/* roulang page: index */
/* ----- 设计变量与全局 reset ----- */
    :root {
      --primary: #1A5FDC;
      --primary-deep: #0F3D9E;
      --accent: #FF6B35;
      --bg-page: #F8FAFD;
      --bg-dark: #0B1E3C;
      --text-main: #1A1A2E;
      --text-secondary: #5A6070;
      --text-weak: #8C95A6;
      --success: #00C48C;
      --danger: #E53E3E;
      --white: #FFFFFF;
      --border-light: #E8EDF5;
      --shadow-sm: 0 2px 12px rgba(26,95,220,0.06);
      --shadow-md: 0 8px 28px rgba(26,95,220,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
      --font-mono: "DIN Alternate", "Roboto Mono", "Courier New", monospace;
      --max-width: 1200px;
      --nav-height: 64px;
      --transition: 0.2s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-page);
      color: var(--text-main);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }
    /* 容器与栅格 */
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
    }
    @media (max-width: 768px) {
      .container {
        padding: 0 16px;
      }
    }
    /* 导航 (固定白底) */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: var(--white);
      box-shadow: 0 2px 8px rgba(0,0,0,0.04);
      z-index: 1000;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: var(--max-width);
      padding: 0 20px;
    }
    .logo {
      font-size: 1.6rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.5px;
      white-space: nowrap;
    }
    .logo span {
      color: var(--text-main);
      font-weight: 400;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 2rem;
    }
    .nav-link {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-secondary);
      padding: 0.25rem 0;
      border-bottom: 2px solid transparent;
      transition: color var(--transition), border-color var(--transition);
    }
    .nav-link:hover, .nav-link.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }
    .nav-cta {
      background: var(--primary);
      color: white;
      padding: 0.6rem 1.5rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: background var(--transition);
      white-space: nowrap;
    }
    .nav-cta:hover {
      background: var(--primary-deep);
    }
    .hamburger {
      display: none;
      font-size: 1.6rem;
      color: var(--text-main);
    }
    /* 移动端导航抽屉 */
    @media (max-width: 768px) {
      .nav-menu {
        position: fixed;
        top: var(--nav-height);
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        align-items: flex-start;
        padding: 2rem 1.5rem;
        gap: 1.8rem;
        box-shadow: 0 12px 20px rgba(0,0,0,0.08);
        transform: translateY(-120%);
        opacity: 0;
        transition: transform 0.3s ease, opacity 0.2s ease;
        pointer-events: none;
      }
      .nav-menu.open {
        transform: translateY(0);
        opacity: 1;
        pointer-events: auto;
      }
      .hamburger {
        display: block;
      }
      .nav-cta.desktop-only {
        display: none;
      }
      .nav-cta.mobile-cta {
        display: block;
        width: 100%;
        text-align: center;
      }
    }
    @media (min-width: 769px) {
      .mobile-cta {
        display: none;
      }
    }
    /* 板块通用 */
    section {
      padding: 90px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }
    .section-title {
      font-size: 2rem;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 1rem;
      text-align: center;
    }
    .section-sub {
      color: var(--text-secondary);
      text-align: center;
      max-width: 680px;
      margin: 0 auto 3rem auto;
      font-size: 1.1rem;
    }
    /* Hero */
    .hero {
      padding-top: calc(var(--nav-height) + 50px);
      padding-bottom: 70px;
      background: linear-gradient(135deg, #F0F5FF 0%, #F8FAFD 100%);
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 3rem;
    }
    .hero-left {
      flex: 1;
    }
    .hero-right {
      flex: 1;
      display: flex;
      justify-content: center;
    }
    .hero h1 {
      font-size: 2.8rem;
      font-weight: 700;
      line-height: 1.3;
      color: var(--text-main);
      margin-bottom: 1.2rem;
    }
    .hero-sub {
      font-size: 1.15rem;
