Custom checkbox using only CSS and HTML

Answer 1

The problem is that you are using the same pseudo element for the square border and the checkmark. The simple solution would be to continue using the :before pseudo element for the border, and then use an :after pseudo element for the checkmark.

Updated Example

You would have to absolutely position the :after pseudo element relative to the parent .checkbox-custom label element.

Here is the updated code:

.checkbox-custom {
  display: none;
}
.checkbox-custom-label {
  display: inline-block;
  position: relative;
  vertical-align: middle;
  margin: 5px;
  cursor: pointer;
}
.checkbox-custom + .checkbox-custom-label:before {
  content: '';
  background: #fff;
  border-radius: 5px;
  border: 2px solid #ffffd;
  display: inline-block;
  vertical-align: middle;
  width: 10px; height: 10px;
  padding: 2px; margin-right: 10px;
}
.checkbox-custom:checked + .checkbox-custom-label:after {
  content: "";
  padding: 2px;
  position: absolute;
  width: 1px;
  height: 5px;
  border: solid blue;
  border-width: 0 3px 3px 0;
  transform: rotate(45deg);
  top: 2px; left: 5px;
}

Checkboxes

  
  First Choice


  
  Second Choice