CSS onCLick

HTML

<button>
</button>

CSS

button {
    width: 140px;
    height: 70px;
    background: url('http://www.ranklogos.com/wp-content/uploads/2015/06/Stack-Overflow-Logo.png');
    background-size: cover;
  }
      
  button:focus {
    width: 240px;
    height: 120px;
  }