style.min.css

.footer,.header,.topnav a{text-align:center}.card,.footer{margin-top:20px}*{box-sizing:border-box;transition:.7s}body{font-family:Arial;padding:10px;background:#f1f1f1}.header{padding:30px;background:#fff}.header h1{font-size:50px}.topnav{overflow:hidden;background-color:#333}.topnav a{float:left;display:block;color:#f2f2f2;padding:14px 16px;text-decoration:none;transition:.3s}.card,.fakeimg,.footer{padding:20px}.topnav a:hover{background-color:#ddd;color:#000}.leftcolumn{float:left;width:75%}.rightcolumn{float:left;width:25%;background-color:#f1f1f1;padding-left:20px}.fakeimg{background-color:#aaa;width:100%}.card{background-color:#fff}.row:after{content:"";display:table;clear:both}.footer{background:#ddd}@media screen and (max-width:800px){.leftcolumn,.rightcolumn{width:100%;padding:0}}@media screen and (max-width:400px){.topnav a{float:none;width:100%}}