/* roulang page: index */
:root {
      --bg-dark: #0B0F17;
      --bg-slate: #0F172A;
      --bg-light: #F8FAFC;
      --text-main: #0F172A;
      --text-muted: #475569;
      --border-dark: rgba(255, 255, 255, 0.08);
      --border-light: #E2E8F0;
      --accent: #10B981;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.75;
      letter-spacing: 0.015em;
    }
    .code-terminal {
      background: #090D14;
      border: 1px solid rgba(255, 255, 255, 0.1);
      box-shadow: 0 20px 40px -15px rgba(0,0,0,0.6);
    }
    .gradient-glow {
      background: radial-gradient(circle at 50% 0%, rgba(16, 185, 129, 0.15), transparent 70%);
    }
    .custom-scroll::-webkit-scrollbar {
      height: 6px;
      width: 6px;
    }
    .custom-scroll::-webkit-scrollbar-thumb {
      background: #334155;
      border-radius: 3px;
    }
    .accordion-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s cubic-bezier(0.16, 1, 0.3, 1), padding 0.3s ease;
    }
    .accordion-item.active .accordion-content {
      max-height: 280px;
    }
    .accordion-item.active .accordion-icon {
      transform: rotate(180deg);
    }