# Consent and Cookie Preferences

## Objective

Let users decide about optional tracking before the scripts load.

A consent layer that blocks non-essential scripts and storage until the user allows them, and records the choice as proof.

## 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. Inventory every script, pixel, embed, and cookie the app sets, and classify each as strictly necessary, functional, analytics, or marketing.
2. Block non-essential categories from loading at all until consent exists. Loading a tracker and then asking is not consent.
3. Store the choice with a version, timestamp, and how it was given, so a later policy change can re-prompt only the people it affects.
4. Give equal weight to accepting and rejecting, and provide a persistent way to reopen preferences and withdraw consent later.
5. Apply the same decision on the server: server-side event forwarding, log enrichment, and backend analytics must read the stored consent rather than assuming the browser handled it.
6. Do NOT gate the app behind the banner or make rejecting harder than accepting. A modal that traps the page or hides the reject option fails the regulation it was built for.

## 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

- Region defaults cannot rest on IP geolocation alone — it is wrong often enough to matter. Combine signals and default to the stricter policy when unsure.
- Withdrawing consent must actively delete the cookies and local storage already set, not merely stop setting new ones.
- The consent record itself is personal data; keep it minimal and covered by the retention policy.
- Third-party embeds such as video players and maps set their own cookies — placeholder them until consent, rather than trusting them.
- A user with consent on one device has not consented on another; the choice is per-browser unless the user is signed in and you sync it.
- The banner must be keyboard-navigable and screen-reader-usable, and must not be the first focus trap a user hits.
- Bots and prerender requests should not create consent records or block essential rendering.

## 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 script and cookie is classified and non-essential ones do not load before consent.
- [ ] Accept and reject are equally prominent and equally easy.
- [ ] Consent is stored with version, timestamp, and source.
- [ ] Preferences can be reopened and withdrawn, and withdrawal clears already-set cookies and storage.
- [ ] Server-side tracking respects the stored consent.
- [ ] Regional defaults do not rely solely on IP geolocation.
- [ ] The consent UI is fully keyboard and screen-reader accessible.
- [ ] 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.