/* roulang page: index */
:root {
      --primary-deep: #1E2A4F;
      --primary-gradient: linear-gradient(135deg, #1E2A4F 0%, #2A3A6A 100%);
      --accent-coral: #FF6B5B;
      --accent-coral-hover: #E85D4F;
      --bg-light: #F8F9FC;
      --white: #FFFFFF;
      --text-primary: #1E2A4F;
      --text-secondary: #5A627A;
      --text-muted: #8A90A5;
      --border-light: #E9ECF2;
      --shadow-sm: 0 4px 20px rgba(0, 0, 0, 0.04);
      --shadow-hover: 0 12px 32px rgba(0, 0, 0, 0.08);
      --radius-card: 16px;
      --radius-btn: 8px;
      --sidebar-width: 240px;
      --transition: 0.3s ease;
      --font-sans: -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-primary);
      line-height: 1.6;
      margin: 0;
      overflow-x: hidden;
    }
    h1, h2, h3, h4, .h1, .h2, .h3, .h4 {
      font-weight: 600;
      line-height: 1.3;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    /* 自定义 Bootstrap 覆盖 */
    .btn {
      border-radius: var(--radius-btn);
      padding: 12px 28px;
      font-weight: 500;
      transition: var(--transition);
      border: none;
    }
    .btn-primary {
      background-color: var(--accent-coral);
      border-color: var(--accent-coral);
      color: white;
    }
    .btn-primary:hover, .btn-primary:focus {
      background-color: var(--accent-coral-hover);
      border-color: var(--accent-coral-hover);
      transform: scale(1.02);
      box-shadow: 0 8px 20px rgba(255, 107, 91, 0.3);
    }
    .btn-outline-secondary {
      border: 1px solid var(--primary-deep);
      color: var(--primary-deep);
      background: transparent;
    }
    .btn-outline-secondary:hover {
      background-color: rgba(30, 42, 79, 0.05);
      border-color: var(--primary-deep);
      color: var(--primary-deep);
    }
    .card {
      border: none;
      border-radius: var(--radius-card);
      background: var(--white);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    /* 左侧导航 App Shell */
    .app-sidebar {
      position: fixed;
      left: 0;
      top: 0;
      width: var(--sidebar-width);
      height: 100vh;
      background: var(--primary-deep);
      display: flex;
      flex-direction: column;
      z-index: 1030;
      box-shadow: 4px 0 20px rgba(0,0,0,0.08);
      transition: transform 0.3s ease;
    }
    .sidebar-brand {
      padding: 28px 24px;
      color: white;
      font-size: 1.8rem;
      font-weight: 700;
      letter-spacing: 1px;
      border-bottom: 1px solid rgba(255,255,255,0.1);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .sidebar-brand i {
      color: var(--accent-coral);
      font-size: 2rem;
    }
    .sidebar-nav {
      flex: 1;
      padding: 32px 16px;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }
    .sidebar-nav a {
      color: rgba(255,255,255,0.7);
      padding: 12px 20px;
      border-radius: 8px;
      font-size: 1rem;
      font-weight: 400;
      transition: 0.2s;
      display: block;
      position: relative;
    }
    .sidebar-nav a:hover, .sidebar-nav a.active {
      color: white;
      background: rgba(255,255,255,0.08);
      border-left: 3px solid var(--accent-coral);
      padding-left: 17px;
    }
    .sidebar-footer {
      padding: 24px;
      border-top: 1px solid rgba(255,255,255,0.1);
      color: rgba(255,255,255,0.6);
      font-size: 0.85rem;
    }
    /* 主内容区偏移 */
    .main-content {
      margin-left: var(--sidebar-width);
      background: var(--bg-light);
    }
    /* 移动端顶部导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: var(--primary-deep);
      z-index: 1040;
      padding: 14px 20px;
      justify-content: space-between;
      align-items: center;
      color: white;
    }
    .mobile-toggle {
      background: none;
      border: none;
      color: white;
      font-size: 1.8rem;
    }
    /* 抽屉菜单 */
    .mobile-drawer {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: var(--primary-deep);
      z-index: 1050;
      transform: translateX(-100%);
      transition: transform 0.3s ease;
      display: flex;
      flex-direction: column;
      padding: 24px;
    }
    .mobile-drawer.show {
      transform: translateX(0);
    }
    .mobile-drawer .close-btn {
      align-self: flex-end;
      background: none;
      border: none;
      color: white;
      font-size: 2rem;
    }
    .mobile-drawer a {
      color: rgba(255,255,255,0.8);
      padding: 16px 20px;
      font-size: 1.2rem;
      border-bottom: 1px solid rgba(255,255,255,0.1);
    }
    /* Hero */
    #hero {
      background: var(--primary-gradient);
      position: relative;
      overflow: hidden;
    }
    #hero::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: radial-gradient(circle at 30% 40%, rgba(255,255,255,0.05) 0%, transparent 30%);
    }
    .hero-img {
      border-radius: 24px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.3);
    }
    /* 数据徽章 */
    .stat-number {
      font-size: 3rem;
      font-weight: 800;
      color: var(--accent-coral);
      line-height: 1.1;
    }
    .stat-label {
      color: var(--text-muted);
      font-size: 0.9rem;
    }
    /* FAQ手风琴 */
    .accordion-button {
      font-weight: 600;
      background: white;
      box-shadow: none;
      border-radius: var(--radius-card) !important;
      padding: 20px 24px;
    }
    .accordion-button:not(.collapsed) {
      background: white;
      color: var(--primary-deep);
      border-left: 4px solid var(--accent-coral);
    }
    .accordion-item {
      border: none;
      margin-bottom: 16px;
      border-radius: var(--radius-card);
      background: transparent;
    }
    /* 表单 */
    .form-control {
      border-radius: 8px;
      border: 1px solid var(--border-light);
      padding: 12px 16px;
    }
    .form-control:focus {
      border-color: var(--accent-coral);
      box-shadow: 0 0 0 3px rgba(255,107,91,0.15);
    }
    /* 响应式 */
    @media (max-width: 992px) {
      .app-sidebar {
        transform: translateX(-100%);
      }
      .main-content {
        margin-left: 0;
      }
      .mobile-header {
        display: flex;
      }
      #hero .row {
        flex-direction: column;
        text-align: center;
      }
    }
    @media (min-width: 993px) {
      .mobile-header, .mobile-drawer {
        display: none !important;
      }
    }