/* roulang page: index */
:root {
      --primary: #4F46E5;
      --primary-dark: #4338CA;
      --accent-cyan: #06B6D4;
      --accent-orange: #F97316;
      --bg-light: #F8FAFC;
      --text-main: #0F172A;
      --text-sub: #64748B;
      --border-color: #E2E8F0;
    }
    body {
      font-family: system-ui, -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      color: var(--text-main);
      background-color: var(--bg-light);
      line-height: 1.75;
    }
    .custom-scroll {
      scroll-behavior: smooth;
    }
    .hero-bg {
      background-image: linear-gradient(135deg, rgba(15, 23, 42, 0.94) 0%, rgba(30, 27, 75, 0.92) 100%), url('/assets/images/16e901628a15286d.jpg');
      background-size: cover;
      background-position: center;
    }
    .stack-card-left {
      transform: rotate(-3deg) translateY(10px);
    }
    .stack-card-right {
      transform: rotate(3deg) translateY(20px);
    }
    .accordion-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease-out, padding 0.35s ease;
    }
    .accordion-item.active .accordion-content {
      max-height: 280px;
    }
    .accordion-item.active .accordion-icon {
      transform: rotate(180deg);
    }