button{
    width: 90px;
    height: 90px;
    border-radius: 10px;
    margin: 2px;
    background-color: white;
    color:black;
}


button:hover{
    background-color: rgb(230, 230, 230);
}

button:active{
    border-color: rgb(255, 208, 0);
}

.opt{
    background-color: rgb(255, 208, 0);
}

.opt:hover{
    background-color: white;
}


.kolom{
    width: 370px;
    height: 50px;
    margin: 5px;
    text-align: right;
    font-size: xx-large;
}

.calculator{
    text-align: center;
}