.stooltip {
    position: relative;
    display: inline-block;
    border-bottom: 1px dotted black;
}

.stooltip .tooltiptext {
    visibility: hidden;
    width: 240px;
    background-color: black;
    color: #fff;
    text-align: left;
    border-radius: 6px;
    padding: 10px;
    font-size: 14px;

    /* Position the tooltip */
    position: absolute;
    z-index: 1;
    bottom: 100%;
    left: 50%;
    margin-left: -60px;
}

.stooltip:hover .tooltiptext {
    visibility: visible;
}