# Petal UX review — 2026-07-27 (implementation doc)

**Origin:** a hands-on browser session against the live VPS deploy
(petal.parodia.dev) on a 1517×810 desktop viewport, deliberately writing
ESL-style English, accepting/undoing suggestions, using Ask Petal, the
right-click dictionary, the Garden, History, and the doc-type menu. Goal:
close the gap to Grammarly's *feel* (latency, stability, proximity of
feedback) without its cost or surveillance.

**How to use this doc:** each item has symptom/repro, likely code location,
proposed fix, and acceptance criteria. Items are ordered by
value-for-effort. Where the session couldn't confirm root cause, that is
said explicitly — verify before building. The product *why* behind Petal
lives in `SUGGESTIONS.md`; execution phases in `BUILD_PLAN.md`. Nothing here
contradicts them; this is polish on the existing loop.

**What was verified working well (don't regress):** error coverage and
explanation quality across two check rounds; bilingual (en+zh) card
explanations; Ask Petal follow-up answers; instant right-click dictionary
with TTS + slow-replay; Garden sprouting; autosave + History snapshots;
kitten cheers on accept; clean console throughout.

---

## 0. DONE this session — kitten yields to cards

The corner mascot's halo sat on top of the bottom rail cards, History-panel
footer controls, and the Garden counter, blocking reading and clicks.

**Implemented (this commit):** when any `.petal-rail-card` overlaps the
mascot badge, the kitten fades to 15% opacity, shrinks 10% toward its
corner (standalone `scale` property, so it composes with the bob
animation's `transform`), and goes `pointer-events: none` so clicks pass
through. It wakes (full size/opacity) while its speech bubble or the
companion picker is open, or when cards no longer overlap.

- `web/src/components/Companion/useCardOverlap.ts` — rect-intersection
  hook, rAF-throttled on scroll/resize + 500 ms poll.
- `web/src/components/Companion/PetalCompanion.tsx` — `faded` wiring.
- `web/src/index.css` — `.petal-companion-faded`, transition.

**Follow-up for Opus:** the overlap check only watches `.petal-rail-card`.
The History panel footer and Garden counter can still sit under the kitten.
Either extend the hook's selector list (`.petal-rail-card, [data-panel]`…)
or give those panels a bottom padding of
`calc(var(--petal-companion-size) * 0.5)`. Acceptance: with History open
and with the Garden footer visible, no interactive control is under the
mascot, or the mascot is faded + click-through.

---

## 1. Bug: redo does not re-apply an accepted suggestion

**Repro:** accept a suggestion (text updates), press Ctrl+Z (text reverts —
correct), press Ctrl+Shift+Z → nothing happens. Observed on the Idiom card
"by foots → on foot".

**Where to look:** `EditorCore.handleAccept`
(`web/src/components/Editor/EditorCore.tsx` ~line 556) applies via
`editor.chain().focus().insertContentAt(range, s.replacement).run()`, which
*is* a normal history transaction — so the break is probably downstream:
after the undo, the parent `onAccept`/re-check flow may dispatch a
transaction that clears the redo stack (any doc-touching tr wipes redo), or
the accepted suggestion's server-side state makes the recheck rewrite
content. Root cause was **not** confirmed in the session — instrument
first.

**Acceptance:** accept → undo → redo restores the replacement; the
suggestion card state stays consistent with whichever text is showing.

## 2. Suggestion stability: stop regenerating the world on every accept

The biggest feel gap vs Grammarly. Today every accept (and every edit)
triggers a full-document `POST /api/docs/:id/check`; all remaining cards
vanish and re-arrive seconds later, spans re-merge into different shapes,
and the LLM re-words every explanation each round (the "weather were" card
carried three different explanations in one session). It reads as
instability, doubles the pause after each accept, and burns qwen3.5 tokens.

**Proposed fix (server + client):**
- Split the doc into sentences (or paragraphs) and hash each. On re-check,
  send only chunks whose hash changed since the last check; suggestions on
  unchanged chunks are returned from cache byte-identical, including the
  explanation text. `internal/suggestions/handlers.go` is the entry point.
- Give suggestions stable identity across checks: key on
  (chunk hash, original span, replacement) so an untouched suggestion keeps
  its `id`, and the client keeps the existing card DOM instead of
  remounting (no vanish/reappear).
- Client: on accept, remove that one card optimistically and leave the rest
  untouched while the changed-chunk recheck runs.

**Acceptance:** accepting one suggestion never changes the text, wording,
or position of any other card; re-check traffic after a one-sentence edit
contains only that sentence's chunk; explanations are stable across rounds.

