/* roulang page: index */
:root {
      --primary-deep: #0A1128;
      --primary-dark: #0B1A3B;
      --accent-cyan: #00E5FF;
      --accent-amber: #FFB300;
      --white: #FFFFFF;
      --gray-light: #B0C4DE;
      --gray-muted: #6b7a8f;
      --card-bg: rgba(255,255,255,0.05);
      --card-border: rgba(0,229,255,0.25);
      --glass-blur: blur(12px);
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --shadow-card: 0 8px 32px rgba(0,0,0,0.3), inset 0 1px 0 rgba(0,229,255,0.2);
      --transition: 0.3s ease;
      --nav-width: 240px;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: "Microsoft YaHei", "PingFang SC", "Helvetica Neue", Helvetica, Arial, sans-serif;
      background: radial-gradient(circle at 30% 10%, #0D1F3C, #0A1128 80%);
      color: var(--white);
      line-height: 1.7;
      overflow-x: hidden;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      color: var(--accent-cyan);
      text-decoration: none;
      transition: color var(--transition);
    }
    a:hover {
      color: var(--accent-amber);
      text-decoration: underline;
    }
    /* 左侧竖向导航 (桌面端) */
    .side-nav {
      position: fixed;
      left: 0;
      top: 0;
      width: var(--nav-width);
      height: 100vh;
      background: #0A1128;
      border-right: 1px solid rgba(0,229,255,0.25);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      z-index: 100;
      padding: 2rem 1.2rem;
      box-shadow: 4px 0 20px rgba(0,0,0,0.5);
    }
    .logo-area {
      font-size: 1.8rem;
      font-weight: 700;
      letter-spacing: 2px;
      text-shadow: 0 0 15px var(--accent-cyan);
      color: var(--accent-cyan);
      margin-bottom: 2.5rem;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo-icon {
      font-size: 2rem;
      filter: drop-shadow(0 0 8px var(--accent-cyan));
    }
    .nav-links {
      list-style: none;
      margin: 0;
      padding: 0;
      flex: 1;
    }
    .nav-links li {
      margin-bottom: 1.5rem;
    }
    .nav-links a {
      color: var(--gray-light);
      font-weight: 500;
      font-size: 1rem;
      display: flex;
      align-items: center;
      gap: 12px;
      padding: 0.5rem 0.8rem;
      border-radius: var(--radius-sm);
      transition: all var(--transition);
      text-decoration: none;
      border-left: 3px solid transparent;
    }
    .nav-links a i {
      width: 20px;
      text-align: center;
    }
    .nav-links a:hover {
      background: rgba(0,229,255,0.08);
      color: var(--accent-cyan);
      border-left: 3px solid var(--accent-cyan);
      text-decoration: none;
    }
    .nav-footer {
      font-size: 0.75rem;
      color: var(--gray-muted);
      border-top: 1px solid rgba(255,255,255,0.1);
      padding-top: 1.2rem;
    }
    /* 移动端顶部导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: #0A1128;
      border-bottom: 1px solid rgba(0,229,255,0.3);
      z-index: 99;
      padding: 0.8rem 1.2rem;
      justify-content: space-between;
      align-items: center;
      box-shadow: 0 4px 15px rgba(0,0,0,0.7);
    }
    .mobile-logo {
      font-size: 1.6rem;
      font-weight: 700;
      color: var(--accent-cyan);
      text-shadow: 0 0 10px var(--accent-cyan);
    }
    .hamburger {
      background: transparent;
      border: none;
      color: var(--accent-cyan);
      font-size: 1.8rem;
      cursor: pointer;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 60px;
      left: 0;
      width: 100%;
      background: rgba(10,17,40,0.97);
      backdrop-filter: blur(10px);
      padding: 1.5rem;
      flex-direction: column;
      gap: 1.5rem;
      border-bottom: 2px solid var(--accent-cyan);
      z-index: 98;
    }
    .mobile-menu a {
      color: var(--white);
      font-size: 1.1rem;
      padding: 0.5rem;
      border-left: 4px solid transparent;
      transition: 0.2s;
      text-decoration: none;
    }
    .mobile-menu a:hover {
      border-left: 4px solid var(--accent-cyan);
      color: var(--accent-cyan);
    }
    /* 主内容区 */
    .main-content {
      margin-left: var(--nav-width);
      width: calc(100% - var(--nav-width));
    }
    .container-custom {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 2rem;
    }
    section {
      padding: 5rem 0;
    }
    /* 玻璃拟态卡片 */
    .glass-card {
      background: var(--card-bg);
      backdrop-filter: var(--glass-blur);
      -webkit-backdrop-filter: var(--glass-blur);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      padding: 2rem;
      transition: all var(--transition);
    }
    .glass-card:hover {
      border-color: rgba(0,229,255,0.6);
      box-shadow: 0 12px 40px rgba(0,0,0,0.5), inset 0 1px 0 rgba(0,229,255,0.4);
      transform: translateY(-4px);
    }
    /* 按钮 */
    .btn-primary {
      background: var(--accent-cyan);
      color: #0A1128;
      font-weight: 700;
