Incorrect focus management upon collapsing Contents

[rhoadsstevens]

Priority level 1 (out of 3) from UW Accessible Technologies

WCAG mapping: 2.4.3 Focus Order

STEPS TO REPRODUCE:

1. Click into any book
2. Open the CONTENTS dropdown
3. Press Esc. or navigate back to the CONTENTS dropdown button and press enter/spacebar.

OBSERVED BEHAVIOR:
When the Esc key is used, the focus indicator disappears. This also occurs when you tab to the CONTENTS dropdown button when it is expanded and use enter/spacebar to collapse it.

In Chrome, there is still no focus indicator, and when you tab, it takes you to the first focusable element within the text.
In Firefox, there is still no focus indicator, and when you tab, it takes you to the "Skip to Main content" button.

EXPECTED BEHAVIOR:
The Esc key should bring you out of the dropdown menu and back to the main banner, specifically to the "Contents" button as that is where the focus initially was before the dropdown was opened.