Social proof section using HTML and Sass

As basic as it sounds, this is my first time doing a project that is actually laid out differently on desktop vs mobile - as opposed to previous FM projects which have a centre card with very few responsive changes. As a result, my layout is a little weird - it looks great on the provided 1440x800, but looks a little stretched out on my native resolution. I'm looking for a better design methodology to overcome this issue - I'm thinking of either using more relative measurements/fewer absolute measurements, or putting everything in a div and constraining it more to the centre of the screen.

As always, any feedback is welcome!