/* roulang page: index */
:root {
      --primary: #00F0FF;
      --primary-glow: rgba(0, 240, 255, 0.5);
      --secondary: #FF6B35;
      --secondary-glow: rgba(255, 107, 53, 0.6);
      --bg-deep: #0A0E17;
      --bg-card: rgba(19, 26, 38, 0.7);
      --bg-card-solid: #131A26;
      --bg-container: #1C2536;
      --text-primary: #FFFFFF;
      --text-body: #B0C4DE;
      --text-muted: #6B7B8D;
      --success: #00E676;
      --warning: #FF5252;
      --border-dim: rgba(0, 240, 255, 0.15);
      --border-glow: rgba(0, 240, 255, 0.4);
      --radius-lg: 20px;
      --radius-md: 16px;
      --radius-sm: 12px;
      --radius-pill: 40px;
      --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.45);
      --shadow-glow: 0 0 20px rgba(0, 240, 255, 0.45), 0 0 40px rgba(0, 240, 255, 0.15);
      --font-heading: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-number: "DIN Alternate", "Oswald", sans-serif;
      --transition: 0.3s ease;
      --max-width: 1200px;
      --header-height: 72px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-heading);
      background-color: var(--bg-deep);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    h1, h2, h3, h4 {
      color: var(--text-primary);
      font-weight: 700;
    }
    h1 {
      font-size: 48px;
      letter-spacing: -0.5px;
      line-height: 1.2;
    }
    h2 {
      font-size: 36px;
      margin-bottom: 16px;
    }
    h3 {
      font-size: 20px;
      font-weight: 600;
    }
    a {
      color: var(--primary);
      text-decoration: none;
      transition: var(--transition);
    }
    a:hover {
      color: #7bf5ff;
    }
    img {
      max-width: 100%;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: transparent;
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      font-weight: 600;
    }
    /* 玻璃拟态核心 */
    .glass {
      background: var(--bg-card);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border: 1px solid var(--border-dim);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
    }
    .glass-hover:hover {
      border-color: var(--border-glow);
      box-shadow: 0 12px 36px rgba(0, 240, 255, 0.2);
      transform: translateY(-4px);
    }
    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      height: var(--header-height);
      display: flex;
      align-items: center;
      background: transparent;
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(0, 240, 255, 0.08);
      transition: background 0.3s, box-shadow 0.3s;
    }
    .navbar.scrolled {
      background: rgba(10, 14, 23, 0.92);
      box-shadow: 0 4px 24px rgba(0,0,0,0.5);
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 24px;
      font-weight: 700;
      color: var(--text-primary);
      letter-spacing: 1px;
    }
    .logo-icon {
      font-size: 32px;
      background: linear-gradient(135deg, var(--primary), var(--secondary));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      color: var(--text-body);
      font-weight: 500;
      font-size: 16px;
      position: relative;
      padding: 8px 0;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      box-shadow: 0 0 10px var(--primary);
      transition: width 0.25s;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .mobile-nav {
      display: none;
      position: fixed;
      bottom: 16px;
      left: 50%;
      transform: translateX(-50%);
      width: calc(100% - 32px);
      max-width: 500px;
      background: rgba(19, 26, 38, 0.85);
      backdrop-filter: blur(20px);
      border: 1px solid var(--border-dim);
      border-radius: 40px;
      padding: 8px 20px;
      justify-content: space-around;
      z-index: 1001;
      box-shadow: 0 8px 30px rgba(0,0,0,0.6);
    }
    .mobile-nav a {
      color: var(--text-muted);
      font-size: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 4px;
    }
    .mobile-nav a i {
      font-size: 20px;
    }
    .mobile-nav .cta-mobile {
      background: var(--primary);
      color: #0A0E17;
      border-radius: 30px;
      padding: 6px 18px;
      font-weight: 700;
      box-shadow: 0 0 18px var(--primary-glow);
    }
    /* 按钮 */
    .btn-primary {
      background: var(--primary);
      color: #0A0E17;
      padding: 14px 32px;
      border-radius: var(--radius-pill);
      font-weight: 700;
