/* roulang page: index */
:root {
      --primary: #0EA5E9;
      --primary-dark: #0284C7;
      --primary-cyan: #00F2FE;
      --accent-violet: #6366F1;
      --accent-lime: #10B981;
      --bg-dark: #090D16;
      --bg-slate: #0F172A;
      --bg-light: #F8FAFC;
      --border-color: rgba(226, 232, 240, 0.8);
      --text-main: #0F172A;
      --text-muted: #475569;
    }

    html {
      scroll-behavior: smooth;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    }

    body {
      background-color: #ffffff;
      color: var(--text-main);
      overflow-x: hidden;
    }

    /* 科技网格背景修饰 */
    .tech-grid-pattern {
      background-size: 30px 30px;
      background-image: 
        linear-gradient(to right, rgba(14, 165, 233, 0.05) 1px, transparent 1px),
        linear-gradient(to bottom, rgba(14, 165, 233, 0.05) 1px, transparent 1px);
    }
    .dark-tech-pattern {
      background-size: 40px 40px;
      background-image: 
        linear-gradient(to right, rgba(255, 255, 255, 0.04) 1px, transparent 1px),
        linear-gradient(to bottom, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
    }

    /* 竖屏视频质感框 */
    .vertical-screen-box {
      aspect-ratio: 9 / 16;
      box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.35), 0 0 25px rgba(14, 165, 233, 0.25);
    }

    /* 卡片微悬浮交互 */
    .tech-card {
      transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
      border: 1px solid var(--border-color);
    }
    .tech-card:hover {
      transform: translateY(-4px);
      box-shadow: 0 16px 30px -10px rgba(14, 165, 233, 0.15);
      border-color: rgba(14, 165, 233, 0.4);
    }

    /* 徽章微光 */
    .glow-badge {
      box-shadow: 0 0 12px rgba(14, 165, 233, 0.2);
    }

    /* 自定义手风琴动画 */
    .faq-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease-out;
    }
    .faq-item.active .faq-content {
      max-height: 240px;
    }
    .faq-item.active .faq-icon {
      transform: rotate(180deg);
    }