input[type="checkbox"]:before {
    font-family: "FontAwesome";
    content: "\f00c";
    font-size: 15px;
    color: transparent !important;
    background: #fff;
    display: block;
    width: 35px;
    height: 35px;
    border: 1px solid #4770b7;
    margin-right: 7px;
}

input[type="checkbox"]:checked:before{
        color: #547abc !important;
    font-size: 30px;
}