re your site being vanilla html i think you can make 11ty build on github pages so you can use that with ejs or nunjucks whichever you prefer
nunjucks is what i use, it’s pretty easy and fun (you can just look at https://www.11ty.dev/ to see how to use it)
i’ll take a look
it is completely in character for me to redo my whole site when i should be asleep
im not gonna lie im incredibly confused and have no idea where to start