span.CopyButton {
    position: relative;
}

span.copybutton-tooltip {
    position: absolute;
    visibility: hidden;
    background-color: var(--tooltip-bg-color);
    border: 1px solid var(--tooltip-border-color);
    color: var(--tooltip-text-color);
    font-size: 75%;
    font-weight: normal;
    padding: 0.5em;
    border-radius: 0.5em;
    top: 110%;
    white-space: nowrap;
}

span.CopyButton:hover span.copybutton-tooltip {
    visibility: visible;
}