body{
    background-color: white;
}
h1{
    font-size: 50px;
    font-family: 'Times New Roman', Times, serif;
    text-align: center;
}
table{
    margin: 60px auto 60px auto;
    border: 10px double black;
    width:  400px;
    height: 400px;
    background-color: #f2f2f2;
    }

input{
        cursor: pointer;
        width: 100px;
        height: 60px;
            }

#screen{
    cursor: default;
    width: 408px;
    font-size: 40px;
}    

.gr>input{
    background-color: #d2d2d2;
    }
.gr>:hover{
    border: 1px solid black;
}

.wt>input{
    background-color: #f2f2f2;
}

.wt>:hover{
    border: 1px solid black;
}

.bl>input{
    background-color: #498af4;
    }
.bl>:hover{
    border: 1px solid black;
}