/* roulang page: index */
/* ----- 设计变量与重置 ----- */
    :root {
      --primary-deep: #0A0E27;
      --secondary-deep: #141832;
      --accent-red: #FF4655;
      --accent-cyan: #00E5FF;
      --text-light: rgba(255,255,255,0.9);
      --text-muted: #B0B8C5;
      --text-dim: rgba(255,255,255,0.6);
      --border-subtle: rgba(255,255,255,0.08);
      --card-bg: rgba(255,255,255,0.03);
      --glass-bg: rgba(10,14,39,0.7);
      --shadow-card: 0 4px 24px rgba(0,0,0,0.4);
      --shadow-hover: 0 8px 40px rgba(255,70,85,0.15);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --font-zh: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      --font-en: "Inter", "Rajdhani", sans-serif;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    body {
      font-family: var(--font-zh);
      background: var(--primary-deep);
      color: var(--text-light);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      background-image: radial-gradient(circle at 30% 10%, rgba(0,229,255,0.08) 0%, transparent 45%);
    }
    
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }
    
    h1, h2, h3, h4 {
      font-family: var(--font-zh);
      font-weight: 700;
      letter-spacing: -0.02em;
    }
    
    h2 {
      font-size: 40px;
      line-height: 1.3;
      margin-bottom: 16px;
    }
    
    h3 {
      font-size: 24px;
      line-height: 1.4;
      font-weight: 600;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }
    
    img {
      max-width: 100%;
      display: block;
    }
    
    button, input, textarea {
      font-family: inherit;
    }
    
    /* ----- 导航栏：透明玻璃沉浸式 ----- */
    .main-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: var(--glass-bg);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid var(--border-subtle);
      transition: background 0.3s ease;
    }
    
    .main-header.scrolled {
      background: rgba(10,14,39,0.95);
    }
    
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    
    .logo {
      font-size: 28px;
      font-weight: 700;
      letter-spacing: 1px;
      color: white;
      display: flex;
      align-items: baseline;
      gap: 2px;
    }
    .logo .cyan-dot {
      color: var(--accent-cyan);
      font-size: 34px;
      line-height: 1;
    }
    
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    
    .nav-links a {
      color: rgba(255,255,255,0.7);
      font-weight: 500;
      font-size: 15px;
      position: relative;
    }
    
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent-cyan);
    }
    
    .nav-cta {
      background: var(--accent-red);
      color: white !important;
      padding: 10px 24px;
      border-radius: 4px;
      font-weight: 600;
      letter-spacing: 0.5px;
      box-shadow: 0 0 15px rgba(255,70,85,0.3);
      transition: background 0.2s, box-shadow 0.2s;
    }
    .nav-cta:hover {
      background: #FF5E6B;
      box-shadow: 0 0 25px rgba(255,70,85,0.5);
    }
    
    .hamburger {
      display: none;
      font-size: 24px;
      color: white;
      cursor: pointer;
    }
    
    /* ----- Hero 首屏 ----- */
    .hero-section {
      padding: 160px 0 100px;
      display: flex;
      align-items: center;
      gap: 60px;
      position: relative;
    }
    .hero-left {
      flex: 1;
    }
    .hero-right {
      flex: 1;
      position: relative;
    }
    .hero-right img {
      border-radius: var(--radius-lg);
      border: 1px solid rgba(255,70,85,0.2);
      box-shadow: 0 0 60px rgba(255,70,85,0.15);
      transform: perspective(800px) rotateY(-3deg);
      background: #0f132a;
    }
    .hero-title {
      font-size: 56px;
      line-height: 1.2;
      background: linear-gradient(to right, #fff, #00E5FF);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      margin-bottom: 24px;
    }
    .hero-sub {
      font-size: 18px;
      color: var(--text-muted);
      margin-bottom: 40px;
      max-width: 480px;
    }
    .btn-group {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-red);
      color: white;
      padding: 14px 36px;
      border-radius: 4px;
      font-weight: 600;
      letter-spacing: 0.5px;
      border: none;
      cursor: pointer;
      transition: 0.2s;
      box-shadow: 0 0 15px rgba(255,70,85,0.3);
    }
    .btn-primary:hover {
      background: #FF5E6B;
      box-shadow: 0 0 30px rgba(255,70,85,0.5);
    }
    .btn-secondary {
      background: transparent;
      border: 1px solid var(--accent-red);
      color: var(--accent-red);
      padding: 14px 36px;
      border-radius: 4px;
      font-weight: 600;
      cursor: pointer;
      transition: 0.2s;
    }
    .btn-secondary:hover {
      background: rgba(255,70,85,0.1);
    }
    
