CodePen

HTML

            
              <button id="one">Button one</button>
<button id="two">Button two</button>
            
          
!

CSS

            
              button {
  vertical-align: top;
  width: 10em;
  height: 2em;
  border: 0;
  transition: all 0.3s ease;
}
#one {
  background: #a7cd80;
}
#two {
  background: #8495a5;
}
            
          
!
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JS

            
              var current;
$('#one, #two').click(function() {
  if (current == null) {
    current = this;
    this.style.height = '10em';
  } else if (current == this) {
    this.style.height = '';
    current = null;
  }
});
            
          
!
Must be a valid URL.
+ add another resource
via JS Hint
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