Blob Checkbox

Prototyping

HTML

<div id="blobCheck" class="blobContainer">
  <div class="blob"></div>
</div>

CSS

@-webkit-keyframes blobCheckAnim {
  0% {
    left: 0;
  }
  33% {
    border-bottom-right-radius: 25% 50%;
    border-top-right-radius: 25% 50%;
    border-bottom-left-radius: 50%;
    border-top-left-radius: 50%;
    width: 120px;
    height: 40px;
    left: 0;
    top: 10px;
  }
  100% {
    left: 60px;
  }
}

@-webkit-keyframes blobUncheckAnim {
  0% {
    left: 60px;
  }
  33% {
    border-bottom-left-radius: 25% 50%;
    border-top-left-radius: 25% 50%;
    border-bottom-right-radius: 50%;
    border-top-right-radius: 50%;
    width: 120px;
    height: 40px;
    left: 0px;
    top: 10px;
  }
  100% {
    left: 0px;
  }
}

.blobContainer {
  width: 122px;
  height: 62px;
  padding: 5px;
  background: #666;
  border: 3px solid #999;
  border-radius: 41px;
  -webkit-box-shadow: inset 5px 5px 20px 0px rgba(00, 0, 0, .25);
  box-shadow: inset 5px 5px 20px 0px rgba(00, 0, 0, .25);
}

.blob {
  width: 60px;
  height: 60px;
  background: #B2FF71;
  border: 1px solid #B2FF71;
  border-radius: 50%;
  position: relative;
  left: 0;
  top: 0;
  -webkit-animation: blobUncheckAnim .25s ease-out;
  -webkit-box-shadow: inset 0px 0px 20px 0px rgba(00, 0, 0, .25);
  box-shadow: inset 0px 0px 20px 0px rgba(00, 0, 0, .25);
}

.blobContainer.checked .blob {
  -webkit-animation: blobCheckAnim .25s ease-out;
  left: 60px;
}

JavaScript

var blobCheck = document.getElementById('blobCheck');

blobCheck.onclick = function() {
  checkedTest = /\s?checked/ig;

  if (checkedTest.test(blobCheck.className)) {
    blobCheck.className = blobCheck.className.replace(checkedTest, '');
  } else {
    blobCheck.className += " checked";
  }
}