Hi Loady, this is as tight as I can get with the full size site icons:

#toolbar-menubar .menu-text, #toolbar-menubar .menu-accel-container {
  -moz-appearance: none !important;
  line-height: 16px !important;
  max-height: 16px !important;
  padding-top: 0 !important;
  padding-bottom: 0 !important;
  margin-left: 10px !important;
}
#toolbar-menubar .menu-text {
  margin-left: 10px !important;
}
#toolbar-menubar .menu-iconic-left, #toolbar-menubar .menu-iconic-text {
  -moz-appearance: none !important;
  line-height: 16px !important;
  max-height: 16px !important;
  padding-top: 0 !important;
  padding-bottom: 0 !important;
}
#toolbar-menubar .menu-iconic-left {
  padding-left: 3px !important;
}
#toolbar-menubar .menu-iconic-text {
  padding-left: 7px !important;
}

Some do not shrink as much as others, but I didn't see an immediate explanation.

Thanks, I'll give it a go and let you know. Much appreciated!

- Loady

Hi again,

I tried it, but it seems to have no effect at all.

I created a clean userChrome.css file (in the chrome directory) with the namespace line at the top, and pasted your code in below. I've tested other stuff this way, and it usually works.

I'm using Linux and Firefox 57.0.

Any ideas?

Cheers!

- Loady

Maybe it's the font. I confess limited familiarity with Linux. Do you want to post a screenshot of one of the menus (please cut out or blur any sensitive information in the image before attaching it to your reply using the Browse button below the text box).

Hi again,

Still won't work. Tried in both Linux and Windows.

Have enclosed a screenshot. This is showing the unchanged bookmark menu.

I can't figure it out :(

- Loady

Hi again,

Still won't work. Tried in both Linux and Windows.

Have enclosed a screenshot. This is showing the unchanged bookmarks menu.

I can't figure it out :(

- Loady

That does look like normal spacing. Sorry, I can't explain it.

Setting only a negative margin-top and margin-bottom is sufficient for me.

menupopup :-moz-any(menu,menuitem) {
  margin-top:-6px!important;
  margin-bottom:0px!important;
  pading-top:0px!important;
  padding-bottom:0px!important;
}
#bookmarksMenu menupopup :-moz-any(menu,menuitem) {
  margin-top:-4px!important;
  margin-bottom:-4px!important;
}
menupopup :-moz-any(menu:first-child,menuitem:first-child) {margin-top:0px!important;}
menupopup :-moz-any(menu:last-child,menuitem:last-child) {margin-bottom:0px!important;}

Thanks to both of you for your help.

I just tried cor-el's answer, and it seems to work very nicely. Just had to adjust it a little for my spacing taste ;)

Cheers.

- Loady