.snowflake {
    position: fixed;
    top: -10px;
    z-index: 99999;
    color: #FFF;
    font-size: 1em;
    opacity: 0.8;
    user-select: none;
    pointer-events: none;
    animation: fall linear forwards;
}

@keyframes fall {
    to { transform: translateY(105vh); }
}