body {font-family: Arial, sans-serif;margin:0;padding:0;}
header {background:#4CAF50;color:white;padding:10px;text-align:center;}
.categories a, .menu-item {display:block;margin:5px;padding:5px;border:1px solid #ccc;text-decoration:none;color:black;}
button {padding:5px 10px;margin-top:5px;}
.dark-mode {background:#222;color:#eee;}