/* roulang page: index */
/* ----- 设计变量与全局重置 ----- */
    :root {
      --bg-deep: #0A0F1E;
      --primary-cyan: #00E5FF;
      --accent-red: #FF4D6D;
      --text-white: #FFFFFF;
      --text-body: #B0C4DE;
      --text-muted: #6B7B8D;
      --glass-bg: rgba(10, 15, 30, 0.7);
      --glass-border: rgba(255, 255, 255, 0.06);
      --card-bg: rgba(255, 255, 255, 0.03);
      --shadow-cyan: 0 8px 32px rgba(0, 229, 255, 0.15);
      --radius-card: 16px;
      --radius-btn: 50px;
      --radius-img: 12px;
      --radius-data: 20px;
      --font-mono: 'Roboto Mono', 'DIN Alternate', 'Menlo', monospace;
      --transition-smooth: all 0.3s ease;
    }

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

    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background-color: var(--bg-deep);
      color: var(--text-body);
      line-height: 1.7;
      font-weight: 400;
      overflow-x: hidden;
      background-image: radial-gradient(circle at 30% 40%, rgba(0, 229, 255, 0.03) 0%, transparent 30%);
    }

    /* 自定义网格纹理叠加（CSS 实现） */
    body::before {
      content: "";
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: 
        linear-gradient(rgba(255, 255, 255, 0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
      background-size: 40px 40px;
      pointer-events: none;
      z-index: 0;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
      position: relative;
      z-index: 2;
    }

    h1, h2, h3, h4 {
      color: var(--text-white);
      font-weight: 700;
      letter-spacing: -0.02em;
      line-height: 1.3;
    }

    h1 {
      font-size: 3.4rem;
      margin-bottom: 1.5rem;
    }

    h2 {
      font-size: 2.5rem;
      margin-bottom: 0.75rem;
      text-align: center;
    }

    h3 {
      font-size: 1.5rem;
      margin-bottom: 0.5rem;
    }

    a {
      color: var(--primary-cyan);
      text-decoration: none;
      transition: var(--transition-smooth);
    }

    a:hover {
      color: #fff;
    }

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      outline: none;
      transition: var(--transition-smooth);
    }

    /* ----- 导航栏 (沉浸式/玻璃效果) ----- */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      padding: 1.2rem 0;
      transition: background 0.4s ease, backdrop-filter 0.4s ease, box-shadow 0.4s ease;
      background: transparent;
    }

    .site-header.scrolled {
      background: var(--glass-bg);
      backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(0, 229, 255, 0.2);
      box-shadow: 0 4px 20px rgba(0,0,0,0.5);
      padding: 0.8rem 0;
    }

    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--text-white);
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }
    .logo i {
      color: var(--primary-cyan);
      font-size: 2rem;
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 2rem;
      list-style: none;
    }

    .nav-menu a {
      color: var(--text-body);
      font-weight: 500;
      font-size: 1rem;
      position: relative;
    }

    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--primary-cyan);
    }

    .nav-cta {
      background: var(--primary-cyan);
      color: var(--bg-deep) !important;
      padding: 0.6rem 1.8rem;
      border-radius: var(--radius-btn);
      font-weight: 700;
      box-shadow: 0 0 12px rgba(0,229,255,0.4);
      margin-left: 0.5rem;
    }
    .nav-cta:hover {
      background: #33ebff;
      box-shadow: 0 0 22px rgba(0,229,255,0.7);
      color: #000 !important;
    }

    .hamburger {
      display: none;
      font-size: 1.8rem;
      color: var(--text-white);
      background: none;
      border: none;
    }

    /* 移动端导航 */
    @media (max-width: 768px) {
      .hamburger {
        display: block;
      }
      .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 75%;
        max-width: 320px;
        height: 100vh;
        background: rgba(10,15,30,0.95);
        backdrop-filter: blur(24px);
        flex-direction: column;
        justify-content: center;
        gap: 2.5rem;
        transition: right 0.4s ease;
        border-left: 1px solid rgba(0,229,255,0.2);
        padding: 2rem;
      }
      .nav-menu.active {
        right: 0;
      }
      .nav-cta {
        margin-left: 0;
      }
    }

    /* ----- 区块通用间距 ----- */
    section {
      padding: 5rem 0;
      position: relative;
      z-index: 2;
    }

    /* ----- Hero 首屏 ----- */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      padding-top: 5rem;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
    }
    .hero-left h1 {
      font-size: 3.8rem;
      line-height: 1.15;
    }
    .hero-left .subtitle {
      font-size: 1.2rem;
      color: var(--text-body);
      margin-bottom: 2.5rem;
      max-width: 450px;
    }
    .btn-group {
      display: flex;
      gap: 1.2rem;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary-cyan);
      color: #0A0F1E;
      padding: 0.9rem 2.5rem;
      border-radius: var(--radius-btn);
      font-weight: 700;
      font-size: 1rem;
      box-shadow: 0 0 18px rgba(0,229,255,0.5);
    }
    .btn-primary:hover {
      background: #33ebff;
      box-shadow: 0 0 28px rgba(0,229,255,0.8);
    }
    .btn-secondary {
      background: transparent;
      border: 1px solid var(--primary-cyan);
      color: var(--primary-cyan);
      padding: 0.9rem 2.5rem;
      border-radius: var(--radius-btn);
      font-weight: 700;
    }
    .btn-secondary:hover {
      background: rgba(0,229,255,0.1);
    }

