/* roulang page: index */
:root {
      --deep-ocean: #0A1128;
      --dark-blue: #1A1F3A;
      --ice-blue: #00E5FF;
      --aurora-purple: #7B2FBE;
      --card-bg: rgba(255, 255, 255, 0.04);
      --glass-border: rgba(0, 229, 255, 0.15);
      --text-light: #FFFFFF;
      --text-gray: #B0C4DE;
      --text-dim: #6A7B9A;
      --radius-card: 16px;
      --radius-inner: 12px;
      --radius-pill: 50px;
      --shadow-glow: 0 8px 32px rgba(0, 229, 255, 0.08);
      --shadow-hover: 0 12px 40px rgba(0, 229, 255, 0.25);
      --transition: all 0.3s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Inter', system-ui, -apple-system, sans-serif;
      background: radial-gradient(circle at 20% 20%, #1A1F3A, #0A1128);
      color: var(--text-gray);
      margin: 0;
      line-height: 1.8;
      overflow-x: hidden;
      min-height: 100vh;
    }

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

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

    button, input {
      font-family: inherit;
    }

    /* App Shell 布局 */
    .app-shell {
      display: flex;
      min-height: 100vh;
    }

    /* 左侧固定导航 */
    .sidebar {
      width: 240px;
      background: rgba(10, 17, 40, 0.9);
      backdrop-filter: blur(24px);
      -webkit-backdrop-filter: blur(24px);
      border-right: 1px solid rgba(0, 229, 255, 0.2);
      display: flex;
      flex-direction: column;
      position: fixed;
      top: 0;
      left: 0;
      bottom: 0;
      z-index: 1040;
      padding: 2rem 1rem;
      box-shadow: 4px 0 20px rgba(0,0,0,0.6);
    }

    .logo-area {
      display: flex;
      align-items: center;
      gap: 10px;
      margin-bottom: 2.5rem;
      padding-left: 0.5rem;
    }

    .logo-icon {
      font-size: 2rem;
      color: var(--ice-blue);
      filter: drop-shadow(0 0 12px rgba(0,229,255,0.6));
    }

    .logo-text {
      font-size: 1.6rem;
      font-weight: 700;
      background: linear-gradient(135deg, #00E5FF 0%, #7B2FBE 80%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      letter-spacing: 0.02em;
    }

    .nav-menu {
      list-style: none;
      padding: 0;
      margin: 0;
      flex: 1;
    }

    .nav-item {
      margin-bottom: 0.5rem;
    }

    .nav-link {
      display: flex;
      align-items: center;
      gap: 0.8rem;
      padding: 0.8rem 1rem;
      border-radius: 10px;
      color: var(--text-dim);
      font-weight: 500;
      font-size: 0.95rem;
      border-left: 3px solid transparent;
      transition: var(--transition);
    }

    .nav-link i {
      width: 20px;
      font-size: 1.1rem;
    }

    .nav-link:hover, .nav-link.active {
      background: rgba(0, 229, 255, 0.08);
      color: var(--ice-blue);
      border-left: 3px solid var(--ice-blue);
      text-shadow: 0 0 6px rgba(0,229,255,0.5);
    }

    /* 主内容区 */
    .main-content {
      margin-left: 240px;
      flex: 1;
      width: calc(100% - 240px);
    }

    /* 移动端顶部栏 */
    .mobile-header {
      display: none;
      height: 56px;
      background: rgba(10, 17, 40, 0.95);
      backdrop-filter: blur(20px);
      position: fixed;
      top: 0;
      left: 0;
      right: 0;
      z-index: 1050;
      align-items: center;
      justify-content: space-between;
      padding: 0 1.2rem;
      border-bottom: 1px solid rgba(0,229,255,0.25);
    }

    .hamburger {
      font-size: 1.6rem;
      color: var(--ice-blue);
      background: none;
      border: none;
    }

    /* 抽屉菜单 */
    .drawer {
      position: fixed;
      top: 0;
      left: -280px;
      width: 260px;
      height: 100%;
      background: rgba(10,17,40,0.98);
      backdrop-filter: blur(28px);
      z-index: 1100;
      padding: 2rem 1rem;
      transition: left 0.3s ease;
      border-right: 1px solid var(--ice-blue);
    }
    .drawer.open {
      left: 0;
    }
    .drawer .nav-link {
      color: var(--text-light);
    }

    /* 通用区块 */
    .section-block {
      padding: 6rem 2rem;
      scroll-margin-top: 60px;
    }

    .glass-card {
      background: var(--card-bg);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-glow);
    }

    h1 {
      font-size: 2.8rem;
      font-weight: 700;
      letter-spacing: 0.02em;
      background: linear-gradient(to right, #00E5FF, #7B2FBE);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    h2 {
      font-size: 2rem;
      font-weight: 600;
      color: var(--text-light);
      margin-bottom: 2rem;
    }

    h3 {
      font-size: 1.4rem;
      font-weight: 600;
      color: var(--ice-blue);
    }

    .text-glow-blue {
      color: var(--ice-blue);
      text-shadow: 0 0 15px rgba(0,229,255,0.6);
    }

    .btn-primary-glow {
      background: var(--ice-blue);
      color: #0A1128;
      font-weight: 700;
      border-radius: var(--radius-pill);
      padding: 0.75rem 2.2rem;
      border: none;
      box-shadow: 0 0 24px rgba(0,229,255,0.5);
      transition: 0.3s;
      letter-spacing: 0.5px;
    }
    .btn-primary-glow:hover {
      box-shadow: 0 0 40px rgba(0,229,255,0.8);
      transform: scale(1.05);
      background: #33eaff;
      color: #000;
    }

    .btn-outline-ice {
      background: transparent;
      border: 1.5px solid var(--ice-blue);
      color: var(--ice-blue);
      border-radius: 30px;
      padding: 0.5rem 1.8rem;
      font-weight: 500;
    }
    .btn-outline-ice:hover {
      background: rgba(0,229,255,0.1);
      color: #fff;
      border-color: #fff;
    }

    /* Hero */
    .hero-bg {
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
    }

    /* 数据指标数字 */
    .metric-number {
      font-size: 3rem;
      font-weight: 700;
      color: var(--ice-blue);
      text-shadow: 0 0 20px rgba(0,229,255,0.7);
    }

    /* 服务卡片 */
    .service-card {
      transition: 0.35s;
    }
    .service-card:hover {
      transform: translateY(-6px);
      border-color: var(--ice-blue);
      box-shadow: var(--shadow-hover);
    }

    /* FAQ */
    .accordion-button {
      background: rgba(20, 30, 55, 0.7);
      backdrop-filter: blur(12px);
      color: #fff;
      font-weight: 600;
      border: 1px solid rgba(0,229,255,0.2);
    }
    .accordion-button:not(.collapsed) {
      background: rgba(0,229,255,0.15);
      color: var(--ice-blue);
      border-color: var(--ice-blue);
      box-shadow: 0 0 18px rgba(0,229,255,0.3);
    }
    .accordion-body {
      background: rgba(0,0,0,0.3);
      color: #B0C4DE;
    }

    footer {
      background: #060B1C;
      border-top: 1px solid rgba(0,229,255,0.2);
    }

    @media (max-width: 992px) {
      .sidebar {
        display: none;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
      }
      .mobile-header {
        display: flex;
      }
      h1 {
        font-size: 2.2rem;
      }
      .metric-number {
        font-size: 2.5rem;
      }
    }