parcel

Looks like you've done a good job with making things accessible which is great! Looking through I found a couple of things which could be improved.

• The nav button should really be a <button> which toggles aria-expanded when it is clicked. It also needs an accessible name adding
• Opening the nav should trap focus inside the nav until it is closed via the button (or the escape key is presse

Review those available from https://github.com/beberlei/assert and implement without including that library, since there's already quite a bit of overlap with WP's built-ins as well as Stringy