body { font-family: Arial, sans-serif; margin:0; padding:0; }
header { background:#222; color:#fff; padding:20px; }
nav a { margin-right:15px; color:#fff; text-decoration:none; }
.container { padding:20px; max-width:900px; margin:auto; }
footer { background:#eee; padding:20px; text-align:center; margin-top:40px;}