    .hero-right {
      position: relative;
    }
    .glass-preview {
      background: rgba(10,15,30,0.6);
      backdrop-filter: blur(14px);
      border: 1px solid rgba(0,229,255,0.15);
      border-radius: 24px;
      padding: 1.5rem;
      transform: perspective(1000px) rotateY(-4deg) rotateX(2deg);
      box-shadow: 0 25px 40px -15px rgba(0,0,0,0.7);
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      background-blend-mode: overlay;
      min-height: 380px;
      display: flex;
      flex-direction: column;
      justify-content: flex-end;
    }
    .live-badge {
      background: var(--accent-red);
      color: white;
      padding: 0.25rem 1rem;
      border-radius: 20px;
      font-weight: 700;
      font-size: 0.8rem;
      display: inline-block;
      width: fit-content;
      margin-bottom: 0.8rem;
    }
    .data-stream {
      font-family: var(--font-mono);
      color: var(--primary-cyan);
      font-size: 1.2rem;
      text-shadow: 0 0 8px cyan;
    }

    /* ----- 功能卡片山形布局 ----- */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
      margin-top: 3rem;
    }
    .feature-card {
      background: var(--card-bg);
      backdrop-filter: blur(12px);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-card);
      padding: 2rem 1.8rem;
      transition: var(--transition-smooth);
      height: fit-content;
    }
    .feature-card:nth-child(2) {
      transform: translateY(-12px);
      border-color: rgba(0,229,255,0.2);
      box-shadow: 0 8px 28px rgba(0,229,255,0.1);
    }
    .feature-card:hover {
      box-shadow: var(--shadow-cyan);
      border-color: rgba(0,229,255,0.3);
    }
    .feature-icon {
      font-size: 2.2rem;
      color: var(--primary-cyan);
      margin-bottom: 1.5rem;
    }

    /* 场景交替 */
    .scenario-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
      margin-bottom: 4rem;
    }
    .scenario-img {
      border-radius: 20px 0 20px 0;
      overflow: hidden;
      background: rgba(0,229,255,0.05);
      position: relative;
    }
    .scenario-img img {
      width: 100%;
      height: auto;
      object-fit: cover;
      border-radius: inherit;
    }
    .scenario-content ul {
      list-style: none;
      margin-top: 1rem;
    }
    .scenario-content li {
      margin-bottom: 0.8rem;
      display: flex;
      align-items: center;
      gap: 0.6rem;
    }
    .scenario-content li i {
      color: var(--primary-cyan);
    }

    /* 案例数据看板 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 1.5rem;
      margin: 2.5rem 0;
    }
    .stat-card {
      background: rgba(255,255,255,0.02);
      backdrop-filter: blur(8px);
      border: 1px solid rgba(255,255,255,0.05);
      border-radius: var(--radius-data);
      padding: 2rem 1rem;
      text-align: center;
    }
    .stat-number {
      font-family: var(--font-mono);
      font-size: 2.6rem;
      color: var(--primary-cyan);
      text-shadow: 0 0 10px rgba(0,229,255,0.7);
    }
    .case-cards {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
      margin-top: 2rem;
    }
    .case-card {
      background: var(--glass-bg);
      backdrop-filter: blur(12px);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-card);
      padding: 1.5rem;
    }

    /* 价格卡片 */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
      margin-top: 2.5rem;
      align-items: start;
    }
    .price-card {
      background: var(--card-bg);
      backdrop-filter: blur(12px);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-card);
      padding: 2.2rem 1.8rem;
      position: relative;
    }
    .price-card.featured {
      border: 1px solid var(--primary-cyan);
      box-shadow: 0 0 30px rgba(0,229,255,0.25);
      transform: scale(1.02);
    }
    .badge-hot {
      background: var(--accent-red);
      color: white;
      padding: 0.2rem 1rem;
      border-radius: 20px;
      font-size: 0.8rem;
      position: absolute;
      top: -12px;
      right: 20px;
    }

    /* FAQ 手风琴 */
    .faq-item {
      background: rgba(255,255,255,0.02);
      backdrop-filter: blur(8px);
      border: 1px solid rgba(255,255,255,0.05);
      border-radius: 12px;
      margin-bottom: 1rem;
      overflow: hidden;
    }
    .faq-question {
      padding: 1.2rem 1.8rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      font-weight: 600;
      color: white;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      background: rgba(0,229,255,0.02);
    }
    .faq-answer p {
      padding: 0 1.8rem 1.2rem;
      color: var(--text-body);
    }

    /* 页脚 */
    .footer-cta {
      background: #060B14;
      text-align: center;
      padding: 4rem 1rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
      padding: 3rem 0;
    }

    @media (max-width: 1024px) {
      h1 { font-size: 2.8rem; }
      .hero-grid, .scenario-row { grid-template-columns: 1fr; }
      .features-grid { grid-template-columns: 1fr; }
      .feature-card:nth-child(2) { transform: none; }
      .stats-grid { grid-template-columns: repeat(2,1fr); }
      .pricing-grid, .case-cards { grid-template-columns: 1fr; }
    }
    @media (max-width: 768px) {
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }