Just in plain HTML, CSS and Vanilla JavaScript

I used the most basic frontend skills to create a couple of pages. No fancy frameworks or libraries. I just wanted to explore and catch up on the latest in HTML, CSS and JS.

Just general feedback especially on the code is appreciated. Thanks in advance!

Question: Aside from uploading the solution here and installing axe-core package in the application, do you know of any other tools do you use to resolve accessibility issues? (Some that I found don't detect them until I have uploaded the solution here).

NOTE: The site does not store any credit card information. Please enter only dummy information if you want to test.