# Decisions — project rules and conventions Compressed log of how things should be done in this project. Read before significant work; append the moment a new rule or convention is settled. See `CLAUDE.md` for format rules. ## Standalone offline exports (super_inline_html) — source-copy convention - **Compiled exports live in `downloads/`, named `Digitální knihovna ČOS - (offline).html`** (`prototyp` · `dataset preview`) — linked from index.html's "Ke stažení" section with the `download` attribute. Re-running `super_inline_html` should output straight to that path. `downloads/` IS part of the deployment upload (see DEPLOY.md). - **Each offline build has a committed `_standalone-src-*.html` source copy next to the page** (`ui_kits/cos-library/_standalone-src.html` = index.html · `_standalone-src-data-preview.html` = data-preview.html). Edit the copy + re-run `super_inline_html` to refresh; never edit the compiled output. - **The copy MUST drop the `@dsCard` first-line comment** — otherwise the export source becomes a duplicate card in the DS tab. - **Preload `preview/_force-state.js` via plain `` (the `.tip` CSS is already global via `_card.css`); in the prototype it's already loaded in `index.html`. - **Usage:** put `data-tip="text"` on any element. For icon-only controls also add `aria-label` (the controller is presentational only — it does NOT supply an accessible name). - **`data-tip-hover` opts a control out of keyboard-focus show (hover-only)** — added Jun 2026. Default behaviour stays hover OR `:focus-visible`; add this attribute when the tip is incidental and the control's state is changed repeatedly via keyboard, so a tip re-firing on every focus/toggle would be noise. Applied to the 2-state theme switch (`comp-switch.html`: live `#tsw1` + the matrix-generated `.tsw` cells). Mirror in `ui_kits/cos-library/tooltip.js` if used there. - **Never use native `title=` for visible tooltips** — can't be styled/animated and double-renders next to the custom chip. **But `title=` is NOT always a tooltip:** ``, `` (component props) and `