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.{width: 50%;}
}