.whatever{
    /*background-color: red;*/
    display: inline-block;
    padding:10px 15px;
    vertical-align: top;
    border-radius:6px;
    cursor: pointer;
    border: 1px solid;
}

#checkboxes input[type=checkbox]{
    display: none;
}

#checkboxes input[type=checkbox]:checked + .whatever{
    background-color: green;
}

#checkboxes input[type=checkbox]:disabled + .whatever{
    background-color: #3a3b45;
}

input[type=number]::-webkit-inner-spin-button,
input[type=number]::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}