font-mono);
    }
    /* 导航 */
    .main-header {
      position: fixed;
      top: 0;
      width: 100%;
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(8px);
      z-index: 99;
      height: 64px;
      border-bottom: 1px solid rgba(227, 228, 237, 0.5);
      transition: box-shadow 0.2s ease;
    }
    .main-header.scrolled {
      box-shadow: 0 4px 20px rgba(0,0,0,0.04);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 64px;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo i {
      color: var(--accent);
      font-size: 26px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 28px;
      list-style: none;
    }
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-secondary);
      transition: color 0.2s;
    }
    .nav-links a:hover, .nav-links a.active {
      color: var(--accent);
    }
    .btn-primary {
      background: var(--accent);
      color: var(--primary);
      font-weight: 600;
      padding: 10px 22px;
      border-radius: 50px;
      border: none;
      cursor: pointer;
      transition: background 0.2s, box-shadow 0.2s;
      font-size: 15px;
      box-shadow: 0 4px 12px rgba(240,165,0,0.25);
      display: inline-block;
      letter-spacing: 0.3px;
    }
    .btn-primary:hover {
      background: var(--accent-dark);
      box-shadow: 0 0 18px rgba(240,165,0,0.5);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--accent);
      color: var(--accent);
      font-weight: 600;
      padding: 10px 22px;
      border-radius: 50px;
      cursor: pointer;
      transition: all 0.25s;
      font-size: 15px;
      display: inline-block;
    }
    .btn-outline:hover {
      background: var(--accent);
      color: var(--primary);
    }
    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--text-primary);
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .mobile-toggle {
        display: block;
      }
      .header-inner .btn-primary {
        display: none;
      }
      .mobile-menu {
        position: fixed;
        top: 64px;
        left: 0;
        width: 100%;
        background: rgba(11,12,42,0.95);
        backdrop-filter: blur(12px);
        flex-direction: column;
        padding: 40px 24px;
        gap: 28px;
        display: none;
      }
      .mobile-menu.open {
        display: flex;
      }
      .mobile-menu a {
        color: white;
        font-size: 20px;
      }
      .mobile-menu .btn-primary {
        display: inline-block;
        width: fit-content;
      }
    }
    section {
      padding: 80px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 48px 0;
      }
      h1 {
        font-size: 30px;
      }
      h2 {
        font-size: 24px;
      }
    }
    /* hero */
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
      min-height: 85vh;
      padding-top: 64px;
    }
    .hero-left {
      flex: 1;
    }
    .hero-right {
      flex: 1;
      background: linear-gradient(135deg, var(--gradient-start), var(--gradient-mid));
      border-radius: 28px;
      height: 420px;
      display: flex;
      align-items: center;
      justify-content: center;
      overflow: hidden;
      position: relative;
    }
    .hero-right img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      opacity: 0.9;
    }
    .hero-tagline {
      font-size: 16px;
      color: var(--accent);
      font-weight: 600;
      letter-spacing: 1px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      margin-top: 28px;
      flex-wrap: wrap;
    }
    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
        gap: 40px;
      }
      .hero-right {
        height: 300px;
      }
    }

    /* 卡片通用 */
    .card {
      background: var(--white);
      border-radius: 20px;
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .grid-features {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 36px;
    }
    .feature-card {
      padding: 28px 20px;
      text-align: center;
      border-top: 4px solid transparent;
    }
    .feature-card:hover {
      border-top-color: var(--accent);
    }
    .feature-icon {
      font-size: 40px;
      color: var(--accent);
      margin-bottom: 16px;
    }
    .data-badge {
      background: rgba(240,165,0,0.12);
      color: #b2800a;
      font-weight: 800;
      font-size: 22px;
      padding: 6px 12px;
      border-radius: 30px;
      margin-top: 14px;
      display: inline-block;
    }

    /* 产品交替布局 */
    .product-row {
      display: flex;
      align-items: center;
      gap: 40px;
      margin: 48px 0;
      background: var(--white);
      border-radius: 20px;
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: 0.2s;
    }
    .product-row.reverse {
      flex-direction: row-reverse;
    }
    .product-img {
      width: 42%;
      background: #eef0f8;
      min-height: 260px;
    }
    .product-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .product-info {
      padding: 28px;
      flex: 1;
    }
    .tag {
      background: #edf0f8;
      color: var(--text-secondary);
      font-size: 12px;
      padding: 4px 12px;
      border-radius: 20px;
      font-weight: 500;
      margin-right: 8px;
    }
    .product-tags {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      margin: 16px 0;
    }

    .showcase-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 20px;
      margin-top: 32px;
    }
    .showcase-card {
      position: relative;
      border-radius: 20px;
      overflow: hidden;
      background: var(--primary);
      transition: 0.2s;
    }
    .showcase-card img {
      width: 100%;
      height: 220px;
      object-fit: cover;
      opacity: 0.85;
    }
    .showcase-overlay {
      position: absolute;
      bottom: 0;
      background: linear-gradient(transparent, rgba(0,0,0,0.7));
      width: 100%;
      padding: 20px;
      color: white;
    }
    @media (max-width:768px){
      .grid-features, .showcase-grid {
        grid-template-columns: 1fr;
      }
      .product-row, .product-row.reverse {
        flex-direction: column;
      }
      .product-img {
        width: 100%;
        height: 220px;
      }
    }

    .compare-table {
      display: flex;
      gap: 24px;
      margin-top: 28px;
      overflow-x: auto;
      padding-bottom: 12px;
    }
    .compare-col {
      flex: 1;
      min-width: 220px;
      background: white;
      border-radius: 20px;
      padding: 28px 18px;
      border: 2px solid var(--border);
      transition: 0.2s;
    }
    .compare-col.recommend {
      border-color: var(--accent);
      border-width: 2px;
      transform: scale(1.03);
      background: #fffef5;
    }
    .badge-recommend {
      background: var(--accent);
      color: #0B0C2A;
      font-weight: 700;
      padding: 4px 14px;
      border-radius: 20px;
      font-size: 13px;
    }
    .faq-item {
      background: #F7F8FC;
      border-radius: 12px;
      margin-bottom: 12px;
      padding: 16px 20px;
      cursor: pointer;
      transition: 0.15s;
    }
    .faq-item.active {
      background: white;
      border-left: 4px solid var(--accent);
    }
    .faq-answer {
      display: none;
      margin-top: 12px;
      color: var(--text-secondary);
      font-weight: 400;
    }
    .faq-item.active .faq-answer {
      display: block;
    }

    .cta-banner {
      background: linear-gradient(135deg, #0B0C2A, #2F4A8A);
      text-align: center;
      color: white;
      border-radius: 28px;
      padding: 64px 28px;
      margin: 40px 0;
    }
    footer {
      background: var(--primary);
      color: #b0b2c5;
      padding: 60px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    .footer-bottom {
      border-top: 1px solid #252740;
      margin-top: 36px;
      padding-top: 24px;
      text-align: center;
      font-size: 14px;
      color: #7e7f92;
      background: var(--primary-deep);
    }
    @media(max-width:768px){
      .footer-grid{grid-template-columns:1fr 1fr;}
    }