/* roulang page: index */
:root {
      --primary: #1A5FCE;
      --primary-hover: #0EA5E9;
      --secondary: #0EA5E9;
      --accent: #F97316;
      --bg: #F8FAFC;
      --card-white: #FFFFFF;
      --text-main: #1E293B;
      --text-secondary: #64748B;
      --border-light: #E2E8F0;
      --success: #10B981;
      --danger: #EF4444;
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --radius-pill: 50px;
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-md: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 30px rgba(0,0,0,0.08);
      --transition: 0.3s ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
      background-color: var(--bg);
      color: var(--text-main);
      line-height: 1.6;
      margin: 0;
      padding: 0;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      display: block;
    }
    /* 覆盖 Bootstrap 默认 */
    .btn {
      border-radius: var(--radius-pill);
      padding: 0.6rem 2rem;
      font-weight: 600;
      transition: var(--transition);
    }
    .btn-primary {
      background-color: var(--primary);
      border-color: var(--primary);
      color: white;
    }
    .btn-primary:hover {
      background-color: var(--primary-hover);
      border-color: var(--primary-hover);
      color: white;
      transform: translateY(-2px);
      box-shadow: var(--shadow-hover);
    }
    .btn-outline-primary {
      border: 2px solid var(--primary);
      color: var(--primary);
      background: transparent;
    }
    .btn-outline-primary:hover {
      background-color: var(--primary);
      color: white;
    }
    .btn-outline-white {
      border: 2px solid white;
      color: white;
      background: transparent;
      font-weight: 600;
    }
    .btn-outline-white:hover {
      background-color: white;
      color: var(--primary);
    }
    h1, h2, h3, h4, h5 {
      font-weight: 700;
    }
    .section-title {
      font-size: 28px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 1rem;
      position: relative;
    }
    .section-title::after {
      content: "";
      display: block;
      width: 40px;
      height: 4px;
      background-color: var(--primary);
      margin-top: 0.5rem;
    }
    .section-title.text-center::after {
      margin-left: auto;
      margin-right: auto;
    }
    /* 导航 */
    .navbar {
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid var(--border-light);
      box-shadow: none;
      height: 64px;
      padding: 0 1rem;
    }
    .navbar-brand {
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--primary) !important;
    }
    .nav-link {
      color: var(--text-secondary) !important;
      font-weight: 500;
      font-size: 0.9rem;
      margin: 0 0.5rem;
      transition: var(--transition);
      position: relative;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--primary) !important;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.3s;
    }
    .nav-link:hover::after, .nav-link.active::after {
      width: 100%;
    }
    .search-icon {
      color: var(--text-secondary);
      font-size: 1.2rem;
      cursor: pointer;
      margin-right: 1rem;
    }
    .login-btn {
      background: transparent;
      border: none;
      color: var(--text-main);
      font-weight: 500;
      margin-right: 1rem;
    }
    .cta-nav-btn {
      background: var(--primary);
      color: white;
      border-radius: 50px;
      padding: 0.5rem 1.5rem;
      font-weight: 600;
      border: none;
    }
    /* Hero 双栏 */
    .hero-section {
      background: white;
      padding: 100px 0 80px;
    }
    .hero-title {
      font-size: 2.8rem;
      font-weight: 700;
      line-height: 1.2;
      color: var(--text-main);
    }
    .hero-title span {
      color: var(--primary);
    }
    .hero-subtitle {
      font-size: 1.1rem;
      color: var(--text-secondary);
      max-width: 480px;
      margin: 1.5rem 0 2rem;
    }
    .hero-image {
      border-radius: 16px;
      box-shadow: var(--shadow-md);
      position: relative;
      overflow: hidden;
    }
    .hero-image img {
      border-radius: 16px;
      aspect-ratio: 4/3;
      object-fit: cover;
    }
    /* 亮点卡片 */
    .highlight-card {
      background: var(--card-white);
      border-radius: var(--radius-lg);
      padding: 2rem;
      box-shadow: var(--shadow-md);
      transition: var(--transition);
      height: 100%;
      text-align: left;
    }
    .highlight-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .highlight-icon {
      font-size: 2.5rem;
      color: var(--primary);
      margin-bottom: 1rem;
    }
    /* 案例瀑布流网格 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
      gap: 24px;
    }
    .case-card {
      background: white;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .case-img {
      position: relative;
      overflow: hidden;
      aspect-ratio: 4/3;
    }
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.4s ease;
    }
    .case-card:hover .case-img img {
      transform: scale(1.03);
    }
    .case-overlay {
      position: absolute;
      top: 0; left: 0; width: 100%; height: 100%;
      background: rgba(26,95,206,0.2);
      opacity: 0;
      transition: 0.3s;
    }
    .case-card:hover .case-overlay {
      opacity: 1;
    }
    .case-info {
      padding: 1rem 1.2rem;
    }
    .case-tag {
      background: #E0F2FE;
      color: var(--primary);
      border-radius: 20px;
      padding: 2px 12px;
      font-size: 0.75rem;
    }
    /* 方案对比 */
    .compare-card {
      background: white;
      border-radius: var(--radius-lg);
      padding: 2.5rem;
      box-shadow: var(--shadow-md);
      height: 100%;
    }
    .compare-left {
      border: 1px solid var(--border-light);
    }
    .compare-right {
      border: 2px solid var(--primary);
    }
    .compare-item {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 1rem;
    }
    .badge-icon {
      width: 28px;
      height: 28px;
      border-radius: 50%;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-size: 14px;
      font-weight: bold;
    }
    /* FAQ */
    .accordion-button {
      font-weight: 600;
      font-size: 1.1rem;
      color: var(--text-main);
      background: transparent;
      box-shadow: none;
      border-bottom: 1px solid var(--border-light);
      padding: 1.2rem 0;
    }
    .accordion-button:not(.collapsed) {
      color: var(--primary);
      background: transparent;
      box-shadow: none;
    }
    .accordion-button::after {
      color: var(--primary);
    }
    /* CTA 横幅 */
    .cta-banner {
      background: linear-gradient(135deg, #1A5FCE 0%, #0EA5E9 100%);
      padding: 80px 0;
      text-align: center;
    }
    /* 页脚 */
    .footer {
      background: #1E293B;
      color: #CBD5E1;
      padding: 3rem 0 2rem;
    }
    .footer a {
      color: #CBD5E1;
      transition: 0.2s;
    }
    .footer a:hover {
      color: white;
    }
    .social-circle {
      width: 36px;
      height: 36px;
      background: rgba(255,255,255,0.15);
      border-radius: 50%;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      margin-right: 8px;
    }
    @media (max-width: 768px) {
      .hero-title {
        font-size: 2rem;
      }
      .navbar-brand {
        font-size: 1.2rem;
      }
    }