.numpad {
    position: absolute;
    display: none;
    -khtml-user-select: none;
    background-color: #FFF;
    z-index: 1000;
    padding: 5px;
    border: 1px solid #CCC;
}

@media (max-width: 599px) {
    .numpad button {
        width: 70px;
        height: 70px;
        font-size: 30px;
    }
}

@media (min-width: 600px) {
    .numpad button {
        width: 80px;
        height: 80px;
        font-size: 30px;
    }
}

.numpad td {
    width: 70px;
    height: 70px;
    padding: 2px;
}