input[type=checkbox] {
    border: 2px solid green !important;
}

/* this is based on https://github.com/flatlogic/awesome-bootstrap-checkbox */

.checkbox {
  padding-left: 20px;
}
.checkbox label {
  display: inline-block;
  vertical-align: middle;
  position: relative;
  padding-left: 5px;
}
.checkbox label::before {
  content: "";
  display: inline-block;
  position: absolute;
  width: 17px;
  height: 17px;
  left: 0;
  margin-left: -20px;
  border: 1px solid #cccccc;
  border-radius: 3px;
  background-color: #fff;
  -webkit-transition: border 0.15s ease-in-out, color 0.15s ease-in-out;
  -o-transition: border 0.15s ease-in-out, color 0.15s ease-in-out;
  transition: border 0.15s ease-in-out, color 0.15s ease-in-out;
}
.checkbox label::after {
  display: inline-block;
  position: absolute;
  width: 16px;
  height: 16px;
  left: 0;
  top: 0;
  margin-left: -20px;
  padding-left: 3px;
  padding-top: 1px;
  font-size: 11px;
  color: #555555;
}
.checkbox input[type="checkbox"],
.checkbox input[type="radio"] {
  opacity: 0;
  z-index: 1;
}


.checkbox input[type="checkbox"]:focus + label::before,
.checkbox input[type="radio"]:focus + label::before {
  outline: thin dotted;
  outline: 5px auto -webkit-focus-ring-color;
  outline-offset: -2px;
}
.checkbox input[type="checkbox"]:checked + label::after,
.checkbox input[type="radio"]:checked + label::after {
  font-family: "FontAwesome";
  content: "\f00c";
}


input[type="checkbox"].styled:checked + label:after {
  font-family: 'FontAwesome';
  content: "\f00c";
}
input[type="checkbox"] .styled:checked + label::before {
  color: #fff;
}
input[type="checkbox"] .styled:checked + label::after {
  color: #fff;
}