When navigating the front-end with a keyboard, some UI elements that are currently in focus, are not highlighted in any way.

Currently highlighting is absent for:

• Buttons with "btn-link" class
• Items in action menu
• "Action links" that open menu overlays or overlays with tables. Visually look like text with a dotted underline. For example: Monitoring>Triggers, Dashboard>Last 20 issues. These are <span> containers, so no option to navigate using a keyboard in the current implementation. The same issue with [X] icon in overlay windows and treeview