anchor.diff:                  -ms-user-select: none;
                   -o-user-select: none;
               }
  +            #motor button {
  +                background-color: #1F3A93;
  +            }
  +            #led button {
  +                background-color: #CF000F;
  +            }
       body
           h1 R2-D2 Controller
  -        button#forward forward
  -        button#backward backward
  +        div#motor
  +            button#forward forward
  +            button#backward backward
  +        div#led
  +            button#on LED on
  +            button#off LED off
           script.
               var forwardButton = document.getElementById('forward');
               var backwardButton = document.getElementById('backward');
  +            var ledOnButton = document.getElementById('on');
  +            var ledOffButton = document.getElementById('off');
               
               function post(req) {
                   var xhr = new XMLHttpRequest();
  
positive.code:                 margin: 20px auto;
                  font-size: 1em;
                  color: white;
                  background-color: #1F3A93;
                  border-radius: 10px;
                  -webkit-appearance: none;
                  user-select: none;
  
negative.code:             forwardButton.addEventListener('mouseup', e => post('stop'));
              backwardButton.addEventListener('mousedown', e => post('backward'));
              backwardButton.addEventListener('mouseup', e => post('stop'));
              ledOnButton.addEventListener('mousedown', e => post('on'));
              ledOffButton.addEventListener('mousedown', e => post('off'));
  