In the below R Shiny code, the below HTML/CSS section at the top of the ui is very important in keeping the width of the sidebar panel fixed while the main panel contracts/expands to match the window size as the user adjusts the window, while allowing certain objects like plots to automatically adjust in size, both expanding and contracting (it works great, I don’t want to lose this functionality):

I want to add a css file reference to my htmlTemplate for a shiny application. My current method, pointing to an external file, is not working. Removing and replacing the class attribute with style and adding color directly does work.