/* roulang page: index */
/* ----- 设计令牌与基础重置 ----- */
    :root {
      --primary: #FF4655;
      --primary-gradient: linear-gradient(135deg, #FF4655 0%, #FF6B7A 100%);
      --deep-space: #0F1923;
      --deep-space-light: #1A2433;
      --victory-gold: #FFD700;
      --bg-light: #F8FAFC;
      --text-heading: #0B1219;
      --text-body: #334155;
      --text-on-dark: #FFFFFF;
      --text-on-dark-muted: #CBD5E1;
      --border-light: rgba(15, 25, 35, 0.06);
      --border-dark: rgba(255, 255, 255, 0.08);
      --card-shadow: 0 20px 35px -10px rgba(15, 25, 35, 0.08);
      --card-hover-shadow: 0 30px 45px -12px rgba(15, 25, 35, 0.12);
      --radius-card: 16px;
      --radius-btn: 8px;
      --radius-badge: 20px;
      --font-main: 'Inter', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      --font-mono: 'Rajdhani', 'Inter', monospace;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    html {
      scroll-behavior: smooth;
    }
    
    body {
      font-family: var(--font-main);
      background-color: var(--bg-light);
      color: var(--text-body);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
    }
    
    img {
      display: block;
      max-width: 100%;
      height: auto;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: opacity 0.2s;
    }
    
    button, input {
      font-family: inherit;
    }
    
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }
    
    /* 沉浸式导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      background: rgba(15, 25, 35, 0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-dark);
    }
    
    .navbar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 16px 0;
    }
    
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 800;
      font-size: 1.7rem;
      letter-spacing: 1px;
      color: white;
    }
    .logo-icon {
      font-size: 2rem;
      color: var(--primary);
      filter: drop-shadow(0 0 6px rgba(255,70,85,0.4));
    }
    .logo span {
      background: linear-gradient(to right, #fff, #ddd);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-link {
      font-weight: 500;
      color: var(--text-on-dark-muted);
      text-transform: uppercase;
      font-size: 0.85rem;
      letter-spacing: 1px;
      padding: 4px 0;
      border-bottom: 2px solid transparent;
      transition: 0.2s;
    }
    .nav-link:hover, .nav-link.active {
      color: white;
      border-bottom-color: var(--primary);
    }
    
    .hamburger {
      display: none;
      background: none;
      border: none;
      color: white;
      font-size: 1.8rem;
      cursor: pointer;
    }
    
    @media (max-width: 768px) {
      .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 75%;
        max-width: 300px;
        height: 100vh;
        background: var(--deep-space);
        flex-direction: column;
        padding: 100px 32px 32px;
        gap: 28px;
        transition: 0.35s ease;
        box-shadow: -10px 0 25px rgba(0,0,0,0.3);
        z-index: 99;
      }
      .nav-menu.active {
        right: 0;
      }
      .hamburger {
        display: block;
        z-index: 101;
      }
    }
    
    /* Hero首屏 */
    .hero {
      padding: 140px 0 80px;
      display: flex;
      align-items: center;
      gap: 48px;
    }
    .hero-left {
      flex: 1;
    }
    .hero-badge {
      display: inline-flex;
      align-items: center;
      background: rgba(255,70,85,0.1);
      backdrop-filter: blur(4px);
      border: 1px solid rgba(255,70,85,0.25);
      border-radius: 30px;
      padding: 6px 18px;
      font-size: 0.9rem;
      font-weight: 600;
      color: var(--primary);
      margin-bottom: 18px;
      gap: 8px;
    }
    .live-dot {
      width: 10px;
      height: 10px;
      background: #10B981;
      border-radius: 50%;
      box-shadow: 0 0 0 2px rgba(16,185,129,0.3);
      animation: pulse-dot 1.6s infinite;
    }
    @keyframes pulse-dot { 0%{box-shadow:0 0 0 0 rgba(16,185,129,0.4)} 70%{box-shadow:0 0 0 12px rgba(16,185,129,0)} 100%{box-shadow:0 0 0 0 rgba(16,185,129,0)} }
    
