Article preview using CSS

I initially struggled quite a bit with making the image fill the entire image container on the left. I played around with a-lot of setting and there was a-lot of trial and error trying to get the solution....so much so that I'm actually not sure what i was originally doing to not make it work :/

I wrote some JS to allow the tooltip's position to be dynamic. An event listener on the window will run the position function once the DOM has completely loaded. There is also an event listener that will rerun the position function every time the window is resized.