body{margin:0;font-family:Arial,sans-serif;background:#f2f2f2;color:#222}
.header{background:#222;color:#fff;padding:15px}
.header nav a{color:#fff;margin-right:12px;text-decoration:none}
.container{max-width:900px;margin:auto;padding:15px}
.card{background:#fff;padding:15px;margin-bottom:15px;border-radius:6px}
button{padding:8px 12px}
.footer{text-align:center;padding:10px;font-size:14px;color:#555}