Hmm, looks like there's been another update to my new favorite Firefox extension, Tab Sidebar. Nice changes on balance: It seems a bit more polished now, and among other things, the thumbnails have some mini-navigation controls. But, now there's too much crammed in there for my 12" screen.

So, I've started hacking my userChrome.css again:

#sidebar {
    min-width: 0px !important;
    max-width: none !important;
}
#sidebar-title { display: none !important }
sidebarheader  { display: none}
    
.tbs-tabpreviews .tbs-close   { display:none !important; }
.tbs-tabpreviews .tbs-favicon { display:none !important; }
.tbs-tabpreviews .tbs-title   { font-size: 0.825em !important; }

.tbs-tabpreview:hover .tbs-canvas, 
.tbs-tabpreview[selected="true"] .tbs-canvas {
    opacity: 1 !important;
}
.tbs-tabpreview[selected="false"] .tbs-canvas {
    opacity: 1 !important;
}

Unfortunately, that last bit with the opacity doesn't work. I want to disable the dimming of unselected tabs, so that all tab previews are 100% opaque at all times and not just when selected. See, I don't need the current tab to be fully clear—it's what I'm looking at right now. I need all the other tab previews to be as clear as possible.