body, html {
    width: 100%;
    height: 100%;
    margin: 0;
    overflow: hidden;
    font-family: serif;
    color: rgba(0, 0, 0, .77);
}

.tooltip {
    background-color: transparent;
    color: white;
    position: absolute;
    top: 0;
    left: 0;
    padding: 10px;
    opacity: 0;
    transform: translate3d(-50%, -100%, 0);
    transition: opacity .3s, transform .3s;
}

.tooltip.is-active {
    opacity: 1;
    transform: translate3d(-50%, calc(-100% - 25px), 0);
}