# State Color Matrix

## Objective

Define how every control looks in each interaction state, once, instead of screen by screen.

A matrix pairing each interactive component with its default, hover, active, focus, selected, disabled, and loading treatment.

## Before You Begin

This feature is being added to an application that already exists and already
works. Do not scaffold a new project, and do not assume a blank slate.

Inspect the codebase first and establish:

- The existing application structure and where code of this kind already lives.
- The framework and version in use.
- The existing design system — colours, spacing, typography, and component conventions.
- Existing UI components you can reuse instead of writing new ones.
- The existing database structure, if this feature needs to persist anything.
- The existing authentication and authorization system, if this feature is user-scoped.
- Dependencies already installed, so you don't add a library that duplicates one.
- The existing test setup and conventions.

Only start writing code once you understand the above. If the application
already implements part of this feature, extend it rather than replacing it.

## Implementation Instructions

1. Enumerate the interactive components — buttons, links, rows, cards, tabs, menu items, form controls — and fill in every state for each, so that the combinations nobody thought about are visibly blank rather than silently absent.
2. Check contrast in every state, not only the default one. Hover and disabled treatments are where text most often drops below threshold, and disabled is where teams most often assume the rules no longer apply.
3. Treat hover as an enhancement that touch users will never see. Any meaning carried only by a hover treatment — that a row is actionable, that an item can be removed — must also be carried by something permanent.
4. Make selected, active, and disabled distinguishable from one another by more than colour: a selected row and a disabled row rendered as two shades of the same grey are indistinguishable to a large number of users and identical in a forced-colours mode.
5. Do not change an element's box dimensions on state change. Adding a border on hover or thickening one on selection reflows the row underneath; keep the border present and change only its colour, or draw it inside the element's own box.

## UI and UX Requirements

Match the application's existing design system exactly. Reuse its components,
spacing, and typography. This feature should look like it was always there.

## Responsive Requirements

Works on mobile, tablet, and desktop. Touch targets are large enough to hit on a
phone, and nothing overflows horizontally at 320px.

## Accessibility Requirements

- Fully keyboard navigable.
- Correct semantic elements and ARIA roles.
- Visible focus states.
- Meets WCAG AA contrast.
- Dynamic changes are announced to screen readers.
- Respects prefers-reduced-motion.

## Edge Cases

- Contrast must hold in every state, including hover, selected, and disabled — a disabled label is still read, and a low-contrast hover makes text briefly unreadable at the exact moment someone is aiming at it.
- Hover cannot carry meaning on touch devices, where it either never fires or sticks after a tap, so anything discoverable only on hover is undiscoverable to most mobile users.
- Selected, active, and disabled must be distinguishable from each other and from focus without relying on hue alone, since colour-vision differences and forced-colours modes collapse them together.
- State changes must not alter the element's dimensions, or the layout shifts under the pointer and the row moves out from under the click.
- States combine: a selected row that is also hovered and also focused needs one defined result, not three treatments layered until nothing is legible.
- Focus ring geometry, offset, and clipping belong to the Focus Ring System; this matrix owns only the colours the focus state uses, and must not specify a second ring.
- A loading state on a control must remain visibly the same control at the same size, so the button does not shrink to a spinner and take the layout with it.

## Testing

Exercise the feature end to end in the running application. Cover every edge case
above, then run the existing test suite and confirm nothing regressed.

## Acceptance Criteria

- [ ] Every interactive component has a defined treatment for default, hover, active, focus, selected, disabled, and loading.
- [ ] Contrast requirements are met in every state, including disabled.
- [ ] No affordance or meaning is conveyed by hover alone.
- [ ] Selected, active, focus, and disabled are distinguishable without relying on colour alone.
- [ ] No state change alters an element's dimensions or shifts surrounding layout.
- [ ] Combined states have a single defined result.
- [ ] Focus ring geometry is delegated to the Focus Ring System rather than redefined.
- [ ] The feature matches the existing design system.
- [ ] No existing functionality is broken.

## Adaptation Rules

- Match the existing design system. Do not introduce a new colour palette,
  spacing scale, or component library.
- Reuse existing components and utilities wherever they fit.
- Follow the naming, file layout, and code style already present.
- Do not upgrade, replace, or remove existing dependencies to make this
  feature fit. Adapt the feature to the app, not the app to the feature.
- Do not break existing functionality. If a change is genuinely required in
  existing code, make the smallest one that works and say so.
- If something in these instructions conflicts with how the application is
  built, follow the application and explain the deviation.

## Final Verification

Before you report the work as done:

1. Re-read the acceptance criteria above and check each one against what you
   actually built.
2. Run the application and exercise the feature end to end.
3. Run the existing test suite and confirm you have broken nothing.
4. Check the feature on mobile, tablet, and desktop widths.
5. Check keyboard navigation and focus handling.
6. Summarize what changed: files added, files modified, and anything you
   deliberately did differently because of how this application is built.

If any acceptance criterion is unmet, fix it before reporting completion.