    /* ----- 区块通用 ----- */
    .section {
      padding: 90px 0;
    }
    .section-header {
      text-align: center;
      margin-bottom: 60px;
    }
    .section-header h2 {
      color: white;
    }
    .section-header p {
      color: var(--text-muted);
      max-width: 600px;
      margin: 0 auto;
    }
    
    /* 亮点网格 不规则2x3 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-card {
      background: var(--card-bg);
      backdrop-filter: blur(10px);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-md);
      padding: 32px 24px;
      transition: all 0.25s;
    }
    .feature-card:hover {
      border-color: var(--accent-red);
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .feature-icon {
      font-size: 32px;
      color: var(--accent-cyan);
      margin-bottom: 20px;
    }
    .feature-card h3 {
      margin-bottom: 12px;
    }
    .feature-card p {
      color: var(--text-dim);
      font-size: 15px;
    }
    /* 错落调整 */
    .features-grid > :nth-child(4) {
      grid-column: span 2;
    }
    
    /* 产品展示瀑布流 */
    .products-flow {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 30px;
    }
    .product-item {
      background: rgba(20,24,50,0.7);
      border-radius: var(--radius-lg);
      overflow: hidden;
      border: 1px solid var(--border-subtle);
      transition: 0.2s;
    }
    .product-item:hover {
      border-color: var(--accent-cyan);
    }
    .product-item img {
      height: 200px;
      width: 100%;
      object-fit: cover;
    }
    .product-info {
      padding: 24px;
    }
    .product-info h3 {
      margin-bottom: 8px;
    }
    .text-link {
      color: var(--accent-cyan);
      font-weight: 600;
      display: inline-block;
      margin-top: 12px;
    }
    
    /* 案例数据卡片 */
    .cases-grid {
      display: flex;
      gap: 30px;
      flex-wrap: wrap;
    }
    .case-stat {
      flex: 1 1 200px;
      background: rgba(255,255,255,0.02);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-md);
      padding: 32px 20px;
      text-align: center;
    }
    .stat-number {
      font-family: 'Rajdhani', sans-serif;
      font-size: 52px;
      font-weight: 700;
      color: var(--accent-cyan);
    }
    
    /* 对比表 */
    .compare-table {
      display: flex;
      gap: 30px;
    }
    .compare-col {
      flex:1;
      background: #F0F2F5;
      color: #1a1a1a;
      border-radius: var(--radius-md);
      padding: 32px;
    }
    .compare-col.highlight {
      background: var(--secondary-deep);
      color: white;
      border: 1px solid var(--accent-red);
    }
    
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-subtle);
    }
    .faq-question {
      background: rgba(255,255,255,0.03);
      padding: 20px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    
    /* 联系表单 */
    .contact-box {
      background: #0f132a;
      border-radius: var(--radius-lg);
      padding: 48px;
      max-width: 680px;
      margin: 0 auto;
    }
    .form-input {
      width: 100%;
      background: rgba(255,255,255,0.05);
      border: 1px solid rgba(255,255,255,0.1);
      padding: 14px;
      margin-bottom: 20px;
      color: white;
      border-radius: 4px;
    }
    
    /* 页脚 */
    .footer {
      background: #080b1a;
      padding: 40px 0;
      border-top: 1px solid var(--border-subtle);
      text-align: center;
      color: var(--text-muted);
    }
    
    @media (max-width: 1024px) {
      .hero-section { flex-direction: column; }
      .features-grid { grid-template-columns: repeat(2,1fr); }
      .features-grid > :nth-child(4) { grid-column: span 1; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: block; }
      .hero-title { font-size: 36px; }
      .products-flow, .features-grid { grid-template-columns: 1fr; }
    }