Изменение внешнего вида чекбоксов и радио-кнопок с помощью CSS

<label class="input-wrap">One
  <input type="radio" checked="checked" name="radio">
  <span class="checkmark"></span>
</label>

<label class="input-wrap">Two
  <input type="radio" name="radio">
  <span class="checkmark"></span>
</label>

<label class="input-wrap">Three
  <input type="radio" name="radio">
  <span class="checkmark"></span>
</label>

<label class="input-wrap">Four
  <input type="radio" name="radio">
  <span class="checkmark"></span>
</label>

/* Customize the label (the container) */
.input-wrap {
  display: block;
  position: relative;
  padding-left: 35px;
  margin-bottom: 12px;
  cursor: pointer;
  font-size: 22px;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}
 
/* Hide the browser's default checkbox */
.input-wrap input {
  position: absolute;
  opacity: 0;
  cursor: pointer;
  height: 0;
  width: 0;
}
 
/* Create a custom checkbox */
.checkmark {
  position: absolute;
  top: 0;
  left: 0;
  height: 25px;
  width: 25px;
  background-color: #eee;
}
 
/* On mouse-over, add a grey background color */
.input-wrap:hover input ~ .checkmark {
  background-color: #ccc;
}
 
/* When the checkbox is checked, add a blue background */
.input-wrap input:checked ~ .checkmark {
  background-color: #2196F3;
}
 
/* Create the checkmark/indicator (hidden when not checked) */
.checkmark:after {
  content: "";
  position: absolute;
  display: none;
}
 
/* Show the checkmark when checked */
.input-wrap input:checked ~ .checkmark:after {
  display: block;
}
 
/* Style the checkmark/indicator */
.input-wrap .checkmark:after {
  left: 9px;
  top: 5px;
  width: 5px;
  height: 10px;
  border: solid white;
  border-width: 0 3px 3px 0;
  -webkit-transform: rotate(45deg);
  -ms-transform: rotate(45deg);
  transform: rotate(45deg);
}

/* Customize the label (the container) */
.input-wrap {
  display: block;
  position: relative;
  padding-left: 35px;
  margin-bottom: 12px;
  cursor: pointer;
  font-size: 22px;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}
 
/* Hide the browser's default radio button */
.input-wrap input {
  position: absolute;
  opacity: 0;
  cursor: pointer;
  height: 0;
  width: 0;
}
 
/* Create a custom radio button */
.checkmark {
  position: absolute;
  top: 0;
  left: 0;
  height: 25px;
  width: 25px;
  background-color: #eee;
  border-radius: 50%;
}
 
/* On mouse-over, add a grey background color */
.input-wrap:hover input ~ .checkmark {
  background-color: #ccc;
}
 
/* When the radio button is checked, add a blue background */
.input-wrap input:checked ~ .checkmark {
  background-color: #2196F3;
}
 
/* Create the indicator (the dot/circle - hidden when not checked) */
.checkmark:after {
  content: "";
  position: absolute;
  display: none;
}
 
/* Show the indicator (dot/circle) when checked */
.input-wrap input:checked ~ .checkmark:after {
  display: block;
}
 
/* Style the indicator (dot/circle) */
.input-wrap .checkmark:after {
  top: 9px;
  left: 9px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: white;
}