1. On codepen for HTML you only need to put the code that's between the
<body> tags, the rest is handled by codepen (you need to include assets like jquery, bootstrap, etc thru settings).
3. As for using an event instead of a person, I can't imagine it being an issue, you've clearly demonstrated an understanding of basic HTML/CSS. The project review team likely focuses on functionality and the user stories rather than content - it also doesn't state a 'person' in the user stories / objective - you should be OK to use an event.
4. I noticed in your CSS some attributes were unnecessarily defined twice, why apply a background color to body and also html? Why not just body?
5. On multiple lines you used to "align" attribute and you shouldn't use that - it's obsolete - a bad habit to get into now - use CSS to align things instead.
6. Line 47 has a stray
<div> tag which isn't needed.
Hope this feedback helps and good luck on your future projects and challenges here at freeCodeCamp