AnPerello

#main-window[titlepreface*="XXX"] #TabsToolbar
{
    visibility: collapse;
}
/* Auto hide horizontal tab */
#main-window #titlebar {
  overflow: hidden;
  transition: height 0.3s 0.3s !important;
}
/* Default state: Set initial height to enable animation */

morrolinux

What to expect

Graphical aspect may vary depending on your choices in following the instructions below, but the end result should look something like this:

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