Hi @bracas,
And turning the relative path to absolute would require customization which we can’t provide, hence, I recommend contacting a developer.
What I was referring is just comparison between images path through HTML, and icons path through CSS. And it’s only normal for CSS to have a relative path which has no performance issues at all. CSS is a static file so it can’t have any absolute path within it, and compared to HTML, paths in HTML are configurable through PHP or any content processing code. While in CSS, it’s not, since they are just CSS code that runs on the browser and not on the server.
Hence, if you really wish to set them into absolute path within CSS, then you must edit the core files and change them and any issues resulted from customization are something we can’t cover. And a developer is more recommended for this changes.
You can also check this https://stackoverflow.com/questions/10058167/wordpress-3-3-relative-paths-in-css
Wordpress is a modular system from different authors and developers, you can’t always set them in the static path, else, it will cause future issues and bug. Like in the migration, backups, and etc.
And htaccess has no relation to the theme, it’s a Wordpress core file for permalinks and rewrite. It would only mask the URL, but it’s still relative to the domain configured in htaccess.
Thanks!