/* roulang page: index */
:root {
      --primary: #1A5F7A;
      --primary-dark: #154E64;
      --accent: #F39C12;
      --bg: #F8FAFC;
      --card-bg: #FFFFFF;
      --text-main: #1E293B;
      --text-secondary: #64748B;
      --border: #E2E8F0;
      --success: #10B981;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 8px;
      --shadow-card: 0 1px 3px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.06);
      --shadow-card-hover: 0 10px 25px rgba(0,0,0,0.08), 0 4px 10px rgba(0,0,0,0.04);
      --font-zh: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, sans-serif;
      --font-en: "Inter", "Segoe UI", system-ui, sans-serif;
      --sidebar-width: 260px;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-zh);
      background: var(--bg);
      color: var(--text-main);
      margin: 0;
      line-height: 1.7;
      font-size: 16px;
      display: flex;
      min-height: 100vh;
    }

    h1, h2, h3, h4 {
      font-weight: 700;
    }

    a {
      color: var(--primary);
      text-decoration: none;
      transition: color 0.2s;
    }
    a:hover {
      color: var(--accent);
      text-decoration: none;
    }

    .custom-btn {
      border-radius: var(--radius-btn);
      padding: 0.75rem 2rem;
      font-weight: 500;
      transition: all 0.2s ease;
      display: inline-block;
      text-align: center;
    }
    .btn-primary-custom {
      background: var(--primary);
      border: none;
      color: white;
      box-shadow: none;
    }
    .btn-primary-custom:hover {
      background: var(--primary-dark);
      color: white;
      box-shadow: 0 4px 12px rgba(26,95,122,0.3);
    }
    .btn-outline-custom {
      border: 2px solid var(--primary);
      background: transparent;
      color: var(--primary);
    }
    .btn-outline-custom:hover {
      background: rgba(26,95,122,0.08);
      color: var(--primary-dark);
      border-color: var(--primary-dark);
    }
    .btn-accent {
      background: var(--accent);
      border: none;
      color: #1E293B;
      font-weight: 600;
    }
    .btn-accent:hover {
      background: #e08e0b;
      color: #1E293B;
    }

    /* 左侧导航栏 App Shell */
    .app-sidebar {
      width: var(--sidebar-width);
      height: 100vh;
      position: fixed;
      top: 0;
      left: 0;
      background: rgba(26, 95, 122, 0.04);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border-right: 1px solid var(--border);
      display: flex;
      flex-direction: column;
      justify-content: flex-start;
      padding: 2rem 1rem;
      z-index: 1030;
    }

    .sidebar-logo {
      display: flex;
      flex-direction: column;
      align-items: center;
      margin-bottom: 2.5rem;
      font-weight: 700;
      font-size: 1.6rem;
      color: var(--primary);
    }
    .sidebar-logo i {
      font-size: 2.4rem;
      color: var(--accent);
      margin-bottom: 0.25rem;
    }

    .nav-menu {
      display: flex;
      flex-direction: column;
      gap: 0.5rem;
      flex: 1;
    }
    .nav-item-custom {
      display: flex;
      align-items: center;
      gap: 0.75rem;
      padding: 0.7rem 1rem;
      border-radius: 8px;
      color: var(--text-secondary);
      font-size: 0.95rem;
      font-weight: 500;
      position: relative;
      transition: all 0.2s;
    }
    .nav-item-custom i {
      width: 20px;
      font-size: 1.2rem;
      text-align: center;
    }
    .nav-item-custom:hover {
      color: var(--primary);
      background: rgba(26,95,122,0.05);
    }
    .nav-item-custom.active {
      color: var(--primary);
      font-weight: 600;
      background: rgba(26,95,122,0.08);
    }
    .nav-item-custom.active::before {
      content: '';
      position: absolute;
      left: 0;
      top: 8px;
      bottom: 8px;
      width: 4px;
      background: linear-gradient(to bottom, var(--accent), var(--primary));
      border-radius: 0 4px 4px 0;
    }

    /* 主内容区 */
    .main-content {
      margin-left: var(--sidebar-width);
      flex: 1;
      width: calc(100% - var(--sidebar-width));
      overflow-x: hidden;
    }

    section {
      padding: 100px 0;
    }

    .section-title {
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 1rem;
      color: var(--text-main);
    }
    .section-desc {
      color: var(--text-secondary);
      font-size: 1.1rem;
      max-width: 700px;
      margin-bottom: 3rem;
    }

    .container-custom {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 2rem;
    }

    /* Hero */
    .hero-section {
      background: linear-gradient(135deg, #F8FAFC 0%, #ffffff 100%);
    }
    .hero-title {
      font-size: 3.2rem;
      font-weight: 700;
      line-height: 1.2;
      color: var(--text-main);
    }
    .hero-sub {
      font-size: 1.25rem;
      color: var(--text-secondary);
      margin: 1.5rem 0 2rem;
    }

    /* 卡片通用 */
    .feature-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 2rem;
      box-shadow: var(--shadow-card);
      transition: all 0.25s;
    }
    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-card-hover);
    }
    .feature-icon {
      font-size: 2.2rem;
      color: var(--primary);
      margin-bottom: 1rem;
    }

    .scenario-img {
      border-radius: 16px;
      box-shadow: 0 8px 20px rgba(0,0,0,0.06);
      width: 100%;
      height: auto;
    }

    .pricing-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 2rem;
      box-shadow: var(--shadow-card);
      transition: 0.2s;
      position: relative;
    }
    .pricing-card.recommended {
      border-top: 6px solid var(--accent);
      transform: scale(1.03);
      box-shadow: var(--shadow-card-hover);
    }
    .price-number {
      font-family: var(--font-en);
      font-size: 3rem;
      font-weight: 700;
      color: var(--accent);
    }

    .accordion-button:not(.collapsed) {
      background-color: #F1F5F9;
      color: var(--primary);
      border-bottom: 3px solid var(--primary);
    }
    .accordion-button:focus {
      box-shadow: none;
    }

    .footer-dark {
      background: #1E293B;
      color: #CBD5E1;
    }
    .footer-dark a {
      color: #CBD5E1;
    }
    .footer-dark a:hover {
      color: var(--accent);
    }

    /* 移动端 */
    @media (max-width: 991.98px) {
      .app-sidebar {
        display: none;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
      }
      .mobile-header {
        display: flex;
        align-items: center;
        justify-content: space-between;
        padding: 0.8rem 1.5rem;
        background: rgba(248,250,252,0.9);
        backdrop-filter: blur(12px);
        position: sticky;
        top: 0;
        z-index: 1040;
        border-bottom: 1px solid var(--border);
      }
      section {
        padding: 60px 0;
      }
      .hero-title {
        font-size: 2.4rem;
      }
    }
    @media (min-width: 992px) {
      .mobile-header {
        display: none;
      }
    }