/* roulang page: index */
:root {
      --primary-deep: #0B1A2F;
      --accent-red: #E94E3C;
      --accent-green: #1EC9A4;
      --bg-light: #F7F8FA;
      --card-white: #FFFFFF;
      --border-light: #E4E7EC;
      --text-dark: #0B1A2F;
      --text-body: #4A5568;
      --text-light-bg: #CBD5E1;
      --text-muted: #8899AA;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.04), 0 0 0 1px rgba(0,0,0,0.02);
      --shadow-hover: 0 12px 28px rgba(0,0,0,0.08), 0 0 0 1px rgba(0,0,0,0.02);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-body);
      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;
      transition: color 0.2s, background 0.2s;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航栏 SaaS 命令栏风格 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: rgba(255,255,255,0.94);
      backdrop-filter: blur(10px);
      -webkit-backdrop-filter: blur(10px);
      box-shadow: 0 1px 4px rgba(0,0,0,0.04);
      z-index: 100;
      display: flex;
      align-items: center;
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      font-size: 20px;
      font-weight: 700;
      color: var(--primary-deep);
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo i {
      font-size: 24px;
      color: var(--accent-red);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 28px;
      list-style: none;
      margin: 0;
    }
    .nav-links a {
      font-size: 14px;
      font-weight: 500;
      color: var(--text-body);
      padding: 4px 0;
      position: relative;
      border-bottom: 2px solid transparent;
      transition: color 0.2s, border-color 0.2s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary-deep);
      border-bottom-color: var(--accent-red);
    }
    .search-cta-group {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .search-box {
      background: #F1F3F5;
      border-radius: 20px;
      padding: 6px 16px;
      display: flex;
      align-items: center;
      gap: 8px;
      color: var(--text-muted);
      font-size: 14px;
    }
    .search-box i {
      font-size: 13px;
    }
    .search-box input {
      border: none;
      background: transparent;
      outline: none;
      font-size: 14px;
      width: 100px;
      color: var(--text-body);
    }
    .btn-primary {
      background: var(--accent-red);
      color: white;
      font-weight: 600;
      font-size: 14px;
      padding: 0 20px;
      height: 40px;
      border-radius: var(--radius-btn);
      display: flex;
      align-items: center;
      justify-content: center;
      transition: background 0.2s, box-shadow 0.2s;
      border: none;
      cursor: pointer;
      white-space: nowrap;
    }
    .btn-primary:hover {
      background: #C83A2A;
      box-shadow: inset 0 2px 4px rgba(0,0,0,0.1);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary-deep);
      color: var(--primary-deep);
      font-weight: 600;
      font-size: 15px;
      padding: 0 24px;
      height: 48px;
      border-radius: var(--radius-btn);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: all 0.2s;
      cursor: pointer;
    }
    .btn-outline:hover {
      background: rgba(11,26,47,0.05);
      border-color: var(--accent-red);
      color: var(--accent-red);
    }
    .btn-large {
      height: 48px;
      padding: 0 32px;
      font-size: 15px;
      min-width: 160px;
    }
    .text-link {
      color: var(--accent-green);
      font-weight: 500;
      font-size: 15px;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      transition: color 0.2s;
    }
    .text-link:hover {
      text-decoration: underline;
      color: #17a88b;
    }
    /* 移动端汉堡菜单 */
    .hamburger {
      display: none;
      font-size: 22px;
      color: var(--primary-deep);
      cursor: pointer;
    }
    @media (max-width: 1024px) {
      .nav-links, .search-cta-group .search-box {
        display: none;
      }
      .hamburger {
        display: block;
      }
      .mobile-menu {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        width: 100%;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(12px);
        padding: 20px 24px;
        flex-direction: column;
        gap: 16px;
        box-shadow: 0 8px 20px rgba(0,0,0,0.05);
      }
      .mobile-menu.active {
        display: flex;
      }
      .mobile-menu a {
        font-size: 16px;
        font-weight: 500;
        color: var(--text-dark);
      }
      .mobile-menu .search-box {
        display: flex;
        width: 100%;
        margin-bottom: 8px;
      }
    }
    /* Hero 深色背景 */
    .hero {
      background: var(--primary-deep);
      min-height: 90vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      padding-top: 64px;
