:root {
    --bg-color: #fcfcfc;
    --text-color: #333;
    --link-color: #005a8c;
    --padding: 1.5rem;
}
@media (prefers-color-scheme: dark) {
    :root { --bg-color: #1a1a1a; --text-color: #eee; --link-color: #5db0d7; }
}
body { font-family: system-ui, sans-serif; background: var(--bg-color); color: var(--text-color); line-height: 1.6; margin: 0; padding: var(--padding); max-width: 800px; margin: auto; }
header, footer { padding: 1rem 0; }
a { color: var(--link-color); text-decoration: none; }
button { padding: 0.8rem 1.2rem; cursor: pointer; min-height: 44px; min-width: 44px; }
input { padding: 0.8rem; margin: 0.5rem 0; width: 100%; box-sizing: border-box; }
footer { border-top: 1px solid #ccc; margin-top: 2rem; font-size: 0.9rem; }