/* roulang page: index */
:root {
      --bg-primary: #0F0F14;
      --bg-card: rgba(26, 26, 34, 0.85);
      --accent-purple: #A855F7;
      --accent-cyan: #22D3EE;
      --text-primary: #E0E0E0;
      --text-secondary: #888888;
      --border-subtle: rgba(168, 85, 247, 0.15);
      --border-active: #A855F7;
      --radius-card: 12px;
      --radius-btn: 8px;
      --font-heading: 'Inter', system-ui, -apple-system, sans-serif;
      --font-mono: 'Space Grotesk', 'Courier New', monospace;
      --transition-fast: 0.25s ease;
      --glow-purple: 0 0 20px rgba(168, 85, 247, 0.25);
      --glow-cyan: 0 0 16px rgba(34, 211, 238, 0.3);
      --backdrop-blur: blur(16px);
    }

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

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

    body {
      background-color: var(--bg-primary);
      color: var(--text-primary);
      font-family: var(--font-heading);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航栏 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: rgba(15, 15, 20, 0.92);
      backdrop-filter: var(--backdrop-blur);
      -webkit-backdrop-filter: var(--backdrop-blur);
      border-bottom: 1px solid rgba(168, 85, 247, 0.2);
      z-index: 999;
      display: flex;
      align-items: center;
    }

    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }

    .logo {
      font-weight: 700;
      font-size: 1.4rem;
      color: var(--accent-cyan);
      display: flex;
      align-items: center;
      gap: 8px;
      letter-spacing: -0.3px;
    }

    .logo::before {
      content: '';
      display: inline-block;
      width: 10px;
      height: 10px;
      background: var(--accent-purple);
      border-radius: 2px;
      box-shadow: 0 0 12px var(--accent-purple);
    }

    .nav-menu {
      display: flex;
      gap: 32px;
      align-items: center;
    }

    .nav-link {
      font-size: 0.875rem;
      font-weight: 500;
      text-transform: uppercase;
      letter-spacing: 0.5px;
      color: #ccc;
      padding: 8px 0;
      position: relative;
    }

    .nav-link::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: 0;
      width: 0%;
      height: 2px;
      background: var(--accent-purple);
      transition: width 0.25s ease;
    }

    .nav-link:hover {
      color: white;
    }

    .nav-link:hover::after {
      width: 100%;
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      background: transparent;
      border: none;
      width: 32px;
      height: 24px;
      justify-content: center;
    }

    .hamburger span {
      display: block;
      height: 2px;
      background: white;
      border-radius: 4px;
      transition: 0.2s;
    }

    /* 移动端菜单 */
    .mobile-menu {
      position: fixed;
      top: 64px;
      left: 0;
      width: 100%;
      height: calc(100vh - 64px);
      background: #0F0F14;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      gap: 40px;
      display: none;
      z-index: 998;
    }

    .mobile-menu.active {
      display: flex;
    }

    .mobile-menu .nav-link {
      font-size: 1.8rem;
      font-weight: 600;
      text-transform: none;
    }

    /* Hero */
    .hero {
      min-height: 85vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      padding-top: 80px;
      background: radial-gradient(circle at 20% 30%, rgba(168,85,247,0.18) 0%, transparent 50%);
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 7fr 5fr;
      gap: 60px;
      align-items: center;
      width: 100%;
    }

    .hero-title {
      font-size: clamp(2.5rem, 5vw, 3.5rem);
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 20px;
      color: white;
    }

    .hero-sub {
      font-size: 1.25rem;
      color: #ccc;
      margin-bottom: 24px;
    }

    .hero-desc {
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 500px;
    }

    .btn-primary {
      background: var(--accent-purple);
      color: white;
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      display: inline-flex;
      align-items: center;
      gap: 10px;
      border: none;
      transition: background var(--transition-fast), box-shadow var(--transition-fast);
      font-size: 1rem;
    }

    .btn-primary:hover {
      background: var(--accent-cyan);
      color: #0F0F14;
      box-shadow: var(--glow-cyan);
    }

    .metrics-board {
      display: flex;
      flex-direction: column;
      gap: 28px;
      background: rgba(26,26,34,0.7);
      backdrop-filter: blur(12px);
      padding: 32px 28px;
      border-radius: var(--radius-card);
      border: 1px solid var(--border-subtle);
    }

