/* System font for performance and consistency */
    :root {
      --bg: #0b1220;         /* Dark background (water/professional theme) */
      --panel: #101a2f;      /* Card background */
      --text: #e6eefb;       /* Main text color */
      --muted: #b9c7e6;      /* Secondary text color */
      --accent: #5bb1ff;     /* Water blue accent */
      --accent-2: #3a8be0;
      --ring: rgba(91,177,255,0.35);
    }
    @media (prefers-color-scheme: light) {
      :root {
        --bg: #f5f7fb;
        --panel: #ffffff;
        --text: #0f172a;
        --muted: #475569;
        --accent: #0ea5e9;
        --accent-2: #0284c7;
        --ring: rgba(14,165,233,0.25);
      }
    }
    * { box-sizing: border-box; }
    html, body { height: 100%; }
    body {
      margin: 0;
      display: grid;
      place-items: center;
      /* Subtle water-themed gradient background */
      background: radial-gradient(1200px 700px at 70% 10%, rgba(91,177,255,0.15), transparent 60%) ,
                  radial-gradient(1000px 600px at 20% 90%, rgba(58,139,224,0.12), transparent 60%) ,
                  var(--bg);
      font-family: system-ui, -apple-system, Segoe UI, Roboto, "Helvetica Neue", Arial, sans-serif;
      color: var(--text);
    }
    .card {
      width: min(720px, 92vw);
      padding: 2rem 2.25rem;
      border-radius: 16px;
      background: linear-gradient(180deg, var(--panel), color-mix(in oklab, var(--panel), #000 4%));
      box-shadow:
        0 18px 40px -10px rgba(0,0,0,0.45),
        0 0 0 1px rgba(255,255,255,0.06);
      position: relative;
      overflow: hidden;
    }
    .header {
      display: flex;
      align-items: center;
      gap: 1rem;
      margin-bottom: 1rem;
    }
    .icon {
      width: 48px;
      height: 48px;
      flex: 0 0 48px;
      border-radius: 12px;
      /* Gradient icon background for maintenance theme */
      background:
        radial-gradient(12px 12px at 70% 30%, rgba(255,255,255,0.35), transparent 60%),
        linear-gradient(135deg, var(--accent), var(--accent-2));
      box-shadow: 0 8px 20px -6px var(--ring);
      display: grid;
      place-items: center;
    }
    h1 {
      font-size: clamp(1.25rem, 2.5vw, 1.5rem);
      line-height: 1.3;
      margin: 0;
    }
    .content {
      font-size: clamp(1rem, 1.8vw, 1.0625rem);
      line-height: 1.6;
      color: var(--muted);
    }
    .divider {
      height: 1px;
      margin: 1rem 0 1.25rem;
      background: linear-gradient(to right, transparent, rgba(255,255,255,0.14), transparent);
    }
    .footer {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: .75rem;
      flex-wrap: wrap;
      color: var(--muted);
      font-size: .95rem;
    }
    .subtle {
      opacity: .85;
    }
    /* Accessibility: visible focus if links/buttons are added later */
    :focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }