html {
    font-size: 12pt; }
    
    @media (min-width:640px) {
        html {font-size: 16pt;}
    }

img { 
    max-width: 100%; 
}

body {
    margin-left: auto;
    margin-right: auto;
    width: 90%;
    max-width: 40rem;
}

 .two-columns-example {
    display: flex;
  }

  .two-columns-example > * {
    width: 50%;
  }