.custom-checkbox {
    display: inline-block;
    position: relative;
    top: 6px;
    right: 2px;
    width: 20px;
    height: 20px;
    border: 1px solid #a3a3a3;
	border-radius: 3px;
}

input[type=checkbox]:checked ~ .custom-checkbox {
    background-color: #ccc;
	border: none;
}

.custom-checkbox:after {
    content: "";
    position: absolute;
    display: none;
}

input[type=checkbox]:checked ~ .custom-checkbox:after {
    display: block;
}

.custom-checkbox:after {
    top: 50%;
    left: 50%;
    width: 7px;
    height: 11px;
    border: solid white;
    border-width: 0 3px 3px 0;
    transform: translate(-40%, -60%) rotate(45deg);
}