body{font-family:Arial;margin:0;background:#f5f5f5;}
header{background:#003366;color:#fff;padding:20px;}
nav a{color:white;margin-right:15px;text-decoration:none;font-weight:bold;}
main{padding:20px;}
footer{background:#222;color:#ccc;padding:20px;text-align:center;margin-top:40px;}
.listing{background:white;padding:20px;margin:10px 0;border-radius:8px;}