TB115 seems technically ok but really ugly !
Amongst issues : ugly # of messages, inverted menus, TB overtaking XFCE whan fulll window(like it were fullscreen), undifferentiated messanges lines (I had one white alterning with one lightgrey before).
Css seems unoperative.
Any hint welcome
Since Thunderbird, like Firefox, contains various themes or is easy to install, please try this out.
You can also disable the number of messages.
We just have to get used to the new design. 
I wonder wich marketing genius decided a redesign is due… TB was practically dead a while ago, and still has not a very big user base. But most of it are hardcore fans and longtime users, and they will NOT like the change. Who the hell is TB targeting with this change?..
Short:
Releases · Aris-t2/CustomCSSforTb · GitHub
Phoenity Buttons :: Add-ons for Thunderbird
Phoenity Icons :: Add-ons for Thunderbird
Hide local folders now is build-in, just find it. (…)-Button
Well Supernova was a long time in the works. Also since January 2020 the app is part of MZLA Technologies Corporation when it was before at Mozilla Foundation. It is simple. people don’t like changes to UI. 9 years ago they changed the UI slightly, not so dramatically like now and not everyone was pleased back then.
There was a blog post back in February explaining upcoming changes …
Plus as a company now they have to please their stakeholders and customers, that’s why there is a 3 years plan now.
Well, I need the number of messages, just whitout the ugly round background.
I previously used Phoenity, had to de activate as it’s enormous on 115.
The main issue is not the new default, the issue is to find easy way to amend.
…and to have an app that doesn’t behave as it it were in full screen, hiding my toolbar & dock
I assume it just works fine on Windows 
Really, what did they want to do ??
No global search anymore.
I only see search by mail account…
I’m even checking Evolution and Astroid (I never did as I could stand all TB moves so far, but right now it’s just a failure.)
Unless somebody shows me tricks
Seems you use XFCE and have CSD disabled. You have the global search now in the Headerbar. It now also can search in all modules like calendar. See here.
He starts from scratch… He didn’t update an already existing system. Then it is normal that it almost look fine from him…
You must reset the theme to get something similar to him.
IMHO, supernova is not ready. It is an heresy to have a search bar (and many buttons) on the border used to move the window. Moreover, the Menu under those button is against normal gui design.
There is also many minor thing that make supernova less clear than previous theme, in particular in term of spacing and padding
Edit (because new user cannot reply more than once…)
Is there some way to move the global search bar from the border and put it under the menu?
Resizing column is bugged. Miss the lts version in repositories to wait until bugs are resolved
It is simple. Don’t use any extra theming or plugins for Thunderbird. Install the Gnome Desktop Environment and use the standard Adwaita theme in dark colouring. That’s it. Also you can look into the toolbars under view and select what you don’t want to get displayed.
Ok, I got two things.
Thunderbird 115 lets me customize the theme on KDE. For example:
It looks good to me
Nice, but for some reasons I rather use light theme
Here somme additional help
…but not sufficient at this stage : having an app that doesn’t inherit system theme is irritating and I can’t find how to have every other line be grayed, this doesn’t work.
treechildren::-moz-tree-row(odd) {
background-color: lightgrey !important;
}
The most stupid thing is that the TB’s inspector DOES inherit the theme & font !!
[Edit]this works:
#threadTree tr:nth-child(odd) {
background-color: #f2f2f2;
}
I find quite stupid to have changed CSS class names…
One possibility is:
…move the global search bar…
in userchrome.css choose:
@import “./css/general/tbp_menubar_unifiedtoolbar_tabstoolbar.css”; /**/
Hi, Thunderbird users. I use Thunderbird as RSS reader. Can you tell me how to fix this:
https://i.imgur.com/KsSUzNQ.png
I set dark theme in settings but message pane has still white background.
By the way:
Thunderbird stores feeds news in text files in /Mail/Feeds/ folder but they have html formatting and contain various information.
Is there a script or online service that can convert these files to csv? I want to get rid of everything and keep just news name and url.
Either install an extension like https://darkreader.org/
Or modify the colors in Preferences which can cause some unwanted glitches
