Need a simple blank theme to build on with html/css

Hi all,
Previously I have used an older theme “Bootstrap Starter Theme” and it’s worked well, I could choose “Blank no container” and write my own css, and create pages as I wanted them. A long time client now wants to add a blog and for reasons unknown the post portion uses the default theme template instead of “Blank no…”. The creator is no longer maintaining, in fact their website is gone now. Not complaining it served me well.

But I want to find a replacement theme and the ones so far are not working with my current pages. Any suggestions? I’ve been resistant to “Block Editors” I like hand coding, keeps my mind sharper (I’m no spring chicken.. I remember MsDos 1.0 on a single 360k 5 1/4 disc lol)

Any help or suggestions will be appreciated.