## 3. Perceived latency: mask the LLM round-trip

Measured ~8–15 s from typing-stop to cards, with only a small "Checking…"
in the status bar. Two independent levers, both worth doing:

- **Incremental surfacing.** Stream/deliver per-chunk results as each
  sentence finishes checking instead of one batch at the end (pairs
  naturally with item 2's chunking). Status bar shows a live count:
  "Found 3 so far…".
- **Instant local rules layer.** A tiny deterministic pass that underlines
  the classics with zero network: a/an before vowel sound, plural after
  some/many/three…, he/she/it + verb-s, common mass nouns ("an
  information"). Petal's ethos (see `SUGGESTIONS.md`: LLM is garnish, plain
  code essential) fits this exactly. Note `grammarLite.test.ts` already
  exists under `web/src/components/Companion/` — check whether a rules
  engine is already half-built before writing a new one. Local hits render
  immediately with a modest style, then get confirmed/enriched (or
  withdrawn) when the LLM pass lands.

**Acceptance:** an obvious error like "a apple" underlines in <100 ms
offline; during a full check, at least one card appears before the last
chunk finishes; the status bar shows a running count.

## 4. Rail scrolls away from the text

With ~7 cards the rail is taller than the viewport; scrolling to reach
lower cards scrolls the document text fully off-screen, severing the
card↔sentence connection.

**Proposed fix:** keep the editor column sticky/pinned while the rail
(`web/src/components/Editor/SuggestionRail.tsx`, `.petal-rail` in
`index.css`) scrolls in its own `overflow-y: auto` container. Preserve the
existing anchor-to-highlight layout for cards that fit; the container only
takes over when the stack exceeds the viewport.

**Acceptance:** with 10+ suggestions, the flagged text stays visible while
scrolling the card list; hover-linking still highlights the right span.

## 5. Mixed-language spans: offer translation, don't ignore

Typed mid-document: 我想说这句话但是不知道用英语怎么说。 ("I want to say
this but don't know how in English") — Petal produced **no card at all**.
The pair model (`SUGGESTIONS.md` §1: user may type in either language,
Petal infers direction) says this should be the flagship moment.

**Proposed fix:** during chunking (item 2), detect spans in the pair's X
language inside an English context (CJK detection already exists for
spellcheck exclusion — see `web/src/components/Editor/SpellCheck.ts`).
Emit a new suggestion type `translate` whose replacement is the English
rendering, card labeled 翻译 · Translate, with the usual
Accept / Ask Petal. Accept replaces the span (keep the original as the
card's strikethrough line so she can still see what she wrote).

**Acceptance:** a Chinese sentence inside an English doc yields a Translate
card within one check cycle; accepting swaps in the English; an
English-only doc and a Chinese-only doc are unaffected.

## 6. Ask Petal answers: bilingual, and room to read

The card's *explanation* is bilingual, but the Ask Petal *answer* came back
English-only, rendered in a small scrollable box inside the card.

**Proposed fix:** prompt the answer path
(`internal/suggestions/chat*.go` / `AskPetal.tsx`) to reply in both pair
languages (native first, mirroring the bubble pattern in
`PetalCompanion.tsx`); let the answer area grow to the card's width with a
sane max-height (~50vh) before scrolling.

**Acceptance:** an Ask Petal answer shows 中文 + English; a 3-paragraph
answer is readable without scrolling a ~100 px box.

## 7. Inline popover at the underline (verify, then strengthen)

Grammarly's core gesture is click-the-word → popup at the word.
`EditorCore.tsx` already has a `hover` card anchored to highlights (see
`handleAccept`'s fallback burst position), and the rail wires
`activeId`/`onHover` both ways — so part of this exists. The session
experience on a wide (1517 px) screen was still: click underline → the
*far-right* rail card expands, ~400 px of eye travel.

**Task:** confirm the hover card appears on click as well as hover, that it
offers Accept + a one-line reason + "more" (expanding the rail card), and
that hover-linking (card ↔ span glow) works in both directions. Fix
whichever half is missing.

**Acceptance:** clicking an underline shows an anchored mini-popover with
Accept, without needing the rail; hovering a rail card glows its span and
vice versa.

## 8. Smaller items (each small, do opportunistically)

- **Accept All per category.** Five tense fixes = five clicks today. Add
  "Accept all Grammar (5)" per category header in the rail, one undo step
  for the batch. Acceptance: batch-accept applies all, single Ctrl+Z
  reverts the batch.
- **Keyboard flow.** Tab/Shift+Tab (or n/p) cycles underlines with the
  popover open; Enter accepts, Esc dismisses popover. Acceptance: a doc
  can be fully triaged without the mouse.
- **Dismissal persistence.** Untested in session: does a dismissed (✕)
  suggestion stay dismissed after the next full re-check? With item 2's
  stable identity, store dismissed keys per doc and filter server-side.
  Acceptance: dismiss → edit elsewhere → recheck → the dismissed card does
  not return.
- **Status-bar summary.** "3 petals to polish 🌸 · 三片花瓣待打磨" next to
  the word count — the gentle version of Grammarly's score. No numeric
  grade, per the north star. Acceptance: count updates live with the rail.

---

## Explicit non-goals (from this review)

- No document score/grade, no streaks-pressure — the Garden and kitten
  already carry motivation warmly.
- No browser-extension-style everywhere-checking; Petal is the writing
  place.
- The doc-type dropdown's translucent look during open was **animation
  mid-fade, not a bug** — leave it.