      color: var(--text-secondary);
      margin-bottom: 2rem;
    }
    .btn-group {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent);
      color: white;
      padding: 0.85rem 2.2rem;
      border-radius: var(--radius-btn);
      font-weight: 700;
      transition: all 0.2s;
      box-shadow: 0 4px 12px rgba(255,107,53,0.25);
      display: inline-flex;
      align-items: center;
      gap: 0.4rem;
    }
    .btn-primary:hover {
      background: #e85d2a;
      box-shadow: 0 8px 20px rgba(255,107,53,0.35);
    }
    .btn-secondary {
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 0.85rem 2.2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      background: transparent;
      transition: 0.2s;
    }
    .btn-secondary:hover {
      background: rgba(26,95,220,0.05);
    }
    .score-card-mock {
      background: #0B1E3C;
      border-radius: 16px;
      padding: 1.5rem;
      color: white;
      width: 100%;
      max-width: 380px;
      box-shadow: 0 20px 30px rgba(0,0,0,0.3);
      transform: rotate(1deg);
      font-family: var(--font-mono);
    }
    .live-tag {
      background: var(--accent);
      color: white;
      padding: 0.2rem 0.8rem;
      border-radius: 20px;
      font-size: 0.8rem;
      font-weight: 700;
      display: inline-block;
      margin-bottom: 0.8rem;
    }
    .match-row {
      display: flex;
      justify-content: space-between;
      align-items: center;
      margin: 1rem 0;
    }
    .team {
      font-weight: 600;
      font-size: 1.1rem;
    }
    .score {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--success);
    }
    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
      }
      .hero h1 {
        font-size: 2rem;
      }
    }
    /* 卡片通用 */
    .card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 2rem 1.8rem;
      box-shadow: var(--shadow-sm);
      transition: all 0.25s;
      border: 1px solid var(--border-light);
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-md);
    }
    /* 三列网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    @media (max-width: 768px) {
      .grid-3 {
        grid-template-columns: 1fr;
      }
    }
    /* 产品交错区块 */
    .product-row {
      display: flex;
      align-items: center;
      gap: 3rem;
      margin-bottom: 5rem;
    }
    .product-row.reverse {
      flex-direction: row-reverse;
    }
    .product-text {
      flex: 1;
    }
    .product-img {
      flex: 1;
      background: #eef3fc;
      border-radius: 16px;
      overflow: hidden;
      min-height: 240px;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .product-img img {
      object-fit: cover;
      width: 100%;
      height: auto;
    }
    @media (max-width: 768px) {
      .product-row, .product-row.reverse {
        flex-direction: column;
      }
    }
    /* 场景卡片 */
    .scenario-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .scenario-img {
      height: 160px;
      background: #d9e6ff;
    }
    .scenario-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    /* 深色数据条 */
    .dark-strip {
      background: var(--bg-dark);
      color: white;
      padding: 3rem 0;
    }
    .stats-grid {
      display: flex;
      justify-content: space-around;
      text-align: center;
      flex-wrap: wrap;
      gap: 2rem;
    }
    .stat-number {
      font-family: var(--font-mono);
      font-size: 2.5rem;
      font-weight: 700;
      color: var(--accent);
    }
    /* FAQ 手风琴 */
    .faq-item {
      background: white;
      border-radius: var(--radius-card);
      margin-bottom: 1rem;
      padding: 1.2rem 2rem;
      cursor: pointer;
      box-shadow: var(--shadow-sm);
      border-left: 4px solid transparent;
      transition: 0.2s;
    }
    .faq-item.active {
      border-left-color: var(--primary);
    }
    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
      font-size: 0.95rem;
    }
    /* CTA 条 */
    .cta-strip {
      background: rgba(26,95,220,0.04);
      text-align: center;
    }
    /* 页脚 */
    .footer {
      background: #1A1A2E;
      color: #ccc;
      padding: 3rem 0 1.5rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }