I really like this plugin and use it all the time. Thank you for making it.
One thing that bothers me is that when I open the sidebar, it takes up half of the width of my screen. Then I have to drag the left border with the mouse to make it skinnier.
I note in the advanced settings, it allows me to specify a .css file at ~/.config/joplin-desktop/outline.css. Right now there is no file at that path. I know nothing about css, but is there something I can put there to control the overall width of the outline sidebar without having to adjust with the mouse each time?