* {
  box-sizing: border-box;
  columns: 2 auto;
  columns: auto 12em;
  columns: auto auto;
}

body {
  font-family: Arial;
  padding: 20px;
  background: #f1f1f1;
}

h1 {
  padding: 30px;
  font-size: 40px;
  text-align: center;
  background: white;
}

.leftcolumn {
  float: left;
  width: 75%;
}

.rightcolumn {
  float: left;
  width: 25%;
  padding-left: 20px;
}

.card {
  background-color: white;
  padding: 20px;
  margin-top: 20px;
}

.row:after {
  content: "";
  display: table;
  clear: both;
}

.footer {
  padding: 20px;
  text-align: center;
  background: #ddd;
  margin-top: 20px;
}

@media screen and (max-width: 800px) {
  .leftcolumn, .rightcolumn {
    width: 100%;
    padding: 0;
  }
}