* {
    box-sizing: border-box;
}
body {
    padding: 20px;
    background: #f1f1f1;
}
.header {
    padding: 30px;
    font-size: 40px;
    text-align: center;
    background: yellow;
    background-image: url('icon\ image.PNG');
    background-position: center;
    background-size: cover;
  }
  .leftcolumn {   
    float: left;
    width: 75%;
  }
  .rightcolumn {
    float: left;
    width: 25%;
    padding-left: 20px;
  }
  @media screen and (max-width: 800px) {
    .leftcolumn, .rightcolumn {   
      width: 100%;
      padding: 0;
    }
  }
  .card {
    background-color: yellowgreen;
    padding: 20px;
    margin-top: 20px;
 }
 .row:after {
    content: "";
    display: table;
    clear: both;
  }
 .footer {
    padding: 20px;
    text-align: center;
    background: #ddd;
    margin-top: 20px;
  }
  table, th, td {
    border: 1px solid black;
  }