Clipboard Landing Page (Junior)

Just finished this one and although it took a while, I don't think I hit too many walls where I was left scratching my head. I tried to lay out my code clearly so would love some feedback on this (e.g. CSS contents and sections).

As a side question - how advanced should someone be before being ready to apply for some junior level web dev roles? Should I be able to complete the advanced challenges on here with ease before I even think about applying for some jobs? I'm definitely nowhere near ready yet, but it would be interesting to know what to aim for.

Thank you again.