body { font-family: Arial, sans-serif; background:#1e1e1e; color:#f4f4f4; margin:0; }
nav { background:#222; padding:10px; }
nav a { color:#fff; text-decoration:none; margin:0 10px; font-weight:bold; }
nav a:hover { text-decoration:underline; }
header { background:#333; padding:20px; text-align:center; }
main { padding:20px; text-align:center; }
a.btn { display:inline-block; margin-top:15px; padding:10px 20px; background:teal; color:#fff; border-radius:4px; text-decoration:none; }
a.btn:hover { background:#009999; }
footer { margin:40px 0; text-align:center; color:#aaa; font-size:.9rem; }