      padding: 0.8rem 2.2rem;
      border-radius: var(--radius-sm);
      border: none;
      box-shadow: 0 0 20px rgba(0,229,255,0.5);
      transition: all var(--transition);
      text-decoration: none;
      display: inline-block;
      cursor: pointer;
    }
    .btn-primary:hover {
      box-shadow: 0 0 30px rgba(0,229,255,0.8);
      background: #33eaff;
      color: #0A1128;
      text-decoration: none;
    }
    .btn-secondary {
      background: transparent;
      border: 1px solid var(--accent-cyan);
      color: white;
      padding: 0.7rem 1.8rem;
      border-radius: var(--radius-sm);
      transition: all var(--transition);
      text-decoration: none;
      display: inline-block;
    }
    .btn-secondary:hover {
      background: rgba(0,229,255,0.1);
      border-color: white;
      text-decoration: none;
      color: white;
    }
    .text-link {
      color: var(--accent-cyan);
      font-weight: 500;
      border-bottom: 1px dashed transparent;
      transition: 0.2s;
      text-decoration: none;
    }
    .text-link:hover {
      border-bottom: 1px dashed var(--accent-cyan);
      text-decoration: none;
    }
    h1, h2, h3 {
      font-weight: 700;
      line-height: 1.3;
    }
    h1 {
      font-size: 2.8rem;
      margin-bottom: 1.2rem;
    }
    h2 {
      font-size: 2rem;
      margin-bottom: 2.5rem;
      position: relative;
      display: inline-block;
    }
    h2:after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -8px;
      width: 60px;
      height: 3px;
      background: var(--accent-cyan);
      box-shadow: 0 0 10px var(--accent-cyan);
    }
    .accent-text {
      color: var(--accent-amber);
      font-weight: 700;
    }
    /* Hero数据看板 */
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2.5rem;
      align-items: center;
    }
    .metric-stack {
      display: flex;
      flex-direction: column;
      gap: 1.5rem;
    }
    .metric-item {
      display: flex;
      justify-content: space-between;
      align-items: baseline;
      border-bottom: 1px solid rgba(255,255,255,0.1);
      padding-bottom: 0.5rem;
    }
    .metric-number {
      font-size: 2.2rem;
      font-weight: 700;
      color: var(--accent-cyan);
      text-shadow: 0 0 8px rgba(0,229,255,0.6);
    }
    /* 服务网格 */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 2rem;
    }
    .service-icon {
      font-size: 2.2rem;
      color: var(--accent-cyan);
      margin-bottom: 1rem;
    }
    /*对比区域 */
    .compare-row {
      display: flex;
      flex-wrap: wrap;
      gap: 2rem;
      justify-content: center;
    }
    .compare-card {
      flex: 1 1 280px;
      background: rgba(255,255,255,0.03);
      border-radius: var(--radius-md);
      padding: 2rem;
      text-align: center;
    }
    .vs-badge {
      font-size: 1.6rem;
      font-weight: 700;
      color: var(--accent-amber);
    }
    /* FAQ手风琴覆盖 */
    .accordion {
      background: transparent;
    }
    .accordion-item {
      background: rgba(255,255,255,0.03);
      border: 1px solid rgba(0,229,255,0.2);
      border-radius: var(--radius-sm);
      margin-bottom: 12px;
      overflow: hidden;
    }
    .accordion-title {
      background: transparent;
      color: white;
      font-weight: 600;
      padding: 1.2rem;
      border: none;
      font-size: 1.1rem;
      transition: 0.2s;
    }
    .accordion-title:hover {
      color: var(--accent-cyan);
    }
    .accordion-content {
      background: rgba(0,0,0,0.3);
      color: var(--gray-light);
      padding: 1.2rem;
      border-top: 1px solid rgba(0,229,255,0.1);
    }
    /* 表单 */
    .input-field {
      background: transparent;
      border: 1px solid rgba(255,255,255,0.3);
      color: white;
      padding: 0.8rem;
      border-radius: var(--radius-sm);
      width: 100%;
      margin-bottom: 1rem;
    }
    .input-field:focus {
      outline: none;
      border-color: var(--accent-cyan);
      box-shadow: 0 0 8px rgba(0,229,255,0.4);
    }
    footer {
      background: #0A1128;
      padding: 3rem 0 1.5rem;
      border-top: 1px solid rgba(0,229,255,0.15);
    }
    /* 响应式 */
    @media (max-width: 1024px) {
      .hero-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
      }
      h1 {
        font-size: 2.2rem;
      }
    }
    @media (max-width: 768px) {
      .side-nav {
        display: none;
      }
      .mobile-header {
        display: flex;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
        padding-top: 70px;
      }
      .container-custom {
        padding: 0 1.5rem;
      }
      section {
        padding: 3.5rem 0;
      }
      h1 {
        font-size: 2rem;
      }
      h2 {
        font-size: 1.7rem;
      }
      .glass-card {
        padding: 1.5rem;
      }
      .metric-number {
        font-size: 1.8rem;
      }
    }