Images hover text

Site URL: https://potato-sphere-g3k8.squarespace.com/config/?frameUrl=/about

Hi! How do I set all text to be the exact size of these images on all devices? And for the black background to fill the whole picture without a scroll. I shortened the text for the top images but for some reason they aren't expanding to the exact size of the images. As well, is there a way to add a slide up effect for the text? Thanks!! @tuanphan

edit max-height: 100%;

to

height: 100%;

Thank you!!!!!