I have Thunderbird 68.5.0 (32-Bit) for Windows. The distance between lines in the message list and in the folder-list is too big and also the font-size in the message list and in the folder-list is too big.
I have been told that there should be a CSS file to edit in the Thunderbird profile folder, but I have found none.
So how can I customize the font-size and line-distance (line height) in the Thunderbird message list and folder-list?