img {
     max-width: 100%; 
    }
body{
    margin-left: auto;
    margin-right:auto;
    width:90%;
    max-width: 40rem;
}
html { font-size: 12pt; }
  @media (min-width: 640px) {
    html { font-size: 16pt; }
  }

  @media (min-width: 640px) {
    .two-columns-example{
        display: flex;
      }
      .two-columns-example > *