/* roulang page: index */
:root {
      --primary: #1e3a8a;
      --accent: #2563eb;
      --dark: #0f172a;
      --light-bg: #f8fafc;
      --card-border: #e2e8f0;
      --text-main: #334155;
      --text-muted: #64748b;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      background-color: var(--light-bg);
      color: var(--text-main);
      font-family: 'PingFang SC', 'Microsoft YaHei', -apple-system, sans-serif;
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
    }
    .hero-countdown-ring {
      background: conic-gradient(#2563eb 82%, #e2e8f0 0);
    }
    .custom-shadow {
      box-shadow: 0 4px 20px -2px rgba(15, 23, 42, 0.06), 0 2px 6px -1px rgba(15, 23, 42, 0.04);
    }
    .custom-shadow-hover {
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .custom-shadow-hover:hover {
      box-shadow: 0 20px 25px -5px rgba(15, 23, 42, 0.1), 0 10px 10px -5px rgba(15, 23, 42, 0.04);
      transform: translateY(-5px);
    }
    .tech-grid-bg {
      background-image: radial-gradient(rgba(255, 255, 255, 0.12) 1px, transparent 1px);
      background-size: 24px 24px;
    }
    .details-arrow {
      transition: transform 0.25s ease;
    }
    details[open] .details-arrow {
      transform: rotate(180deg);
    }