/* roulang page: index */
:root {
      --color-primary: #1D4ED8;
      --color-pulse: #06B6D4;
      --color-amber: #D97706;
      --color-slate-dark: #0B0F19;
      --color-bg-base: #F8FAFC;
      --color-text-main: #0F172A;
      --color-text-body: #334155;
      --color-text-muted: #64748B;
      --border-light: #E2E8F0;
      --radius-box: 1rem;
      --shadow-subtle: 0 10px 30px -10px rgba(15, 23, 42, 0.08);
      --shadow-hover: 0 20px 40px -15px rgba(29, 78, 216, 0.16);
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", sans-serif;
      color: var(--color-text-body);
      background-color: var(--color-bg-base);
      line-height: 1.8;
      overflow-x: hidden;
      -webkit-font-smoothing: antialiased;
    }
    .font-mono-num {
      font-family: Inter, "Roboto Mono", monospace;
    }
    .nav-link {
      position: relative;
      transition: color 0.2s ease;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      width: 0;
      height: 2px;
      bottom: -4px;
      left: 0;
      background-color: var(--color-primary);
      transition: width 0.25s ease;
    }
    .nav-link:hover::after {
      width: 100%;
    }
    .radar-dot-bg {
      background-image: radial-gradient(rgba(29, 78, 216, 0.08) 1px, transparent 1px);
      background-size: 24px 24px;
    }
    .radar-sweep {
      position: relative;
      overflow: hidden;
    }
    .radar-sweep::before {
      content: '';
      position: absolute;
      inset: -50%;
      background: conic-gradient(from 0deg, transparent 0deg, rgba(6, 182, 212, 0.12) 60deg, transparent 65deg);
      animation: sweep 8s linear infinite;
      pointer-events: none;
    }
    @keyframes sweep {
      0% { transform: rotate(0deg); }
      100% { transform: rotate(360deg); }
    }
    .card-hardware {
      background: #FFFFFF;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-box);
      box-shadow: var(--shadow-subtle);
      transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    }
    .card-hardware:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-color: rgba(29, 78, 216, 0.35);
    }
    .btn-hardware {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 600;
      padding: 0.75rem 1.75rem;
      border-radius: 9999px;
      transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
      cursor: pointer;
    }
    .btn-hardware:hover {
      transform: translateY(-2px);
      box-shadow: 0 10px 20px -5px rgba(6, 182, 212, 0.3);
    }
    .accordion-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease-out;
    }
    .accordion-open .accordion-content {
      max-height: 480px;
    }
    .accordion-open .accordion-chevron {
      transform: rotate(180deg);
    }