div.vis-tooltip {
    position: absolute;
    visibility: hidden;
    font-size: 0.8rem;
    font-weight: normal;
    z-index: 2;
    pointer-events: none;
    white-space: pre-wrap;
    padding: .15rem .4rem;
    margin-left: .25em;
    border-radius: 0.25rem;
    border: 1px solid #ccc;
    box-shadow: 1.5px 1.5px 3px #ccc;
    color: var(--textcolor);
    background-color: #FFFFFF;
    transition: opacity .2s ease-in-out;
}
.expr-tooltip {
    text-align: center;
}