body { font-family: Arial, sans-serif; margin:0; padding:0; }
header, footer { background-color:#333; color:white; padding:10px; }
nav ul { list-style:none; padding:0; display:flex; }
nav li { margin-right:15px; }
nav a { color:white; text-decoration:none; }
aside { background-color:#f4f4f4; padding:10px; }
main { padding: 10px; }