## ADDED Requirements

### Requirement: Theme switching accessibility
Theme switching controls MUST be accessible and usable with keyboard and assistive technology.

The theme switcher control MUST:
- be reachable via keyboard navigation
- provide a visible focus indication
- expose an accessible name/label
- allow selecting any supported theme without requiring a pointer

#### Scenario: Theme switcher is keyboard reachable
- **WHEN** a keyboard user tabs through the page
- **THEN** the theme switcher notch receives focus and shows a visible focus indicator

#### Scenario: Theme switcher is labeled
- **WHEN** a screen reader user focuses the theme switcher
- **THEN** it announces a meaningful label and the current theme state

### Requirement: High contrast theme meets WCAG intent
The `high-contrast` theme MUST provide materially higher contrast than the default theme.

The theme MUST keep text readable and interactive affordances obvious, including:
- strong foreground/background contrast
- clearly visible focus ring
- strong borders on interactive elements

#### Scenario: High contrast theme improves readability
- **WHEN** the user enables `high-contrast` theme
- **THEN** primary text and secondary UI labels remain clearly readable and interactive elements are visually distinct
