input[type='checkbox'] {
    background: #fff;
    border: solid 2px #AD2A1A;
    height: 24px;
    width: 24px;
    -webkit-appearance: none;
    -webkit-border-radius: 4px;
}

input[type='checkbox']:checked {
    background: #fff;
    border: solid 2px #ADABA8;
}

input[type='checkbox']:checked:after {
    content: ' ';
    display: block;
    width: 14px;
    height: 14px;
    background: #C9C7C5;
    position: relative;
    top: 3px;
    left: 3px;
    -webkit-border-radius: 2px;
}