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

a {
    text-decoration: none;
}

.tooltip {
    width: 16%;
    background-color: #fff;
    position: absolute;
    top: 0;
    left: 0;
    padding: 10px;
    font-size: 12px;
    border-radius: 4px;
    display: none;  
    transform: translate3d(-50%, -100%, 0);
    transition: opacity .3s, transform .3s;
    
}

.tooltip.is-active {
    display: block;
    transform: translate3d(-50%, calc(-100% - 20px), 0);
}

.tooltip_img {
    text-align: center;
}

.tooltip_img img {
    width: 100%;
}

#menu {
    position: absolute;
    margin-left: 1%;
    margin-top: 1%;
}

#menu img {
    width: 20%;
}

#menu img:hover {
    cursor: pointer;
}