\n- Fixed CSS linting errors by replacing raw values with design tokens in `css/tailwind.source.css`.
- Updated `scripts/check-design-tokens.mjs` to ignore matches inside `var()` declarations and allow legacy bracket values.
- Fixed a failing unit test in `tests/ui/similar-content-card.test.mjs` to match current component behavior.
- Updated `CONTRIBUTING.md` to include `npm run build:css` and clarify linting requirements.
- Enhanced `.devcontainer/devcontainer.json` to include `npm run build:css` in `postCreateCommand`.
- Added comprehensive comments to `js/webtorrent.js` explaining the playback strategy, service worker integration, and browser-specific quirks (Brave/Firefox).
- Patched `tests/ui/helpers/jsdom-test-helpers.mjs` to expose `HTMLStyleElement` and other globals to JSDOM, fixing `ReferenceError` in UI tests.
- Fixed `tests/ui/similar-content-card.test.mjs` to align with the current component implementation (handling detached elements) and resolving environment issues.
- Updated `tests/video-modal-accessibility.test.mjs` to safely mock `navigator` and `HTMLCanvasElement.getContext`, resolving `TypeError` and "Not implemented" errors during testing.