scrabble-game/docs/UI_DESIGN.md

# