:root {
    --bg-color: #fdfdfd;
    --text-color: #2c3e50;
    --accent-color: #27ae60;
    --font-stack: system-ui, sans-serif;
}
body {
    font-family: var(--font-stack);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    margin: 0;
    padding: 1rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}
header, footer { padding: 1rem 0; }
nav a { margin-right: 1rem; color: var(--accent-color); text-decoration: none; display: inline-block; padding: 0.5rem; }
h1, h2 { color: #1a252f; }
form { margin: 2rem 0; }
input { padding: 0.75rem; border: 1px solid #ccc; width: 100%; max-width: 300px; margin-bottom: 1rem; display: block; }
button { padding: 0.75rem 1.5rem; background: var(--accent-color); color: white; border: none; cursor: pointer; }
@media (prefers-color-scheme: dark) {
    :root { --bg-color: #121212; --text-color: #e0e0e0; }
    h1, h2 { color: #ffffff; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; } }