Calculator.css

.calculator-holder {
        position: relative;
        top: 50%;
        transform: translateY(+50%);
}
.calculator
{
        width:300px;
        height:300px;
        background-color:#eeeeee;
        border:2px solid #CCCCCC;
        margin:0 auto 0 auto;
        padding-left:5px;
        padding-bottom:5px;
}
.calculator td
{
        height:16.66%;
}
.calc_td_result
{
        text-align:center;
}
.calc_result
{
        width:90%;
        text-align:right;
}
.calc_td_calculs
{
        text-align:center;
}
.calc_calculs
{
        width:90%;
        text-align:left;
}
.calc_td_btn
{
        width:25%;
        height:100%;
}
.calc_btn
{
        width:90%;
        height:90%;
        font-size:20px;
}