auto-hide bookmarks toolbar - firefox 80

just updated to firefox 80 and the autohide bookmarks toolbar function is broken. 

add in userchrome.css

here is the fix, 

#PersonalToolbar{
  --uc-bm-height: 20px; /* Might need to adjust if the toolbar has other buttons */
  --uc-bm-padding: 4px; /* Vertical padding to be applied to bookmarks */
  --uc-autohide-toolbar-delay: 600ms; /* The toolbar is hidden after 0.6s */
}

:root[uidensity="compact"] #PersonalToolbar{ --uc-bm-padding: 1px }
:root[uidensity="touch"] #PersonalToolbar{ --uc-bm-padding: 7px }

#PersonalToolbar:not([customizing]){
  position: relative;
  margin-bottom: calc(0px - var(--uc-bm-height) - 2 * var(--uc-bm-padding));
  transform: rotateX(90deg);
  transform-origin: top;
  transition: transform 135ms linear var(--uc-autohide-toolbar-delay) !important;
  z-index: 1;

}
#PlacesToolbarItems > .bookmark-item{ padding-block: var(--uc-bm-padding) !important; }

/* SELECT BOOKMARKS TOOLBAR BEHAVIOR */
/* Comment out or delete either one of these to disable that behavior */

/* Show when urlbar is focused */
#nav-bar:focus-within + #PersonalToolbar{
  transition-delay: 100ms !important;
  transform: rotateX(0);
}

show bookmarks toolbar only on new tab - firefox 72

show on new tab as well we focus on address bar and search bar.
in userChrome.css add,

/*bookmarks toolbar on new tabs only */

#PersonalToolbar{
  --uc-bm-height: 20px; /* Might need to adjust if the toolbar has other buttons */
  --uc-bm-padding: 3px; /* Vertical padding to be applied to bookmarks */
}

:root[uidensity="compact"] #PersonalToolbar{ --uc-bm-padding: 1px }
:root[uidensity="touch"] #PersonalToolbar{ --uc-bm-padding: 6px }

#PersonalToolbar:not([customizing]){
  margin-bottom: calc(2px - var(--uc-bm-height) - 2 * var(--uc-bm-padding));
  transform: rotateX(90deg);
  transform-origin: top;
  transition: transform 135ms linear 600ms !important;
  z-index: 1;

}
#PlacesToolbarItems > .bookmark-item{ padding-block: var(--uc-bm-padding) !important; }

/* SELECT BOOKMARKS TOOLBAR BEHAVIOR */
/* Comment out or delete either one of these to disable that behavior */

/* Show when urlbar is focused */
#nav-bar:focus-within + #PersonalToolbar{
  transition-delay: 100ms !important;
  transform: rotateX(0);
}

update*

in firefox 79, you need to enable loading of userChrome.css

follow this guide here

 

bookmarks toolbar remove favicon - firefox 72

to remove favicon on bookmarks toolbar in firefox 72,
in userChrome.css, add this,
(folder is shown as dropdown arrow)

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

#personal-bookmarks .bookmark-item .toolbarbutton-icon {
 display:none!important;
}
#personal-bookmarks .bookmark-item[container] .toolbarbutton-menu-dropmarker {
 display: -moz-box !important;
}

unable to create new library (windows 7)

symptom: when click on the "New library" button on the top of the folder, nothing happens.
also when right click on "Library" on the side bar and mouse over to "New", it says "empty" instead of "New library".

the cause is the missing of the registry code.
here is an article that describes how to fix it.
simply download the No.7 fix "to remove or restore library".

How to Remove and Restore the Default "New" Context Menu Items in Windows 7 and Windows 8