#map-tooltip {
    position: absolute;
    border: 1px solid white;
    background: black;
    border-radius: .4em;
    max-height: 50px;
    width: auto;
    padding: 5px;
    z-index: 999999;
    color: lightpink;
}

    #map-tooltip:after {
        content: '';
        position: absolute;
        bottom: 10px;
        left: 50%;
        width: 0;
        height: 0;
        border: 20px solid transparent;
        border-top-color: black;
        border-bottom: 0;
        margin-left: -25px;
        margin-bottom: -20px;
    }