[CSS 3] Create Custom Keyboard Accessible Checkboxes

Take the native HTML checkboxes and jazz them up while still ensuring they are keyboard accessible. We use pseudo-elements and pseudo-classes to replicate the focus and the ability to tab to custom checkboxes. 

/* hide native one */
input[type="checkbox"] + label {
  display: block;
  position: relative;
  padding-left: 2rem;
}

/* create a checkbox */
input[type="checkbox"] + label::before {
  content: '';
  position: absolute;
  top: 4px;
  left: 0;
  width: 22px;
  height: 22px;
  background: #fff;
}

/* highlighted on checked */
input[type="checkbox"]:checked + label::before {
  background: #6505CC;
}

/* Create a checked mark */
input[type="checkbox"] + label::after {
  content: '';
  position: absolute;
  top: 3px;
  left: 6px;
  width: 8px;
  height: 16px;
  border-width: 0 2px 2px 0;
  border-color: #fff;
  border-style: solid;
  transform: rotate(38deg);
}

/* Outline on focus */
input[type="checkbox"]:focus + label::before {
  outline: #5d9dd5 solid 1px;
  box-shadow: 0 0px 8px #5e9ed6;
}