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

.tooltip .tooltiptext {
    visibility: hidden;
    width: 200px;
    background-color: yellowgreen;
    color: #fff;
    text-align: center;
    border-radius: 6px;
    padding: 8px;
    position: absolute;
    z-index: 1;
    margin-left: 20px;
    transition: opacity 0.3s;
    font-weight: bold;
}

.tooltip .tooltiptext::before {
    content: "";
    position: absolute;
    top: 25%;
    left: -22px;
    margin-top: -15px;
    border: solid 10px transparent;
    border-right-color: yellowgreen;
}
.tooltip:hover .tooltiptext {
    visibility: visible;
    opacity: 1;
}