Could you clarify on the 3rd option? I tried to put a file (eg cv.html, which has css styles inside) in content/, then homepage/cv/ displays the HTML as is, which is expected. Then, I add a front matter in front of the html file,
+++ title = "" slug = "" +++
now, this page has a menu on top and the original html below. However, the style is not exactly like the original html: the font has changed. Is there a way to add a frontmatter to a html file, so that there is a menu on top, but keep the html (with build-in css) exactly as is?