CSS with DIV checkbox, the input is not aligned to center of DIV

I have a checkbox that I used in tables and other parts of my web application.

This checkbox is inside a DIV so it has a nicer look and feel.

This is how the checkbox is formed in HTML:

<div class="checkbox checkbox-success checkbox-single">
   <input type="checkbox"><label></label>
</div>

I have detected that when I click in the center of the checkbox it works but If I checked like on the very top left, top right or bottom left it doesn't work.

Then I Inspect the element in Google chrome and found this when I select the input element.

That's why it not working because the input element is not centerd to the div.

I'm using Bootstrap 3.

Here are the CSS that I can see in the Google chrome inspector when I select the input element.

Here are the CSS that I guess are applyed from my Style.css

.checkbox {
  padding-left: 20px;
}
.checkbox label {
  display: inline-block;
  padding-left: 5px;
  position: relative;
}
.checkbox label::before {
  -o-transition: 0.3s ease-in-out;
  -webkit-transition: 0.3s ease-in-out;
  background-color: #ffffff;
  border-radius: 3px;
  border: 1px solid #cccccc;
  content: "";
  display: inline-block;
  height: 17px;
  left: 0;
  margin-left: -20px;
  position: absolute;
  transition: 0.3s ease-in-out;
  width: 17px;
  outline: none !important;
}
.checkbox input[type="checkbox"] {
  cursor: pointer;
  opacity: 0;
  z-index: 1;
  outline: none !important;
}
.checkbox label::after {
  color: #555555;
  display: inline-block;
  font-size: 11px;
  height: 16px;
  left: 0;
  margin-left: -20px;
  padding-left: 3px;
  padding-top: 1px;
  position: absolute;
  top: 0;
  width: 16px;
}
.checkbox.checkbox-single label {
  height: 17px;
}
.checkbox-success input[type="checkbox"]:checked + label::before {
  background-color: #01ba9a;
  border-color: #01ba9a;
}
.checkbox-success input[type="checkbox"]:checked + label::after {
  color: #ffffff;
}

This is breaking my head, any clue?