See:

• https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XUL/Tutorial/Styling_a_Tree

Do you mean something like this for the border?

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* only needed once */


@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);

.sidebar-placesTreechildren::-moz-tree-row {
  height: 3em !important; /* high value to see whether is works */
}

.sidebar-placesTreechildren::-moz-tree-cell {
  border: 1px solid blue !important;
}

cor-el : My thanks -- your script works !!

To get what I wanted, I just changed the last line to border-width: 1px !important;

Can you help me understand why the original script I posted above does not work? Two differences I see are

• Yours has two @namespace..... lines, one with quotation marks around the http.

• Yours separates the two instructions (for height and for border) into two separate { .... } brackets.

Some properties only work with specific pseudo classes.

Border works with ::-moz-tree-cell and height works with ::-moz-tree-row

• https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XUL/Tutorial/Styling_a_Tree

Thank you !!!

johkeeng said

Thank you !!!

You inadvertenly marked your own post as   'Chosen Solution'   -   you can rectify that by clicking on the   'Undo'  button to the right of that post and then mark cor-el's post as 'Chosen Solution'.

Thank you in advance  !

('Glad your problem got solved  !)

Happy112 - thank you, and ... done.

I also have this problem which also started with FF 56.0.2 on MacOS 10.12 Sierra but am now on OS 10.13.1.

Just to clarify, I want to reduce the spacing in the bookmark sidebar as the gap between items is too wide.

FF seems to ignore my userChrome file altogether. I have put in the code that in on this solution and also the solution in https://support.mozilla.org/en-US/questions/975714#answer-495296 but nothing changes, even when I change the values for height or border width. The .css file is definitely in the right place so some help would be appreciated please.

jaf1948 -- Just copy/paste cor-el's text above into your userChrome.css file, and change the last line to "border-width: 1px !important;". It worked for me. If you don't like the height, you can just edit the height value (I use 1.3 instead of 3).

The text I tried (see 1st post) was from the discussion you found, but it does not work.

I did ask cor-el above if he (or anyone) can explain what is wrong with the initial text (I assume a misplaced punctuation) but no one has volunteered an explanation.

Thank you for the quick reply. I actually did 2 things - having 2 Macs, I copied the working userChrome.css from my other machine and then cut and pasted your text. Everything now works perfectly.

Thanks again.

jaf1948 -- A correction, if you don't mind: It is cor-el's text that worked, so it is cor-el who deserves all the credit !!

Thank you cor-el !