button#launch-button {
    position: fixed;
    bottom: 20px;
    left: 30px;
    z-index: 1000;
    display: none;

    opacity: 0;
    animation-name: fadeIn;
    animation-duration: 1.5s;
    animation-delay: 0.5s;
    animation-timing-function: ease-in-out;
    animation-fill-mode: forwards;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@media (pointer: fine) {
    button#launch-button {
        display: block;
    }
}