I noticed on codepen when looking at other people’s projects that the css and html are separate, but when going through the learning exercises it was all written together . Can I make my code the way we learned it, or do I have to have separate html and css sections?Thanks:)
If you want to write code as you learned, I suggest you use a different tool. For example repl.it
Some things to note when using CodePen:
1)CodePen expect the content of the body tags in the HTML box and of the style in the CSS box.
2) All meta, link, and script information must be put in the 
settings section of the HTML editor.
3) You do not need to/cannot link the CSS in your HTML, if you place the CSS in the appropriate section.
4) If your project uses React, use the Babel preprocessor, and link the CDN in the appropriate section.
5) The editors offer the ability to format and analyse your code, providing useful information about forgotten closing tags etc.
If you are still confused with how to use CodePen, please read the official documentation.
Hope this helps
thank you so much!