/* roulang page: index */
:root {
      --primary: #0A66FF;
      --primary-glow: rgba(10,102,255,0.5);
      --accent: #FF6B2B;
      --accent-glow: rgba(255,107,43,0.5);
      --bg-deep: #0B0E14;
      --bg-charcoal: #1A1D26;
      --text-high: #E8ECF1;
      --text-muted: #8B95A5;
      --border-subtle: rgba(255,255,255,0.08);
      --border-active: rgba(10,102,255,0.3);
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --shadow-card: 0 8px 32px rgba(0,0,0,0.4);
      --shadow-hover: 0 16px 48px rgba(10,102,255,0.15);
      --transition: 0.3s ease;
      --font-title: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
      --font-body: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
      --font-number: 'DIN Alternate', 'PingFang SC', sans-serif;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-body);
      background-color: var(--bg-deep);
      color: var(--text-high);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(11,14,20,0.85);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border-bottom: 1px solid transparent;
      background-image: linear-gradient(rgba(11,14,20,0.85), rgba(11,14,20,0.85)), linear-gradient(to right, var(--primary), transparent);
      background-origin: border-box;
      background-clip: padding-box, border-box;
      z-index: 1000;
      transition: var(--transition);
    }

    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }

    .logo {
      font-family: var(--font-title);
      font-weight: 700;
      font-size: 24px;
      color: #fff;
      text-decoration: none;
      letter-spacing: 2px;
      text-shadow: 0 0 12px rgba(10,102,255,0.6);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo-icon {
      width: 28px;
      height: 28px;
      background: var(--primary);
      border-radius: 6px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: bold;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 40px;
      list-style: none;
    }

    .nav-links a {
      color: var(--text-muted);
      text-decoration: none;
      font-size: 16px;
      font-weight: 500;
      position: relative;
      padding: 8px 0;
      transition: color 0.2s;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%);
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.25s ease;
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: #fff;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .btn-primary {
      background: var(--primary);
      color: #fff;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      text-decoration: none;
      box-shadow: 0 0 20px var(--primary-glow), 0 0 40px rgba(10,102,255,0.2);
      transition: all 0.2s;
      border: none;
      cursor: pointer;
      display: inline-block;
      text-align: center;
      white-space: nowrap;
    }
    .btn-primary:hover {
      background: #1A75FF;
      box-shadow: 0 0 30px rgba(10,102,255,0.8);
      transform: translateY(-1px);
    }

    .btn-outline {
      background: transparent;
      border: 1px solid rgba(255,255,255,0.3);
      color: #fff;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      text-decoration: none;
      transition: all 0.2s;
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }
    .btn-outline:hover {
      border-color: var(--primary);
      color: #fff;
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: transparent;
      border: none;
      cursor: pointer;
      padding: 8px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: #fff;
      transition: 0.3s;
    }

    /* Hero */
    .hero {
      padding: 160px 0 100px;
      background-color: var(--bg-deep);
      background-image: radial-gradient(circle at 25% 0%, rgba(10,102,255,0.08) 0%, transparent 50%);
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-left {
      flex: 1;
    }
    .hero-right {
      flex: 1;
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }

    .hero h1 {
      font-family: var(--font-title);
      font-size: 48px;
      font-weight: 700;
      letter-spacing: -0.5px;
      line-height: 1.2;
      margin-bottom: 24px;
    }
    .highlight {
      color: var(--primary);
    }
    .hero-sub {
      color: var(--text-muted);
      font-size: 18px;
      margin-bottom: 36px;
      max-width: 480px;
    }

    .stat-card {
      background: rgba(255,255,255,0.03);
      backdrop-filter: blur(20px);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-lg);
      padding: 24px 20px;
      width: calc(33.333% - 14px);
      text-align: center;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .stat-number {
      font-family: var(--font-number);
      font-size: 32px;
      font-weight: 700;
      color: #fff;
    }
    .stat-label {
      color: var(--text-muted);
      font-size: 13px;
      margin-top: 8px;
    }

    /* 通用板块 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-family: var(--font-title);
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 20px;
      text-align: center;
    }
    .section-desc {
      color: var(--text-muted);
      text-align: center;
      max-width: 640px;
      margin: 0 auto 60px;
      font-size: 18px;
    }