    }
    .hero::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: radial-gradient(circle at 20% 30%, rgba(30,201,164,0.08) 0%, transparent 40%);
      pointer-events: none;
    }
    .hero-content {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 40px;
      flex-wrap: wrap;
    }
    .hero-left {
      flex: 1 1 50%;
      color: white;
    }
    .hero-left h1 {
      font-size: 36px;
      font-weight: 700;
      line-height: 1.3;
      letter-spacing: -0.5px;
      color: white;
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 18px;
      color: #CBD5E1;
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-right {
      flex: 1 1 45%;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    .video-mock {
      background: rgba(255,255,255,0.05);
      border-radius: 20px;
      padding: 8px;
      box-shadow: 0 16px 40px rgba(0,0,0,0.4);
      position: relative;
      width: 100%;
      max-width: 480px;
    }
    .video-mock img {
      border-radius: 14px;
      width: 100%;
      object-fit: cover;
    }
    .play-overlay {
      position: absolute;
      top: 50%;
      left: 50%;
      transform: translate(-50%,-50%);
      font-size: 48px;
      color: white;
      background: rgba(233,78,60,0.9);
      width: 72px;
      height: 72px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 8px 20px rgba(0,0,0,0.3);
    }
    @media (max-width: 640px) {
      .hero-left h1 {
        font-size: 28px;
      }
      .hero-content {
        flex-direction: column;
      }
      .hero-right {
        margin-top: 32px;
      }
    }
    /* 通用板块 */
    section {
      padding: 80px 0;
    }
    .section-title {
      font-size: 28px;
      font-weight: 600;
      color: var(--text-dark);
      margin-bottom: 16px;
      text-align: center;
    }
    .section-desc {
      color: var(--text-body);
      max-width: 680px;
      margin: 0 auto 48px;
      text-align: center;
    }
    .card-grid {
      display: flex;
      gap: 24px;
      flex-wrap: wrap;
      justify-content: center;
    }
    .card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 28px 24px;
      box-shadow: var(--shadow-sm);
      transition: all 0.25s;
      flex: 1 1 280px;
      max-width: 360px;
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .icon-circle {
      font-size: 36px;
      color: var(--accent-red);
      margin-bottom: 16px;
    }
    .card h3 {
      font-size: 20px;
      font-weight: 600;
      color: var(--text-dark);
      margin-bottom: 12px;
    }
    /* 图文交错 */
    .feature-row {
      display: flex;
      align-items: center;
      gap: 48px;
      flex-wrap: wrap;
      margin-bottom: 64px;
    }
    .feature-row.reverse {
      flex-direction: row-reverse;
    }
    .feature-text {
      flex: 1 1 45%;
    }
    .feature-img {
      flex: 1 1 45%;
      background: #f0f2f5;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .feature-img img {
      width: 100%;
      height: auto;
    }
    /* 场景卡片 */
    .scenario-card {
      text-align: left;
    }
    .tag-link {
      color: var(--accent-green);
      font-weight: 500;
      margin-top: 12px;
      display: inline-block;
    }
    /* 案例网格 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(260px,1fr));
      gap: 24px;
    }
    .case-item {
      background: white;
      border-radius: var(--radius-card);
      padding: 24px;
      box-shadow: var(--shadow-sm);
    }
    .stat-number {
      font-size: 32px;
      font-weight: 700;
      color: var(--accent-green);
    }
    /* FAQ */
    .accordion-faq {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 16px 0;
    }
    .faq-question {
      font-size: 18px;
      font-weight: 600;
      color: var(--text-dark);
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #F7F8FA;
      border-radius: 8px;
      margin-top: 8px;
      padding: 0 16px;
    }
    .faq-answer.open {
      max-height: 200px;
      padding: 16px;
    }
    /* CTA 横幅 */
    .cta-banner {
      background: var(--primary-deep);
      padding: 80px 0;
      text-align: center;
      color: white;
    }
    .cta-banner h2 {
      color: white;
      font-size: 28px;
      margin-bottom: 16px;
    }
    /* 页脚 */
    .site-footer {
      background: var(--primary-deep);
      color: var(--text-muted);
      padding: 48px 0 24px;
    }
    .footer-grid {
      display: flex;
      flex-wrap: wrap;
      gap: 32px;
      justify-content: space-between;
    }
    .footer-col p {
      font-size: 14px;
      margin-top: 8px;
    }
    @media (max-width: 640px) {
      .btn-large {
        width: 100%;
      }
    }