Personal Portfolio - height:auto not working

max-width: 80%; works fine, but height: auto is ignored.
my codepen url : https://codepen.io/irakli12345/pen/MqggXP
for reference, see “image-and-annotation” and “project-image” classes.
http://prntscr.com/kkfmet

NOTE: I think i fixed it. Problem was that “align-items” property was set to “stretch” by Flexbox (that’s default), then i gave “align-items” value of “center” and it’s working now.