body{font-family:sans-serif;margin:0;padding:0;background:#f7f7f7;}
header,footer{background:#222;color:#fff;padding:20px;}
main{max-width:1000px;margin:20px auto;background:#fff;padding:20px;}
nav a{margin-right:15px;color:#fff;text-decoration:none;}
.article-card{border-bottom:1px solid #ddd;padding:15px 0;}