Responsive Stats Preview Card using Flexbox

Hi! This is my solution to the Stats Preview Card Challenge. My main challenge with this challenge was the responsive part. I am not entirely certain if my use of media queries can be considered best practice, even if the design looks okay on my end.

Along with that, I am not entirely sure if I'm just going insane, but on desktop, it looks like my two boxes don't perfectly align. There seems to be the tiniest height difference although the height of the divs is the same. Is it just optical, am I seeing ghosts?! What's the story here? :')

Any general feedback would be greatly appreciated as well!