Space Learning Website UI/UX Design

This is a UI design of a fictional website that offers free education about space for kids. The dark color represent the dark of the space, while the green color stands distinguishly among the dark background as the center of attention as well as colorful aspect since this website is for kids.

I'm currently still learning to do UI/UX design, I highly appreciate your feedbacks.

Feel free to give any feedbacks in the comment section, thanks :)