/* roulang page: index */
/* 自定义CSS变量与全局设计系统 */
    :root {
      --deep-blue: #0A0E27;
      --dark-bg: #0B1120;
      --card-bg: rgba(255, 255, 255, 0.04);
      --card-border: rgba(255, 255, 255, 0.08);
      --electric-blue: #3B82F6;
      --violet: #8B5CF6;
      --teal: #06B6D4;
      --text-primary: #F8FAFC;
      --text-secondary: #CBD5E1;
      --text-muted: #64748B;
      --glass-blur: 24px;
      --shadow-glow-blue: 0 0 20px rgba(59, 130, 246, 0.5);
      --shadow-glow-violet: 0 0 20px rgba(139, 92, 246, 0.5);
      --nav-width: 72px;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      background: radial-gradient(circle at 30% 20%, #1a1f3a 0%, #0A0E27 45%, #050812 100%);
      background-attachment: fixed;
      color: var(--text-secondary);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      display: flex;
      min-height: 100vh;
    }
    /* 左侧App Shell导航栏 */
    .app-nav {
      position: fixed;
      left: 0;
      top: 0;
      width: var(--nav-width);
      height: 100vh;
      background: rgba(5, 10, 26, 0.85);
      backdrop-filter: blur(40px);
      -webkit-backdrop-filter: blur(40px);
      border-right: 1px solid rgba(255, 255, 255, 0.06);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      padding: 2rem 0.5rem;
      z-index: 50;
      box-shadow: 4px 0 25px rgba(0,0,0,0.6);
    }
    .nav-logo {
      writing-mode: vertical-rl;
      text-orientation: mixed;
      font-weight: 800;
      font-size: 1.5rem;
      letter-spacing: 0.2em;
      color: var(--text-primary);
      background: linear-gradient(180deg, #3B82F6, #8B5CF6);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      margin-bottom: 1.5rem;
      user-select: none;
    }
    .nav-icons {
      display: flex;
      flex-direction: column;
      gap: 2rem;
      align-items: center;
      flex: 1;
      justify-content: center;
    }
    .nav-item {
      position: relative;
      width: 44px;
      height: 44px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 14px;
      color: var(--text-muted);
      transition: all 0.25s ease;
      background: transparent;
      cursor: pointer;
      font-size: 1.4rem;
    }
    .nav-item:hover {
      color: white;
      background: rgba(255,255,255,0.08);
      transform: translateX(4px);
    }
    .nav-item.active {
      color: white;
      background: rgba(59,130,246,0.15);
      box-shadow: inset 3px 0 0 var(--electric-blue);
    }
    .nav-tooltip {
      position: absolute;
      left: 58px;
      background: rgba(10,14,39,0.95);
      backdrop-filter: blur(12px);
      color: white;
      padding: 0.35rem 1rem;
      border-radius: 30px;
      font-size: 0.8rem;
      white-space: nowrap;
      opacity: 0;
      pointer-events: none;
      transition: 0.2s;
      border: 1px solid rgba(255,255,255,0.15);
    }
    .nav-item:hover .nav-tooltip {
      opacity: 1;
    }
    /* 主内容区域 */
    .main-content {
      margin-left: var(--nav-width);
      flex: 1;
      width: 100%;
      max-width: 1400px;
      padding: 0 2rem;
      position: relative;
    }
    /* 移动端顶部导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 60px;
      background: rgba(5,10,26,0.9);
      backdrop-filter: blur(30px);
      z-index: 55;
      align-items: center;
      padding: 0 1.5rem;
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }
    .hamburger {
      font-size: 1.8rem;
      color: white;
      background: none;
      border: none;
    }
    .mobile-drawer {
      position: fixed;
      top: 60px;
      left: 0;
      width: 100%;
      background: rgba(8,13,30,0.98);
      backdrop-filter: blur(30px);
      flex-direction: column;
      padding: 1.5rem;
      gap: 1.2rem;
      z-index: 54;
      display: none;
      border-bottom: 1px solid rgba(255,255,255,0.1);
    }
    .mobile-drawer a {
      color: #CBD5E1;
      font-size: 1.2rem;
      font-weight: 500;
      padding: 0.6rem 1rem;
      border-radius: 12px;
      display: block;
    }
    /* 通用组件 */
    .glass-card {
      background: var(--card-bg);
      backdrop-filter: blur(var(--glass-blur));
      -webkit-backdrop-filter: blur(var(--glass-blur));
      border: 1px solid var(--card-border);
      border-radius: 2rem;
      box-shadow: 0 25px 40px -15px rgba(0,0,0,0.6);
      transition: all 0.35s ease;
    }
    .glass-card:hover {
      transform: translateY(-6px);
      border-color: rgba(59,130,246,0.3);
      box-shadow: 0 30px 50px -10px rgba(59,130,246,0.2);
    }
    .btn-primary {
      background: var(--electric-blue);
      color: white;
      font-weight: 600;
      border-radius: 9999px;
      padding: 0.9rem 2.2rem;
      box-shadow: var(--shadow-glow-blue);
      transition: all 0.3s;
      display: inline-block;
      text-align: center;
      border: none;
      cursor: pointer;
      letter-spacing: 0.3px;
    }
    .btn-primary:hover {
      background: #4d94ff;
      box-shadow: 0 0 30px rgba(59,130,246,0.8);
      transform: scale(1.05);
    }
    .btn-glass {
      background: rgba(255,255,255,0.05);
      backdrop-filter: blur(12px);
      border: 1px solid rgba(255,255,255,0.2);
      color: white;
      border-radius: 9999px;
      padding: 0.9rem 2.2rem;
      font-weight: 500;
      transition: 0.3s;
    }
    .btn-glass:hover {
      background: rgba(255,255,255,0.15);
      border-color: rgba(255,255,255,0.4);
    }
    .section-title {
      font-size: 2.4rem;
      font-weight: 700;
      color: var(--text-primary);
      margin-bottom: 1rem;
      letter-spacing: -0.5px;
    }
    @media (max-width: 1024px) {
      .app-nav {
        display: none;
      }
      .main-content {
        margin-left: 0;
        padding: 0 1.5rem;
      }
      .mobile-header {
        display: flex;
        justify-content: space-between;
      }
      .section-title {
        font-size: 2rem;
      }
    }
    @media (max-width: 768px) {
      .main-content {
        padding: 0 1rem;
      }
    }