Discourse theme component making the posts a bit wider, filling the empty space (configurable) before the timeline like suggested here https://meta.discourse.org/t/increasing-post-width-with-css/43368/8.
Works in the standard themes, Sam's Minimal theme. May not be compatible with some themes.
https://meta.discourse.org/t/how-do-i-install-a-theme-or-theme-component/63682