style.css

*{
    margin: 0%;
    outline: none;
    font-family: sans-serif;
}
.container{
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 45px;
}
input{
    margin-top: 30px;
    grid-column: span 4;
    font-size: 60px;
    padding: 10px;
    border-radius: 20px;
    box-shadow: inset 5px 5px 12px white,
                      5px 5px 12px rgb(0,0,0,0.20);
    border: none;
    margin-bottom: 20px;
    text-align:end;
}
.calculator{
    background-color: cornflowerblue;
    border-radius: 20px;
    padding: 20px;
    box-shadow: inset 0px 0px 12px white,
                      5px 5px 12px rgb(0,0,0,0.60);
    display: grid;
    grid-template-columns: repeat(4,100px);
}
.empty{
    border: none;
    height: 0%;
    width:0%;
    background-color: cornflowerblue;
    box-shadow: inset 0px 0px 12px cornflowerblue,
                      5px 5px 12px cornflowerblue;
}
.clear{
    width: 80px;
    border-radius: 20px;
    grid-column: span 1;
}
.cal{
    height: 40px;
    width: 100px;
    border-radius: 20px;
    grid-column: span 1;
    margin-left: 50px;
}
button{
    height: 40px;
    width: 70px;
    border-radius: 50%;
    margin: 10px;
    font-size: 20px;
    border:none;
    box-shadow: inset 0px 0px 12px white,
                      5px 5px 12px rgb(0,0,0,0.60);
}