PS: By the way half of that detail bar is a totally blank space... If anybody here works for firefox you could make it way smaller

I think the reason there is excess space is because that panel is also used for bookmarks, and with bookmarks, that lower part is used for a Keywords field.

Mozilla has a product suggestion site at https://connect.mozilla.org/. I think if you have time, it would be a good idea to post this request (some way to minimize the editing panel in the Library window) there to get into the current feedback stream. Use the "Ideas" section of the site.

I don't think there would be a setting in about:config for this, but there is another level of hackery that usually can resize or hide parts of Firefox's user interface. That's an optional, community-supported (i.e., not officially supported) style rules file named userChrome.css. I have a site with general information on what it can do and how to set it up: https://www.userchrome.org/

The trick is to find rules that do exactly what you want without weird side effects. If you would consider going down this road, I or someone else could take a deeper look.

You can add CSS code to the userChrome.css file in the chrome folder in the Firefox profile folder to hide most of those fields in the detail pane unless you set focus to this area.

• https://searchfox.org/mozilla-release/source/browser/components/places/content/places.xhtml
• https://searchfox.org/mozilla-release/source/browser/components/places/content/editBookmarkPanel.inc.xhtml

@-moz-document url-prefix(chrome://browser/content/places/places.xhtml){
 /* LIBRARY: detailsPane HIDE */
 #detailsPane {height:auto !important; min-height:0px !important}

 /* LIBRARY: detailsPane HIDE not focused */
 #detailsPane:not(:focus-within)
  :is(.editBMPanel_locationRow, #editBMPanel_locationField,
      .editBMPanel_tagsRow, #editBMPanel_tagsField, #editBMPanel_tagsSelectorExpander, #tags-field-info,
      .editBMPanel_keywordRow, #editBMPanel_keywordField, #keyword-field-info) {
   display:none !important;
 }
}

More info about userChrome.css/userContent.css in case you are not familiar: *https://www.userchrome.org/what-is-userchrome-css.html

• https://www.userchrome.org/how-create-userchrome-css.html
• https://www.userchrome.org/firefox-changes-userchrome-css.html

In Firefox 69 and later you need to set this pref to true on the about:config page to enable userChrome.css and userContent.css in the chrome folder.

• about:config => toolkit.legacyUserProfileCustomizations.stylesheets = true
• https://support.mozilla.org/en-US/kb/about-config-editor-firefox

You can add CSS code to the userChrome.css file in the chrome folder

thank you a lot! i always wanted to know how to edit .css. this worked well. I wonder if there is a "bookmark bar autohide" option like "toolbar autohide" in windows