Change appearance

Task sequence

• Use the header toggle for an immediate explicit light/dark choice.
• Use Account → Appearance to choose System, Light, or Dark.
• Persist the choice under teachkit-theme.
• Resolve System against device preference and synchronize storage changes across tabs.

Data and persistence boundary

Appearance is local preference state, not part of the account form’s save transaction. The before-paint script and provider must follow the same resolution logic.

Failure and recovery

Storage errors are caught and the in-memory preference still applies. Verify fixed-color controls separately in dark mode.

Source references