Tab close button on hover (Firefox 120 and newer)

[QNetITQ]

Create a file to add third-party styles (In the options description) and add the code below

/* ---------- Tab close button on hover ---------- */

.tabbrowser-tab:not([pinned]) .tab-close-button
{
    display: none !important;
}

.tabbrowser-tab:not([pinned]):hover .tab-close-button
{
    display: revert !important;
}