It was there but now.... what?

Ok guys and gals, It’s like that,

I took my first container and duplicate it and put it third and only changed my img link (all the images at the same size) and what? It got bigger, why?

And one more thing, how to I center my btn?
Also, without touching the btn parameters, sometimes the font shrinking and only in 1 btn and comeback to his original size…

My code pen,

Much ablage