Intro section with dropdown navigation | Pure CSS, no JS

Hi! This one was pretty fun to make, and hard too! It's my first time making drop-down and sidebar menus, so I struggled a lot. I know I could use JS to get my work done a lot quicker but I wanted to make everything with CSS because I knew it was possible, i've learned a lot thanks to approaching this challenge with only CSS in mind, so any feedback about it is welcome!