    .hero h1 {
      font-size: clamp(2.8rem, 7vw, 4rem);
      font-weight: 800;
      color: var(--text-heading);
      line-height: 1.2;
      margin-bottom: 18px;
    }
    .hero-highlight {
      color: var(--primary);
    }
    .hero-desc {
      font-size: 1.15rem;
      color: var(--text-body);
      margin-bottom: 28px;
      max-width: 480px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn {
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 8px;
      transition: all 0.2s;
      cursor: pointer;
      border: none;
    }
    .btn-primary {
      background: var(--primary-gradient);
      color: white;
      box-shadow: 0 8px 18px rgba(255,70,85,0.35);
    }
    .btn-primary:hover {
      transform: translateY(-2px);
      filter: brightness(1.08);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--text-heading);
      color: var(--text-heading);
    }
    .btn-outline:hover {
      background: var(--text-heading);
      color: white;
    }
    
    .hero-right {
      flex: 1;
      position: relative;
    }
    .hero-img-wrapper img {
      border-radius: 24px;
      box-shadow: 0 25px 45px -12px rgba(15,25,35,0.25);
      transform: perspective(800px) rotateY(-4deg);
      transition: 0.3s;
    }
    
    @media (max-width: 768px) {
      .hero {
        flex-direction: column;
        padding: 120px 0 50px;
      }
      .hero-right img {
        transform: none;
      }
    }
    
    /* 数据看板卡片 */
    .data-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
      gap: 20px;
      margin-top: -20px;
    }
    .data-card {
      background: var(--deep-space-light);
      backdrop-filter: blur(8px);
      border-radius: var(--radius-card);
      padding: 22px;
      color: white;
      border: 1px solid var(--border-dark);
      display: flex;
      flex-direction: column;
      gap: 6px;
    }
    .data-label {
      font-size: 0.9rem;
      color: var(--text-on-dark-muted);
    }
    .data-value {
      font-family: var(--font-mono);
      font-size: 2.3rem;
      font-weight: 700;
      letter-spacing: 1px;
    }
    .trend-up {
      color: #10B981;
      font-weight: 600;
    }
    
    /* 公用区块标题 */
    .section {
      padding: 70px 0;
    }
    .section-title {
      font-size: 2.3rem;
      font-weight: 700;
      color: var(--text-heading);
      text-align: center;
      margin-bottom: 12px;
    }
    .section-sub {
      text-align: center;
      color: var(--text-body);
      margin-bottom: 48px;
    }
    
    /* 服务卡片错落网格 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .service-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 32px 24px;
      border: 1px solid var(--border-light);
      transition: all 0.25s;
      border-top: 4px solid var(--primary);
      box-shadow: var(--card-shadow);
    }
    .service-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--card-hover-shadow);
      border-top-color: var(--victory-gold);
    }
    .service-icon {
      font-size: 2.5rem;
      color: var(--primary);
      margin-bottom: 18px;
    }
    
    @media (max-width: 1024px) {
      .services-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 640px) {
      .services-grid {
        grid-template-columns: 1fr;
      }
    }
    
    /* 流程三步 */
    .steps {
      display: flex;
      justify-content: space-between;
    }
    .step-item {
      text-align: center;
      flex:1;
    }
    
    /* FAQ */
    .faq-item {
      background: white;
      border: 1px solid var(--border-light);
      border-radius: 12px;
      margin-bottom: 14px;
      overflow: hidden;
    }
    .faq-question {
      padding: 14px 20px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    
    /* CTA深色区域 */
    .cta-dark {
      background: var(--deep-space);
      border-radius: var(--radius-card);
      padding: 60px 45px;
    }
    .input-field {
      background: rgba(255,255,255,0.08);
      border: 1px solid rgba(255,255,255,0.2);
      border-radius: 6px;
      padding: 12px 16px;
      color: white;
    }
    
    .footer {
      background: var(--deep-space);
      color: var(--text-on-dark-muted);
      padding: 48px 0 24px;
    }