      box-shadow: 0 0 20px var(--primary-glow);
      border: none;
    }
    .btn-primary:hover {
      box-shadow: 0 0 32px rgba(0, 240, 255, 0.8);
      background: #2df5ff;
      transform: translateY(-2px);
    }
    .btn-secondary {
      background: var(--secondary);
      color: #fff;
      padding: 14px 32px;
      border-radius: var(--radius-pill);
      box-shadow: 0 0 20px var(--secondary-glow);
    }
    .btn-outline {
      border: 1px solid var(--border-dim);
      color: var(--text-primary);
      padding: 12px 28px;
      border-radius: var(--radius-pill);
      background: rgba(255,255,255,0.02);
    }
    .btn-outline:hover {
      border-color: var(--primary);
      background: rgba(0,240,255,0.05);
    }
    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      background: radial-gradient(circle at 30% 40%, #0f1a2b, #0A0E17);
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
      width: 100%;
    }
    .hero-left {
      flex: 1;
    }
    .hero-right {
      flex: 1;
      position: relative;
    }
    .hero-badge {
      background: rgba(0,240,255,0.1);
      border: 1px solid var(--primary);
      color: var(--primary);
      padding: 6px 16px;
      border-radius: 20px;
      font-size: 14px;
      display: inline-block;
      margin-bottom: 24px;
    }
    .particles {
      position: absolute;
      width: 100%;
      height: 100%;
      top: 0;
      left: 0;
      pointer-events: none;
    }
    /* 核心优势错位卡片 */
    .advantages-grid {
      display: flex;
      flex-wrap: wrap;
      gap: 24px;
      justify-content: center;
    }
    .adv-card {
      flex: 1 1 280px;
      max-width: 340px;
      padding: 32px;
      background: var(--bg-card);
      backdrop-filter: blur(14px);
      border: 1px solid var(--border-dim);
      border-radius: 28px;
      position: relative;
    }
    .adv-card:nth-child(1) { margin-top: 0; }
    .adv-card:nth-child(2) { margin-top: 40px; }
    .adv-card:nth-child(3) { margin-top: 20px; }
    /* 功能网格 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-card {
      padding: 28px;
      text-align: left;
    }
    /* 场景卡片 */
    .scenarios {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 16px;
    }
    .scenario-card {
      min-width: 300px;
      flex: 1;
      border-radius: 24px;
      overflow: hidden;
      position: relative;
    }
    .scenario-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }
    /* 案例 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    .case-card {
      display: flex;
      gap: 20px;
      padding: 24px;
    }
    .avatar {
      width: 60px;
      height: 60px;
      border-radius: 50%;
      background: var(--bg-container);
      border: 2px solid var(--primary);
    }
    /* 价格 */
    .pricing-grid {
      display: flex;
      gap: 24px;
      align-items: center;
      justify-content: center;
    }
    .price-card {
      flex: 1;
      min-width: 250px;
      padding: 36px 24px;
      text-align: center;
    }
    .price-card.featured {
      border: 2px solid var(--primary);
      box-shadow: 0 0 36px rgba(0,240,255,0.5);
      transform: scale(1.03);
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      margin-bottom: 12px;
      border-radius: 16px;
      overflow: hidden;
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      background: rgba(19,26,38,0.8);
    }
    .faq-answer {
      padding: 0 24px 20px;
      display: none;
      color: var(--text-body);
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    .faq-item.active {
      border-color: var(--border-glow);
    }
    /* footer */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    @media (max-width: 1024px) {
      .features-grid { grid-template-columns: repeat(2, 1fr); }
      .cases-grid { grid-template-columns: 1fr; }
    }
    @media (max-width: 768px) {
      .navbar .nav-links { display: none; }
      .mobile-nav { display: flex; }
      h1 { font-size: 36px; }
      .hero-grid { flex-direction: column; text-align: center; }
      .advantages-grid { flex-direction: column; align-items: center; }
      .adv-card:nth-child(n) { margin-top: 0; }
      .features-grid { grid-template-columns: 1fr; }
      .pricing-grid { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }