body { font-family: Arial, sans-serif; margin:0; padding:0; background:#f5f5f5; }
header { background:#222; color:white; padding:15px; text-align:center; }
header h1 { margin:0; }
nav ul { list-style:none; padding:0; }
nav ul li { display:inline-block; margin:0 10px; }
nav ul li a { color:white; text-decoration:none; }
main { padding:20px; background:white; min-height:400px; }
footer { text-align:center; padding:15px; background:#ddd; }