guideline: Navigable
Help users find their way and know where they are in the website.
2.4.11 Focus Not Obscured (Minimum)
When an element receives focus, it must be at least partially visible.
2.4.12 Focus Not Obscured (Enhanced)
When an element receives focus, it must be fully visible and not covered by other content.
2.4.13 Focus Appearance
The visible focus indicator must be at least 2px thick, have a contrast ratio of 3:1 compared to the unfocused state, and be clearly connected to the focused element.
