#roll_dice {
    order: 100;
    width: 40px;
    height: 40px;
    margin: 0;
    padding: 1px;
    background: no-repeat;
    background-size: 26px auto;
    background-position: center center;
    outline: none;
    border: none;
    cursor: pointer;
    transition: 0.3s;
    filter: invert(1);
    opacity: 0.5;
}

#roll_dice:hover {
    opacity: 1;
}