/* roulang page: index */
:root {
      --primary: #F04E23;
      --primary-dark: #D03D1A;
      --secondary: #1E1E1E;
      --accent: #00E5FF;
      --bg-light: #F8F9FA;
      --white: #FFFFFF;
      --gray-100: #F1F3F5;
      --gray-200: #E9ECEF;
      --gray-500: #6C757D;
      --gray-700: #495057;
      --gray-900: #212529;
      --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-mono: "SF Mono", "Menlo", "Consolas", monospace;
      --border-radius-card: 12px;
      --border-radius-btn: 8px;
      --border-radius-input: 6px;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-card-hover: 0 12px 32px rgba(0,0,0,0.12);
      --transition-fast: 0.2s ease;
      --transition-smooth: 0.25s ease;
      --sidebar-width: 260px;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--gray-900);
      margin: 0;
      line-height: 1.8;
      overflow-x: hidden;
    }

    h1, h2, h3, h4, h5, h6 {
      font-weight: 700;
      line-height: 1.3;
    }

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

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

    /* 左侧导航 App Shell */
    .app-sidebar {
      position: fixed;
      top: 0;
      left: 0;
      width: var(--sidebar-width);
      height: 100vh;
      background-color: var(--secondary);
      color: rgba(255,255,255,0.85);
      display: flex;
      flex-direction: column;
      z-index: 1030;
      box-shadow: 2px 0 12px rgba(0,0,0,0.15);
      transition: transform var(--transition-smooth);
    }

    .sidebar-logo {
      height: 80px;
      display: flex;
      align-items: center;
      padding: 0 24px;
      border-bottom: 1px solid rgba(255,255,255,0.1);
      font-size: 1.8rem;
      font-weight: 800;
      letter-spacing: -0.5px;
      color: var(--white);
    }
    .sidebar-logo span {
      color: var(--accent);
      margin-left: 4px;
    }

    .sidebar-nav {
      flex: 1;
      padding: 24px 0;
      display: flex;
      flex-direction: column;
    }

    .sidebar-nav a {
      display: block;
      padding: 14px 24px;
      font-size: 0.95rem;
      font-weight: 500;
      color: rgba(255,255,255,0.7);
      border-left: 3px solid transparent;
      transition: all var(--transition-fast);
    }

    .sidebar-nav a:hover,
    .sidebar-nav a.active {
      background-color: rgba(240,78,35,0.15);
      color: var(--white);
      border-left-color: var(--accent);
    }

    .sidebar-footer {
      padding: 20px 24px;
      font-size: 0.8rem;
      color: rgba(255,255,255,0.5);
      border-top: 1px solid rgba(255,255,255,0.1);
    }

    /* 主内容区域 */
    .main-content {
      margin-left: var(--sidebar-width);
      width: calc(100% - var(--sidebar-width));
      background-color: var(--bg-light);
    }

    /* 移动端顶部导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 60px;
      background-color: var(--secondary);
      color: white;
      align-items: center;
      justify-content: space-between;
      padding: 0 20px;
      z-index: 1040;
    }

    .mobile-logo {
      font-size: 1.6rem;
      font-weight: 800;
      color: white;
    }
    .mobile-logo span {
      color: var(--accent);
    }

    .hamburger {
      font-size: 1.6rem;
      color: white;
      background: none;
      border: none;
    }

    /* 移动端抽屉菜单 */
    .mobile-drawer {
      position: fixed;
      top: 0;
      left: 0;
      width: 280px;
      height: 100vh;
      background-color: var(--secondary);
      z-index: 1050;
      transform: translateX(-100%);
      transition: transform 0.3s ease;
      display: flex;
      flex-direction: column;
      padding-top: 80px;
    }
    .mobile-drawer.open {
      transform: translateX(0);
    }
    .drawer-overlay {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: rgba(0,0,0,0.6);
      z-index: 1045;
      display: none;
    }
    .drawer-overlay.show {
      display: block;
    }
    .mobile-drawer a {
      display: block;
      padding: 16px 24px;
      color: rgba(255,255,255,0.8);
      font-size: 1.1rem;
      border-bottom: 1px solid rgba(255,255,255,0.1);
    }

