To fulfil accessibility success criterion 2.1.1 "[a]ll functionality of the content is operable through a keyboard interface[...]". In Diamond Theme it is not possible to hide/show navigation by pressing ENTER on the topbar menu button, so this button is not fully accessible by keayboard.
Steps to reproduce the behavior:
- Go to Diamond Showcase
- Use tab key to focus navigation toggle button within topbar.
- Try to trigger the button's action by pressing ENTER key.
- See error > button's action is not triggered i.e. the navigation is not collapsed/expanded.
For accessibility the navigation should be toggleable by pressing ENTER on its toggle button.