    .metric-item {
      display: flex;
      flex-direction: column;
    }

    .metric-number {
      font-family: var(--font-mono);
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--accent-cyan);
      text-shadow: 0 0 16px rgba(34,211,238,0.4);
      animation: pulse-glow 2s infinite alternate;
    }

    @keyframes pulse-glow {
      0% { text-shadow: 0 0 8px rgba(34,211,238,0.3); }
      100% { text-shadow: 0 0 22px rgba(34,211,238,0.7); }
    }

    .metric-label {
      font-size: 0.9rem;
      color: var(--accent-purple);
      font-weight: 500;
      letter-spacing: 0.3px;
    }

    /* 通用板块 */
    section {
      padding: 100px 0;
    }

    .section-title {
      font-size: 2.2rem;
      font-weight: 600;
      margin-bottom: 48px;
      color: white;
      text-align: center;
    }

    /* 核心优势 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }

    .feature-card {
      background: var(--bg-card);
      backdrop-filter: blur(8px);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      transition: border 0.2s, box-shadow 0.2s;
    }

    .feature-card:hover {
      border-color: var(--accent-purple);
      box-shadow: var(--glow-purple);
    }

    .feature-number {
      font-family: var(--font-mono);
      font-size: 3rem;
      font-weight: 700;
      color: var(--accent-cyan);
    }

    .feature-label {
      font-weight: 600;
      color: var(--accent-purple);
      margin: 8px 0 12px;
    }

    /* 服务矩阵 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .service-card {
      background: var(--bg-card);
      backdrop-filter: blur(8px);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-card);
      padding: 36px 24px;
      transition: all 0.2s;
    }

    .service-card:hover {
      border-color: var(--accent-purple);
      box-shadow: var(--glow-purple);
    }

    .service-icon {
      font-size: 2.5rem;
      color: var(--accent-purple);
      margin-bottom: 20px;
    }

    .service-title {
      font-size: 1.4rem;
      font-weight: 600;
      margin-bottom: 12px;
    }

    .btn-outline {
      display: inline-block;
      border: 1px solid var(--accent-purple);
      color: var(--accent-purple);
      padding: 8px 20px;
      border-radius: var(--radius-btn);
      font-weight: 500;
      transition: 0.2s;
    }

    .btn-outline:hover {
      background: rgba(168,85,247,0.15);
    }

    /* 对比 */
    .comparison-container {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 0;
      border-radius: var(--radius-card);
      overflow: hidden;
    }

    .compare-left, .compare-right {
      padding: 48px 32px;
    }

    .compare-left {
      background: #2A1A1A;
    }

    .compare-right {
      background: #1E1A2A;
    }

    .compare-item {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 20px;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-subtle);
      padding: 24px 0;
    }

    .faq-question {
      font-weight: 600;
      font-size: 1.2rem;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: #aaa;
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 16px;
    }

    /* 表单 */
    .cta-form {
      background: radial-gradient(circle at center, rgba(168,85,247,0.2) 0%, transparent 70%);
      border-radius: var(--radius-card);
      padding: 60px 24px;
    }

    .form-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      margin-top: 40px;
    }

    .form-input {
      background: #1A1A22;
      border: none;
      border-bottom: 1px solid #444;
      padding: 14px 12px;
      color: white;
      border-radius: 6px;
      outline: none;
      transition: 0.2s;
    }

    .form-input:focus {
      border-color: var(--accent-purple);
      box-shadow: 0 0 10px var(--accent-purple);
    }

    .footer {
      border-top: 1px solid rgba(168,85,247,0.2);
      padding: 32px 0;
    }

    @media (max-width: 1023px) {
      .hero-grid { grid-template-columns: 1fr; }
      .features-grid { grid-template-columns: repeat(2, 1fr); }
      .services-grid { grid-template-columns: repeat(2, 1fr); }
      .comparison-container { grid-template-columns: 1fr; }
      .form-grid { grid-template-columns: repeat(2, 1fr); }
    }

    @media (max-width: 640px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .features-grid, .services-grid { grid-template-columns: 1fr; }
      .form-grid { grid-template-columns: 1fr; }
    }