Change Default CSS for HTML package

Sorry for the likely dumb question, but I was wondering if there was a way to specify what CSS to use in the Unreal Engine itself. I know you can adjust the CSS in the code upon packaging, but would like to tell the engine to package with a CSS that I’d made without having to dive into said code each time I or a teammate packages a product for HTML5. I couldn’t locate any options in the project settings, however.

For instance/to be clear, I can package then change the portion of the HTML file (after opening in Notepad++ or similar, of course) to link another sheet rather than the default maxcdn bootstrap.min.css file it links to, or add/remove buttons below that. Just wondering if there was a way to tell the engine, “Hey, build with Lesson13.css instead of bootstrap.min.css” or similar so that I wouldn’t have to dive into the HTML file after packaging and change it there, as it can become tedious after several teammates continually update and package things based on feedback.

I’ve checked in the Answers hub and didn’t find anything, nor did a quick search in the forums turn up anything. I apologize if I just missed something in any of the locations (forum, engine, or answer hub). I had also asked on the forum, but am in a bit of a time crunch, and thought I’d try my luck here upon having no answers in several days. Apologies if I seem rushed as well. Also sorry if this was the wrong section; Thought Packaging would be the most relevant since it is an option I’m trying to change upon packaging.

For this kind of workflow where you re-export and this re-exporting keeps overriding your manual changes to the .html, probably the simplest way is to copy-paste your modified .html file under a new name, so that when you re-export, it will not get overwritten. The set of web exported pages don’t look at what the exact filename of the .html file is, so you can make a copy and the copy will be referring to the original .js/.wasm/.data files and so on. This way you can keep iterating on modifications to the main .html file while being able to do re-exports as usual.

It’s a tiny hack, but very flexible so hopefully straightforward to adopt.

The .html file is rather static, there’s only few options that affect what gets exported there, so it should be quite easy to diff and adapt if you change any of those features in UE4 export options.

Another way might be to edit the GameX.html.template file in the UE4 installation, but then it would require all team members to do the same mods, and the file would exist in different tree than the project tree, so probably the custom .html method is perhaps the easiest. There currently doesn’t exist a way to feed your own template iiuc, perhaps that might be a feature to request if it’s important and the above workflows aren’t that convenient(?)

I’ll give that a shot, thanks a lot!