:root { color-scheme: dark; }
* { box-sizing: border-box; }
body { font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
       background: #0f172a; color: #e2e8f0; margin: 0; padding: 2rem; line-height: 1.6; }
a { color: #38bdf8; text-decoration: none; }
a:hover { text-decoration: underline; }
.card { background: #1e293b; border-radius: 12px; padding: 1.5rem;
        margin: 1rem 0; box-shadow: 0 4px 18px rgba(0,0,0,.25); }
header, footer { text-align: center; }
header img { width: 96px; height: 96px; }
nav ul { list-style: none; padding: 0; display: flex; gap: 1.2rem;
         justify-content: center; flex-wrap: wrap; }
footer { margin-top: 2rem; opacity: .7; font-size: .9rem; }