Microformats WordPress theme use both worlds: Fixed size layout and responsive technique of scaling to fit the browser width when the browser width is less than 800px.
It supports Article microformats for posts that can be tested from here: https://developers.google.com/structured-data/testing-tool/ (on this URL https://programming-review.com/find-grep/ for example).
It also supports 500+ Google fonts and custom colors, custom site icon, custom header, and custom background image. More it supports, all the theme customizer options like Underscores theme. It should have 0 errors when tested using the Theme check plugin.