[ruslan_mart]

<label>
  <input type="checkbox">
  <span>Я принимаю условия пользовательского соглашения</span>
 </label>

label input[type="checkbox"] {
  opacity: 0;
  pointer-events: none;
  position: absolute;
}

label input[type="checkbox"] + span::before {
  background-position: center center;
  background-repeat: no-repeat;
  background-size: auto 20px;
  border: 1px solid #000000;
  border-radius: 4px;
  content: '';
  cursor: pointer;
  display: inline-block;
  height: 24px;
  margin-right: 8px;
  vertical-align: middle;
  width: 24px;
}

label input[type="checkbox"]:checked + span::before {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' x='0px' y='0px' width='100' height='100' viewBox='0 0 24 24'%3E%3Cpath d='M 20.292969 5.2929688 L 9 16.585938 L 4.7070312 12.292969 L 3.2929688 13.707031 L 9 19.414062 L 21.707031 6.7070312 L 20.292969 5.2929688 z'%3E%3C/path%3E%3C/svg%3E");
}

label input[type="checkbox"]:disabled + span::before {
  cursor: default;
  opacity: 0.5;
}

label input[type="checkbox"]:focus + span::before {
  outline: 1px solid blue;
}