I wrote up some early thoughts on container style queries a little while back. It's still early days. They're already defined in the CSS Containment Module| CSS-Tricks
The main idea of CSS Container Queries is to register an element as a “container” and apply styles to other elements when the container element meets certain conditions.| CSS-Tricks
Right now, we have the power to write CSS that only applies when the browser window itself is at certain widths or heights. Breakpoints, as it were. Super| CSS-Tricks
I don't know about y'all, but my feeds have been flooded with articles about CSS Container Queries these past few weeks. The buzz about container queries| CSS-Tricks