    /* 区块通用 */
    .section-padding {
      padding: 5rem 0;
    }

    .section-title {
      font-size: 2.4rem;
      font-weight: 700;
      margin-bottom: 0.75rem;
    }
    .section-subtitle {
      font-size: 1.1rem;
      color: var(--gray-500);
      margin-bottom: 3rem;
    }

    /* 卡片样式 */
    .card-custom {
      background: var(--white);
      border: 1px solid var(--gray-200);
      border-radius: var(--border-radius-card);
      padding: 2rem;
      transition: all var(--transition-smooth);
      box-shadow: var(--shadow-card);
      height: 100%;
    }
    .card-custom:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-card-hover);
    }
    .icon-circle {
      width: 64px;
      height: 64px;
      background-color: rgba(0,229,255,0.1);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--accent);
      font-size: 1.8rem;
      margin-bottom: 1.5rem;
      transition: background var(--transition-fast);
    }
    .card-custom:hover .icon-circle {
      background-color: var(--primary);
      color: white;
    }

    /* 按钮 */
    .btn-primary-custom {
      background-color: var(--primary);
      border: none;
      color: white;
      padding: 12px 28px;
      border-radius: var(--border-radius-btn);
      font-weight: 600;
      transition: all var(--transition-fast);
      display: inline-block;
    }
    .btn-primary-custom:hover {
      background-color: var(--primary-dark);
      color: white;
    }
    .btn-outline-custom {
      background: transparent;
      border: 1px solid var(--primary);
      color: var(--primary);
      padding: 12px 28px;
      border-radius: var(--border-radius-btn);
      font-weight: 600;
      transition: all var(--transition-fast);
    }
    .btn-outline-custom:hover {
      background-color: var(--primary);
      color: white;
    }
    .btn-ghost {
      background: transparent;
      border: 1px solid white;
      color: white;
      padding: 12px 28px;
      border-radius: var(--border-radius-btn);
      font-weight: 600;
    }
    .btn-ghost:hover {
      background: white;
      color: var(--primary);
    }

    /* 数据数字 */
    .data-number {
      font-family: var(--font-mono);
      font-size: 3.2rem;
      font-weight: 800;
      color: var(--accent);
    }

    /* 手风琴定制 */
    .accordion-custom .accordion-item {
      border: none;
      border-bottom: 1px solid var(--gray-200);
      background: transparent;
    }
    .accordion-custom .accordion-button {
      font-weight: 600;
      font-size: 1.1rem;
      background: transparent;
      box-shadow: none;
      color: var(--gray-900);
      padding: 1.2rem 0;
    }
    .accordion-custom .accordion-button:not(.collapsed) {
      color: var(--primary);
      background: transparent;
    }
    .accordion-custom .accordion-button::after {
      transition: transform 0.2s ease;
    }
    .accordion-custom .accordion-body {
      color: var(--gray-700);
      line-height: 1.8;
      padding: 0 0 1.5rem;
    }

    /* 表单 */
    .form-control-custom {
      border-radius: var(--border-radius-input);
      border: 1px solid #CED4DA;
      padding: 0.75rem 1rem;
      transition: border-color 0.2s, box-shadow 0.2s;
    }
    .form-control-custom:focus {
      border-color: var(--accent);
      box-shadow: 0 0 0 0.2rem rgba(0,229,255,0.25);
    }

    /* 响应式 */
    @media (max-width: 991.98px) {
      .app-sidebar {
        display: none;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
      }
      .mobile-header {
        display: flex;
      }
      .section-title {
        font-size: 2rem;
      }
    }

    @media (max-width: 767.98px) {
      .section-title {
        font-size: 1.8rem;
      }
      .data-number {
        font-size: 2.4rem;
      }
    }