body {
        margin: 0;
      }
      header {
        background: green;
        height: 100px;
      }
      h1 {
        text-align: center;
        color: white;
        line-height: 100px;
        margin: 0;
      }
      article {
        padding: 10px;
        margin: 10px;
        background: blue;
      }
 


section {display: flex; flex-wrap: wrap; justify-content: space-around; padding: 10 px; margin: 60 -5px; }