.est-tooltip-container {
    position: relative;
    display: inline-block;
    cursor: pointer;
}

.est-tooltip {
    visibility: hidden;
    background-color: #333;
    color: #fff;
    padding: 6px 10px;
    border-radius: 4px;
    position: absolute;
    bottom: 125%; /* above the container */
    left: 50%;
    transform: translateX(-50%);
    white-space: nowrap;
    font-size: 13px;
    z-index: 1000;
    opacity: 0;
    transition: opacity 0.2s;
}

.est-tooltip::after {
    content: "";
    position: absolute;
    top: 100%; /* arrow at bottom of tooltip */
    left: 50%;
    margin-left: -5px;
    border-width: 5px;
    border-style: solid;
    border-color: #333 transparent transparent transparent;
}

.est-tooltip-container:hover .est-tooltip {
    visibility: visible;
    opacity: 1;
}