CSS should set font dimensions so that normal page/article text (accounting for any sidebars, etc.) should have 9-12 words per line for unjustified text. (ref: https://www.fonts.com/content/learning/fontology/level-2/text-typography/length-column-width). Other sources cite 60-75 characters including spaces which I guess has similar results (ref: https://baymard.com/blog/line-length-readability).
Currently we have a rather wide main content area design which would likely result in quite large text. So we should ask ourselves how much space we want to dedicate to sidebars (in a responsive way where sidebars appears/dissappear dynamically) and other content or if the website width should be reduced in general.