In searching for a fix to the Firefox 89 Proton layout catastrophe, I found a very neat site which tries to summarize all the fixes that can be made in “userChrome.css” file, which can be found in about:profiles
internal URL, and enabled with toolkit.legacyUserProfileCustomizations.stylesheets
in about:config
.
Unfortunately, it’s not possible to restore the menu icons, as of yet, but it’s still a relief from that disaster.
This is my hack for Linux:
/*** Tighten up drop-down/context/popup menu spacing ***/
menupopup > menuitem, menupopup > menu {
padding-block: 4px !important;
}
:root {
--arrowpanel-menuitem-padding: 4px 8px !important;
}
/*** Proton Tabs Tweaks ***/
/* Adjust tab corner shape, optionally remove space below tabs */
#tabbrowser-tabs {
--user-tab-rounding: 0px;
}
@media (-moz-proton) {
.tab-background {
border-radius: var(--user-tab-rounding) var(--user-tab-rounding) 0px 0px !important;
margin-block: 1px 0 !important;
}
#scrollbutton-up, #scrollbutton-down { /* 6/10/2021 */
border-top-width: 1px !important;
border-bottom-width: 0 !important;
}
/* Container color bar visibility */
.tabbrowser-tab[usercontextid] > .tab-stack > .tab-background > .tab-context-line {
margin: 0px max(calc(var(--user-tab-rounding) - 3px), 0px) !important;
}
}
/* Inactive tabs: Separator line style */
@media (-moz-proton) {
.tabbrowser-tab:not([selected=true]):not([multiselected=true]):not([beforeselected-visible="true"]) .tab-background {
border-right: 1px solid rgba(0, 0, 0, .20) !important;
}
/* For dark backgrounds */
[brighttext="true"] .tabbrowser-tab:not([selected=true]):not([multiselected=true]):not([beforeselected-visible="true"]) .tab-background {
border-right: 1px solid var(--lwt-selected-tab-background-color, rgba(255, 255, 255, .20)) !important;
}
.tabbrowser-tab:not([selected=true]):not([multiselected=true]) .tab-background {
border-radius: 0 !important;
}
/* Remove padding between tabs */
.tabbrowser-tab {
padding-left: 0 !important;
padding-right: 0 !important;
}
}