/* roulang page: index */
:root {
      --primary-deep: #1A2B4C;
      --accent-orange: #E85D04;
      --bg-light: #F4F6F9;
      --card-white: #FFFFFF;
      --tech-cyan: #00B4D8;
      --text-dark: #0F172A;
      --text-muted: #64748B;
      --success: #10B981;
      --danger: #EF4444;
      --border-radius-card: 12px;
      --border-radius-btn: 8px;
      --shadow-sm: 0 4px 20px rgba(0, 0, 0, 0.04);
      --shadow-hover: 0 8px 30px rgba(0, 0, 0, 0.08);
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-data: 'Inter', 'SF Pro Display', system-ui;
      --transition-base: 0.25s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.7;
      margin: 0;
      padding: 0;
      overflow-x: hidden;
    }

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

    a {
      text-decoration: none;
      transition: color 0.2s;
    }

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

    .container-custom {
      max-width: 1280px;
      margin: 0 auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }

    /* 导航 */
    .navbar-custom {
      background-color: rgba(255, 255, 255, 0.98);
      backdrop-filter: blur(8px);
      border-bottom: 1px solid rgba(0,0,0,0.02);
      padding: 0.75rem 0;
      transition: all 0.3s;
      position: sticky;
      top: 0;
      z-index: 1020;
      box-shadow: 0 4px 12px rgba(0,0,0,0.02);
    }

    .navbar-brand {
      font-weight: 800;
      font-size: 1.8rem;
      color: var(--primary-deep) !important;
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .navbar-brand i {
      color: var(--accent-orange);
      font-size: 2rem;
    }

    .nav-link {
      color: var(--text-dark) !important;
      font-weight: 500;
      margin: 0 0.5rem;
      padding: 0.5rem 1rem !important;
      border-radius: 20px;
      transition: all 0.2s;
    }

    .nav-link:hover, .nav-link.active {
      color: var(--accent-orange) !important;
      background-color: rgba(232, 93, 4, 0.04);
    }

    .search-icon {
      color: var(--text-muted);
      font-size: 1.2rem;
      cursor: pointer;
      transition: 0.2s;
      margin-left: 0.8rem;
    }

    .search-icon:hover {
      color: var(--accent-orange);
    }

    .hot-tag {
      background: rgba(0,180,216,0.1);
      color: var(--tech-cyan);
      padding: 0.25rem 0.8rem;
      border-radius: 20px;
      font-size: 0.8rem;
      font-weight: 600;
      margin-left: 0.5rem;
    }

    /* Hero */
    .hero-section {
      background: linear-gradient(135deg, #1A2B4C 0%, #0F1D33 100%);
      position: relative;
      overflow: hidden;
      padding: 5rem 0 6rem;
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 3rem;
    }

    .hero-left {
      flex: 1 1 55%;
    }

    .hero-right {
      flex: 1 1 45%;
      position: relative;
    }

    .hero-title {
      font-size: 3.4rem;
      font-weight: 800;
      color: white;
      line-height: 1.2;
      margin-bottom: 1.5rem;
    }

    .hero-sub {
      font-size: 1.2rem;
      color: #CBD5E1;
      margin-bottom: 2.2rem;
      max-width: 90%;
    }

    .btn-primary-custom {
      background: var(--accent-orange);
      border: none;
      color: white;
      font-weight: 600;
      padding: 0.75rem 2rem;
      border-radius: var(--border-radius-btn);
      transition: all 0.2s;
      box-shadow: 0 4px 12px rgba(232,93,4,0.3);
    }

    .btn-primary-custom:hover {
      background: #D14D00;
      box-shadow: 0 6px 18px rgba(209,77,0,0.4);
      color: white;
    }

    .btn-outline-custom {
      border: 2px solid white;
      color: white;
      font-weight: 600;
      padding: 0.75rem 2rem;
      border-radius: var(--border-radius-btn);
      background: transparent;
      transition: 0.2s;
      margin-left: 1rem;
    }

    .btn-outline-custom:hover {
      background: rgba(255,255,255,0.1);
      border-color: white;
      color: white;
    }

    .hero-img {
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      border-radius: 24px;
      height: 380px;
      width: 100%;
      box-shadow: 0 20px 40px rgba(0,0,0,0.3);
      position: relative;
      overflow: hidden;
    }

    .section-title {
      font-size: 2.4rem;
      font-weight: 800;
      color: var(--primary-deep);
      margin-bottom: 1rem;
      position: relative;
    }

    .section-sub {
      color: var(--text-muted);
      font-size: 1.1rem;
      margin-bottom: 3rem;
    }

    .card-custom {
      background: var(--card-white);
      border: none;
      border-radius: var(--border-radius-card);
      box-shadow: var(--shadow-sm);
      transition: all var(--transition-base);
      height: 100%;
      padding: 2rem 1.5rem;
    }

    .card-custom:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .icon-circle {
      width: 56px;
      height: 56px;
      background: rgba(232,93,4,0.08);
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 16px;
      color: var(--accent-orange);
      font-size: 1.8rem;
      margin-bottom: 1.5rem;
    }

    .pricing-card {
      border-radius: var(--border-radius-card);
      padding: 2rem;
      background: white;
      box-shadow: var(--shadow-sm);
      transition: 0.2s;
      border: 1px solid rgba(0,0,0,0.02);
    }

    .pricing-card.recommended {
      border: 2px solid var(--accent-orange);
      transform: scale(1.02);
    }

    .faq-item {
      background: white;
      border-radius: 8px;
      margin-bottom: 12px;
      box-shadow: 0 2px 8px rgba(0,0,0,0.02);
    }

    .faq-button {
      font-weight: 600;
      color: var(--text-dark);
      background: transparent;
      box-shadow: none;
      border: none;
      width: 100%;
      text-align: left;
      padding: 1.2rem 1.5rem;
    }

    .faq-button:not(.collapsed) {
      color: var(--accent-orange);
      border-left: 4px solid var(--accent-orange);
    }

    .cta-banner {
      background: var(--primary-deep);
      border-radius: 24px;
      padding: 3.5rem 2rem;
      text-align: center;
      color: white;
    }

    footer {
      background: #0F172A;
      color: #CBD5E1;
      padding: 4rem 0 2rem;
    }

    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
        text-align: center;
      }
      .hero-title {
        font-size: 2.3rem;
      }
      .btn-outline-custom {
        margin-left: 0;
        margin-top: 1rem;
      }
      .navbar-collapse {
        background: white;
        padding: 1rem;
        border-radius: 16px;
        margin-top: 0.5rem;
      }
    }