.center {
    text-align: center;
}

.button,.rbutton,.sbutton{
    font-family: 'Times New Roman', 'Times', 'serif';
    background-color: rgb(226, 42, 42);
    border: none;
    color: white;
    padding: 4px 8px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 16px;
    margin: 4px 2px;
    border-radius: 8px;

}

.button{
    padding: 0 12px 2px;
    text-align: center;
    font-weight: 800;
}

.rbutton{
    background-color: green;
    cursor: pointer;
    margin-bottom: 25px;

}

.rbutton:hover ,.rbutton:focus{
    background-color: rgb(226, 42, 42);

}
#space-invaders {
    margin: 0 auto;
    display: block;
    background: white;
    max-width: 100%;
}