:root {
    --bg-color: #ffffff;
    --text-color: #2d3436;
    --link-color: #0984e3;
    --font-stack: system-ui, -apple-system, sans-serif;
}
body {
    font-family: var(--font-stack);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}
header, footer {
    padding: 20px 0;
    border-top: 1px solid #dfe6e9;
}
a { color: var(--link-color); }
nav a { margin-right: 15px; text-decoration: none; }
h1 { font-size: 2rem; }
input[type="email"] { padding: 10px; width: 250px; }
button { padding: 10px 20px; cursor: pointer; }
textarea { width: 100%; height: 100px; margin: 10px 0; }
@media (prefers-color-scheme: dark) {
    :root { --bg-color: #2d3436; --text-color: #dfe6e9; --link-color: #74b9ff; }
}
@media (prefers-reduced-motion: reduce) { * { animation: none !important; transition: none !important; } }