.fx-checkbox-group-style label {
    float: left;
    min-width: 100px;
    cursor: pointer;
    margin-right: 10px;
    border: 1px solid #AAA;
    background-color: #DDD;
    text-align: center;
    padding: 8px;
}

.fx-checkbox-group-style [type="checkbox"]:checked + label {
    background-color: #0b7b6d;
    color: #FFF;
}