/* roulang page: index */
/* ----- 全局变量与重置 ----- */
    :root {
      --primary: #0A84FF;
      --accent: #00F0FF;
      --deep-purple: #6C3CE1;
      --bg-dark: #0A0E17;
      --bg-section: #0D1322;
      --bg-card: #131C2E;
      --glass-bg: rgba(255, 255, 255, 0.03);
      --glass-border: rgba(255, 255, 255, 0.08);
      --text-primary: #FFFFFF;
      --text-body: #B0C4DE;
      --text-muted: #6B7D95;
      --border-light: rgba(255, 255, 255, 0.15);
      --radius-md: 12px;
      --radius-lg: 16px;
      --radius-xl: 50px;
      --shadow-glow: 0 0 20px rgba(0, 240, 255, 0.4);
      --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.4);
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
      --font-number: 'Inter', 'SF Pro Display', sans-serif;
      --max-width: 1280px;
      --header-height: 72px;
      --transition: 0.3s ease;
    }

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

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

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

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

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

    ul {
      list-style: none;
    }

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

    /* 容器 */
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }

    /* 区块通用 */
    section {
      padding: 100px 0;
    }

    @media (max-width: 768px) {
      section {
        padding: 80px 0;
      }
    }

    /* 标题装饰线 */
    .section-title {
      font-size: 36px;
      font-weight: 700;
      color: var(--text-primary);
      margin-bottom: 16px;
      display: flex;
      align-items: center;
      gap: 16px;
    }
    .section-title::before {
      content: '';
      display: inline-block;
      width: 40px;
      height: 4px;
      background: var(--accent);
      border-radius: 2px;
      box-shadow: 0 0 12px var(--accent);
    }

    @media (max-width: 768px) {
      .section-title {
        font-size: 28px;
      }
    }

    /* ----- 导航栏（固定玻璃拟态） ----- */
    header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--header-height);
      background: rgba(10, 14, 23, 0.85);
      backdrop-filter: blur(24px);
      -webkit-backdrop-filter: blur(24px);
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
      z-index: 1000;
      display: flex;
      align-items: center;
    }

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

    .logo-area {
      display: flex;
      align-items: center;
      gap: 12px;
    }

    .logo-text {
      font-size: 24px;
      font-weight: 700;
      color: var(--text-primary);
      letter-spacing: -0.5px;
      background: linear-gradient(135deg, var(--accent), var(--primary));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .logo-icon-nav {
      display: flex;
      gap: 8px;
      margin-left: 12px;
    }
    .logo-icon-nav i {
      font-size: 18px;
      color: var(--text-muted);
      transition: color 0.2s;
    }
    .logo-icon-nav i:hover {
      color: var(--accent);
    }

    .nav-links {
      display: flex;
      gap: 28px;
      align-items: center;
    }

    .nav-links a {
      font-size: 14px;
      font-weight: 500;
      color: var(--text-body);
      position: relative;
      padding: 8px 0;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--accent);
      transition: width 0.3s;
      border-radius: 2px;
    }
    .nav-links a:hover {
      color: var(--accent);
    }
    .nav-links a:hover::after {
      width: 100%;
    }

    .nav-actions {
      display: flex;
      align-items: center;
      gap: 16px;
    }

    .search-icon {
      color: var(--text-body);
      font-size: 18px;
      transition: color 0.2s;
    }
    .search-icon:hover {
      color: var(--accent);
    }

    .btn-ghost {
      background: transparent;
      border: 1px solid var(--border-light);
      color: var(--text-primary);
      padding: 8px 20px;
      border-radius: var(--radius-xl);
      font-weight: 600;
      font-size: 14px;
    }
    .btn-ghost:hover {
      border-color: var(--accent);
      background: rgba(0, 240, 255, 0.08);
    }

    .btn-primary-glow {
      background: linear-gradient(135deg, var(--accent), var(--primary));
      color: #000;
      font-weight: 700;
      padding: 10px 24px;
      border-radius: var(--radius-xl);
      box-shadow: 0 0 20px rgba(0, 240, 255, 0.5);
      font-size: 14px;
    }
    .btn-primary-glow:hover {
      box-shadow: 0 0 30px rgba(0, 240, 255, 0.8);
      transform: scale(1.05);
    }

    /* 移动端导航汉堡菜单 */
    #menu-toggle {
      display: none;
      background: none;
      border: none;
      color: var(--text-primary);
      font-size: 24px;
    }

    @media (max-width: 1024px) {
      .nav-links {
        gap: 16px;
      }
    }

    @media (max-width: 768px) {
      #menu-toggle {
        display: block;
      }
      .nav-links {
        position: absolute;
        top: var(--header-height);
        left: 0;
        width: 100%;
        background: rgba(10, 14, 23, 0.95);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 24px;
        gap: 20px;
        display: none;
        border-bottom: 1px solid rgba(255,255,255,0.1);
      }
      .nav-links.active {
        display: flex;
      }
      .nav-actions {
        gap: 12px;
      }
      .btn-primary-glow {
        padding: 8px 16px;
      }
    }

    /* ----- 首屏 Hero ----- */
    .hero {
      padding-top: calc(var(--header-height) + 40px);
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 30% 50%, #0F172A, #0A0E17);
      min-height: 90vh;
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 60% 40%;
      gap: 40px;
      align-items: center;
    }

