/* roulang page: index */
:root {
      --primary: #1A5FDC;
      --primary-deep: #0F3D8C;
      --accent: #F97316;
      --bg-light: #F8FAFC;
      --white: #FFFFFF;
      --text-dark: #0F172A;
      --text-secondary: #475569;
      --text-muted: #94A3B8;
      --border-light: #E2E8F0;
      --shadow-card: 0 1px 2px rgba(0,0,0,0.05);
      --shadow-hover: 0 10px 25px rgba(26,95,220,0.12);
      --shadow-hero: 0 20px 60px rgba(15,61,140,0.15);
      --nav-bg: #0F3D8C;
      --nav-text: #FFFFFF;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 4px;
      --radius-container: 16px;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: 'Inter', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      margin: 0;
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.6;
      display: flex;
      min-height: 100vh;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      color: inherit;
      text-decoration: none;
    }
    button, input, select, textarea {
      font-family: inherit;
    }
    /* 左侧导航 App Shell */
    .app-nav {
      position: fixed;
      left: 0;
      top: 0;
      height: 100vh;
      width: 72px;
      background-color: var(--nav-bg);
      color: var(--nav-text);
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 1.5rem 0;
      transition: width 0.25s ease;
      z-index: 50;
      overflow-x: hidden;
      white-space: nowrap;
      box-shadow: 2px 0 10px rgba(0,0,0,0.08);
    }
    .app-nav:hover {
      width: 240px;
      align-items: flex-start;
      padding-left: 1.2rem;
      padding-right: 1.2rem;
    }
    .nav-logo {
      display: flex;
      align-items: center;
      gap: 0.75rem;
      margin-bottom: 2.5rem;
      width: 100%;
      justify-content: center;
    }
    .app-nav:hover .nav-logo {
      justify-content: flex-start;
      padding-left: 0.5rem;
    }
    .logo-icon {
      width: 36px;
      height: 36px;
      background: linear-gradient(135deg, var(--primary) 0%, #3B82F6 100%);
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 20px;
      color: white;
      flex-shrink: 0;
      box-shadow: 0 4px 8px rgba(0,0,0,0.2);
    }
    .logo-text {
      font-weight: 700;
      font-size: 1.25rem;
      letter-spacing: 0.5px;
      display: none;
      color: white;
    }
    .app-nav:hover .logo-text {
      display: inline;
    }
    .nav-items {
      display: flex;
      flex-direction: column;
      width: 100%;
      gap: 0.3rem;
      flex: 1;
    }
    .nav-item {
      display: flex;
      align-items: center;
      gap: 1rem;
      padding: 0.8rem 0.6rem;
      border-radius: 10px;
      transition: background 0.2s;
      color: rgba(255,255,255,0.8);
      justify-content: center;
      position: relative;
      font-weight: 500;
    }
    .app-nav:hover .nav-item {
      justify-content: flex-start;
      padding-left: 1rem;
    }
    .nav-item i {
      font-size: 1.4rem;
      width: 24px;
      text-align: center;
    }
    .nav-item span {
      display: none;
      font-size: 0.95rem;
    }
    .app-nav:hover .nav-item span {
      display: inline;
    }
    .nav-item:hover {
      background: rgba(255,255,255,0.15);
      color: white;
    }
    .nav-item.active {
      color: white;
      background: rgba(255,255,255,0.1);
    }
    .nav-item.active::before {
      content: '';
      position: absolute;
      left: 0;
      top: 8px;
      bottom: 8px;
      width: 3px;
      background-color: var(--accent);
      border-radius: 0 4px 4px 0;
    }
    .status-indicator {
      margin-top: auto;
      display: flex;
      align-items: center;
      gap: 0.5rem;
      padding: 0.6rem;
      border-radius: 20px;
      background: rgba(255,255,255,0.1);
      font-size: 0.8rem;
      justify-content: center;
    }
    .app-nav:hover .status-indicator {
      justify-content: flex-start;
      padding-left: 1rem;
    }
    .live-dot {
      width: 10px;
      height: 10px;
      background-color: #10B981;
      border-radius: 50%;
      animation: pulse 1.5s infinite;
      box-shadow: 0 0 8px #10B981;
    }
    @keyframes pulse {
      0% { opacity: 1; transform: scale(1); }
      50% { opacity: 0.7; transform: scale(1.2); }
      100% { opacity: 1; transform: scale(1); }
    }
    .status-text {
      display: none;
      color: #E2E8F0;
    }
    .app-nav:hover .status-text {
      display: inline;
    }

    /* 主内容区域 */
    .main-content {
      margin-left: 72px;
      flex: 1;
      width: 100%;
    }

    /* 移动端导航 */
    .mobile-nav {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: white;
      z-index: 60;
      height: 64px;
      align-items: center;
      justify-content: space-between;
      padding: 0 1.5rem;
      box-shadow: 0 2px 8px rgba(0,0,0,0.05);
    }
    .drawer {
      position: fixed;
      top: 0;
      left: 0;
      width: 280px;
      height: 100vh;
      background: var(--nav-bg);
      z-index: 70;
      transform: translateX(-100%);
      transition: transform 0.3s ease;
      padding: 2rem 1.5rem;
      display: flex;
      flex-direction: column;
      color: white;
    }
    .drawer.open {
      transform: translateX(0);
    }
    .overlay {
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,0.5);
      z-index: 65;
      display: none;
    }
    .overlay.show {
      display: block;
    }

    @media (max-width: 1023px) {
      .app-nav {
        display: none;
      }
      .main-content {
        margin-left: 0;
        padding-top: 64px;
      }
      .mobile-nav {
        display: flex;
      }
    }

    /* 通用组件 */
    .container-custom {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 2rem;
    }
    .section-py {
      padding: 6rem 0;
    }
    .btn-primary {
      background-color: var(--accent);
      color: white;
      font-weight: 600;
      padding: 0.8rem 2rem;
      border-radius: var(--radius-btn);
      transition: all 0.2s;
      display: inline-block;
      box-shadow: 0 4px 10px rgba(249,115,22,0.3);
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background-color: #EA580C;
      box-shadow: 0 6px 18px rgba(249,115,22,0.4);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      font-weight: 600;
      padding: 0.7rem 1.8rem;
      border-radius: var(--radius-btn);
      transition: 0.2s;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }
    .section-title {
      font-size: 2.2rem;
      font-weight: 700;
      color: var(--text-dark);
      margin-bottom: 0.75rem;
    }
    .title-decor {
      width: 48px;
      height: 4px;
      background: var(--primary);
      margin-bottom: 2.5rem;
      border-radius: 2px;
    }
    .card {
      background: white;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: all 0.25s;
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }