Assessment wanted : Fundamental CSS Comprehension

I have completed the skill test for Fundamental CSS Comprehension and would like to be assessed.

View my code from Glitch

Note: Before even starting the test, I thought the font size was a bit small, so I changed it to 15px from 10px. The instructions demanded all the length values to be in ems. ems depend on font size directly, so the values of width or height may not always be spot on.