    .hero-left h1 {
      font-size: 52px;
      font-weight: 800;
      line-height: 1.2;
      color: var(--text-primary);
      margin-bottom: 20px;
    }
    .highlight {
      background: linear-gradient(135deg, var(--accent), var(--primary));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .hero-sub {
      font-size: 18px;
      color: var(--text-body);
      margin-bottom: 32px;
      max-width: 480px;
    }

    .hero-metrics {
      display: flex;
      gap: 32px;
      margin-bottom: 32px;
    }
    .metric strong {
      font-family: var(--font-number);
      font-size: 28px;
      color: var(--accent);
      display: block;
    }
    .metric span {
      font-size: 14px;
      color: var(--text-muted);
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .hero-right {
      position: relative;
      display: flex;
      justify-content: center;
    }
    .hero-img-wrapper {
      width: 100%;
      border-radius: 24px;
      overflow: hidden;
      border: 1px solid rgba(0,240,255,0.2);
      box-shadow: 0 0 40px rgba(0,132,255,0.3);
      transform: perspective(800px) rotateY(-2deg);
      background: rgba(255,255,255,0.02);
    }
    .hero-img-wrapper img {
      width: 100%;
      height: auto;
      display: block;
      mix-blend-mode: lighten;
    }

    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
      }
      .hero-left h1 {
        font-size: 36px;
      }
      .hero-metrics {
        justify-content: center;
      }
      .hero-buttons {
        justify-content: center;
      }
      .hero-right {
        order: -1;
        margin-bottom: 24px;
      }
    }

    /* ----- 亮点网格（不对称3x2） ----- */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
      margin-top: 48px;
    }
    .feature-card {
      background: var(--glass-bg);
      backdrop-filter: blur(20px);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-lg);
      padding: 32px 24px;
      transition: all 0.3s ease;
    }
    .feature-card:hover {
      border-color: rgba(0,240,255,0.4);
      transform: translateY(-6px);
      box-shadow: 0 12px 30px rgba(0,240,255,0.15);
    }
    .feature-icon {
      font-size: 36px;
      color: var(--accent);
      filter: drop-shadow(0 0 8px rgba(0,240,255,0.5));
      margin-bottom: 16px;
    }
    .feature-card h3 {
      font-size: 20px;
      color: #fff;
      margin-bottom: 8px;
    }
    .feature-card p {
      font-size: 14px;
      color: var(--text-body);
    }

    /* 第二行偏移两个卡片 */
    .features-row-two {
      display: flex;
      justify-content: center;
      gap: 28px;
      margin-top: 28px;
    }
    .features-row-two .feature-card {
      width: calc(33.333% - 28px);
      max-width: 360px;
    }

    @media (max-width: 768px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
      .features-row-two {
        flex-direction: column;
        align-items: center;
      }
      .features-row-two .feature-card {
        width: 100%;
      }
    }

    /* ----- 案例瀑布流 (masonry 风格) ----- */
    .masonry-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 40px;
    }
    .masonry-item {
      border-radius: var(--radius-lg);
      overflow: hidden;
      background: var(--bg-card);
      border: 1px solid rgba(255,255,255,0.05);
      transition: all 0.3s;
    }
    .masonry-item:hover {
      border-color: var(--accent);
      box-shadow: 0 8px 28px rgba(0,240,255,0.25);
    }
    .masonry-img {
      position: relative;
      overflow: hidden;
      height: 220px;
    }
    .masonry-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.4s;
    }
    .masonry-item:hover .masonry-img img {
      transform: scale(1.05);
    }
    .masonry-info {
      padding: 16px;
      background: rgba(0,0,0,0.4);
    }
    .masonry-info h4 {
      color: #fff;
      font-size: 18px;
    }
    .masonry-info span {
      font-size: 13px;
      color: var(--accent);
    }
    @media (max-width: 768px) {
      .masonry-grid {
        grid-template-columns: 1fr;
      }
    }

    /* ----- 方案对比卡片 ----- */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
      margin-top: 40px;
    }
    .plan-card {
      background: var(--bg-card);
      border-radius: var(--radius-lg);
      padding: 32px 24px;
      border: 1px solid transparent;
      transition: all 0.3s;
    }
    .plan-card.popular {
      border-color: var(--accent);
      box-shadow: 0 0 20px rgba(0,240,255,0.2);
    }
    .plan-header {
      font-size: 22px;
      color: #fff;
      margin-bottom: 16px;
    }
    .plan-features li {
      margin: 12px 0;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    @media (max-width: 768px) {
      .pricing-grid {
        grid-template-columns: 1fr;
      }
    }

    /* FAQ 手风琴 */
    .faq-list {
      margin-top: 32px;
    }
    details {
      border-bottom: 1px solid rgba(255,255,255,0.08);
      padding: 20px 0;
    }
    summary {
      font-weight: 600;
      color: #fff;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
    }
    .faq-answer {
      color: var(--text-body);
      margin-top: 12px;
    }

    /* CTA 横幅 */
    .cta-banner {
      background: linear-gradient(135deg, #0F172A, #0A0E17);
      position: relative;
      text-align: center;
    }
    .cta-banner h2 {
      font-size: 40px;
      color: #fff;
    }

    /* 页脚 */
    footer {
      background: #080C14;
      padding: 60px 0 30px;
      border-top: 1px solid rgba(255,255,255,0.05);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }