/* roulang page: index */
:root {
      --bs-primary: #1A5F7A;
      --bs-primary-rgb: 26, 95, 122;
      --bs-body-bg: #F8FAFC;
      --bs-body-color: #1E293B;
      --bs-border-radius: 12px;
      --bs-btn-border-radius: 8px;
      --color-accent: #FF6B35;
      --color-accent-dark: #E55A2B;
      --color-success: #0D9488;
      --color-text-weak: #64748B;
      --color-border: #E2E8F0;
      --color-bg-dark: #0F172A;
      --font-sans: 'Inter', 'SF Pro Text', -apple-system, 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --shadow-card: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 8px 24px rgba(0,0,0,0.08);
      --transition-base: all 0.25s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bs-body-bg);
      color: var(--bs-body-color);
      line-height: 1.75;
      margin: 0;
      overflow-x: hidden;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-base);
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    h1, h2, h3, h4 {
      font-weight: 700;
      letter-spacing: -0.02em;
    }

    h1 {
      font-size: 2.75rem;
      line-height: 1.2;
    }

    h2 {
      font-size: 2rem;
    }

    h3 {
      font-size: 1.5rem;
      font-weight: 600;
    }

    .text-weak {
      color: var(--color-text-weak);
    }

    .bg-accent {
      background-color: var(--color-accent);
    }

    .text-accent {
      color: var(--color-accent);
    }

    .btn-primary-custom {
      background-color: var(--color-accent);
      border: none;
      color: white;
      padding: 12px 28px;
      border-radius: 8px;
      font-weight: 600;
      transition: var(--transition-base);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 12px rgba(255,107,53,0.2);
      border: 1px solid transparent;
    }

    .btn-primary-custom:hover {
      background-color: var(--color-accent-dark);
      box-shadow: 0 8px 20px rgba(255,107,53,0.35);
      transform: translateY(-1px);
      color: white;
    }

    .btn-outline-custom {
      background: transparent;
      border: 1px solid var(--bs-primary);
      color: var(--bs-primary);
      padding: 10px 24px;
      border-radius: 8px;
      font-weight: 600;
      transition: var(--transition-base);
    }

    .btn-outline-custom:hover {
      background-color: rgba(26,95,122,0.05);
      border-color: var(--bs-primary);
      color: var(--bs-primary);
    }

    /* 左侧导航 App Shell */
    .app-sidebar {
      position: fixed;
      left: 0;
      top: 0;
      width: 240px;
      height: 100vh;
      background: #FFFFFF;
      border-right: 1px solid var(--color-border);
      display: flex;
      flex-direction: column;
      padding: 2rem 1.5rem;
      z-index: 1050;
      box-shadow: 2px 0 8px rgba(0,0,0,0.02);
    }

    .sidebar-logo {
      font-size: 1.75rem;
      font-weight: 700;
      color: var(--bs-primary);
      margin-bottom: 2.5rem;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .sidebar-logo i {
      color: var(--color-accent);
      font-size: 2rem;
    }

    .nav-menu {
      display: flex;
      flex-direction: column;
      gap: 0.5rem;
      list-style: none;
      padding: 0;
      margin: 0;
    }

    .nav-menu li a {
      display: block;
      padding: 0.75rem 1rem;
      border-radius: 8px;
      color: var(--color-text-weak);
      font-weight: 500;
      position: relative;
      border-left: 3px solid transparent;
      transition: var(--transition-base);
    }

    .nav-menu li a:hover,
    .nav-menu li a.active {
      color: var(--bs-primary);
      background-color: rgba(26,95,122,0.04);
      border-left-color: var(--color-accent);
    }

    .main-content {
      margin-left: 240px;
      width: calc(100% - 240px);
    }

    /* 移动端导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: white;
      z-index: 1040;
      padding: 1rem 1.5rem;
      border-bottom: 1px solid var(--color-border);
      align-items: center;
      justify-content: space-between;
    }

    .menu-overlay {
      display: none;
    }

    @media (max-width: 768px) {
      .app-sidebar {
        display: none;
      }
      .mobile-header {
        display: flex;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
        padding-top: 70px;
      }
      .mobile-sidebar {
        position: fixed;
        left: -280px;
        top: 0;
        width: 280px;
        height: 100%;
        background: white;
        z-index: 1060;
        transition: left 0.3s ease;
        padding: 2rem;
        box-shadow: 2px 0 20px rgba(0,0,0,0.1);
      }
      .mobile-sidebar.open {
        left: 0;
      }
      .menu-overlay {
        display: none;
        position: fixed;
        inset: 0;
        background: rgba(0,0,0,0.4);
        z-index: 1055;
      }
      .menu-overlay.show {
        display: block;
      }
      h1 {
        font-size: 2.2rem;
      }
      h2 {
        font-size: 1.8rem;
      }
    }

    /* 区块间距 */
    section {
      padding: 5rem 0;
    }

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

    @media (max-width: 768px) {
      section {
        padding: 3.5rem 0;
      }
      .container-custom {
        padding: 0 1.5rem;
      }
    }

    /* 卡片 */
    .card-custom {
      background: #FFFFFF;
      border-radius: 12px;
      box-shadow: var(--shadow-card);
      transition: var(--transition-base);
      border: none;
      height: 100%;
    }

    .card-custom:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-2px);
    }

    /* 对比表 */
    .compare-table {
      border-radius: 16px;
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }

    .compare-left {
      background: #F1F5F9;
    }

    .compare-right {
      background: #FFFFFF;
      border-left: 4px solid var(--color-success);
    }

    .faq-item {
      border-bottom: 1px solid var(--color-border);
    }

    .accordion-button:not(.collapsed) {
      background: transparent;
      color: var(--bs-primary);
      box-shadow: none;
    }

    .accordion-button:focus {
      border-color: transparent;
      box-shadow: none;
    }

    footer {
      background: var(--color-bg-dark);
      color: #CBD5E1;
    }

    .footer-link {
      color: #94A3B8;
      transition: var(--transition-base);
    }
    .footer-link:hover {
      color: white;
    }

    .hero-image {
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 400px;
      border-radius: 24px;
      position: relative;
      overflow: hidden;
    }

    .hero-image::after {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(26,95,122,0.1) 0%, rgba(0,0,0,0.05) 100%);
    }