td{
    border: 5px solid black;
    border-radius: 25px;
    padding: 7px;
    background-color: rgb(150, 150, 150);
}
div{
    text-align: center;
}
.center{
    margin-left: auto;
    margin-right: auto;
}
.center button {
    width: 50px;
    height: 50px;
    background-color: gray;
    border-radius: 50%;
    border: 4px solid black;
    margin: 1px;
}