    /* 核心优势 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }
    .feature-card {
      background: rgba(255,255,255,0.03);
      backdrop-filter: blur(20px);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-lg);
      padding: 36px 28px;
      transition: var(--transition);
      box-shadow: var(--shadow-card);
      text-align: left;
    }
    .feature-card:hover {
      transform: translateY(-6px);
      border-color: var(--border-active);
      box-shadow: var(--shadow-hover);
    }
    .feature-icon {
      font-size: 28px;
      color: var(--primary);
      margin-bottom: 20px;
    }
    .feature-card h3 {
      font-size: 22px;
      font-weight: 600;
      margin-bottom: 14px;
    }
    .feature-card p {
      color: var(--text-muted);
      font-size: 15px;
    }

    /* 服务矩阵 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }
    .service-card {
      background: rgba(255,255,255,0.03);
      backdrop-filter: blur(20px);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-lg);
      overflow: hidden;
      transition: var(--transition);
      box-shadow: var(--shadow-card);
    }
    .service-card:hover {
      transform: translateY(-4px);
      border-color: var(--border-active);
      box-shadow: var(--shadow-hover);
    }
    .service-img {
      height: 180px;
      background-color: #1A1D26;
      background-size: cover;
      background-position: center;
      position: relative;
      overflow: hidden;
    }
    .service-img::after {
      content: '';
      position: absolute;
      inset: 0;
      background: rgba(10,102,255,0.15);
      opacity: 0;
      transition: 0.3s;
    }
    .service-card:hover .service-img::after {
      opacity: 1;
    }
    .service-content {
      padding: 24px;
    }
    .service-tag {
      font-size: 12px;
      background: var(--primary);
      color: white;
      padding: 4px 10px;
      border-radius: 20px;
      display: inline-block;
      margin-bottom: 12px;
    }
    .service-card h3 {
      font-size: 20px;
      font-weight: 600;
    }

    /* 对比区 */
    .compare-wrapper {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 30px;
      flex-wrap: wrap;
    }
    .compare-col {
      flex: 1;
      min-width: 280px;
      background: rgba(255,255,255,0.03);
      backdrop-filter: blur(20px);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-lg);
      padding: 36px 28px;
    }
    .vs-circle {
      width: 48px;
      height: 48px;
      border: 2px solid var(--primary);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: bold;
      color: var(--primary);
      background: #0B0E14;
    }
    .compare-item {
      display: flex;
      align-items: center;
      gap: 12px;
      margin: 18px 0;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.05);
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 20px 0;
      cursor: pointer;
      font-size: 18px;
      font-weight: 600;
    }
    .faq-icon {
      font-size: 20px;
      color: var(--primary);
      transition: 0.3s;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-muted);
      font-size: 16px;
      padding: 0 0 0 8px;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding-bottom: 20px;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }

    /* 底部转化 */
    .cta-section {
      background: #0A0E17;
    }
    .cta-grid {
      display: flex;
      gap: 60px;
      align-items: center;
      flex-wrap: wrap;
    }
    .cta-left {
      flex: 1;
    }
    .cta-right {
      flex: 1;
    }
    .input-glass {
      background: rgba(255,255,255,0.04);
      border: 1px solid rgba(255,255,255,0.1);
      border-radius: 8px;
      padding: 14px 16px;
      width: 100%;
      color: #fff;
      margin-bottom: 16px;
      transition: 0.2s;
    }
    .input-glass:focus {
      outline: none;
      border-color: var(--primary);
    }
    .btn-accent {
      background: var(--accent);
      color: #fff;
      padding: 14px 28px;
      border: none;
      border-radius: 8px;
      font-weight: 600;
      box-shadow: 0 0 20px var(--accent-glow);
      cursor: pointer;
      width: 100%;
    }

    /* 页脚 */
    .footer {
      background: #0B0E14;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .footer a {
      color: var(--text-muted);
      text-decoration: none;
    }
    .footer a:hover {
      color: var(--primary);
    }

    @media (max-width: 1024px) {
      .hero-grid, .cta-grid {
        flex-direction: column;
      }
      .features-grid, .services-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .hero h1 {
        font-size: 36px;
      }
      .features-grid, .services-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 480px) {
      .hero h1 {
        font-size: 32px;
      }
      .section-title {
        font-size: 28px;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }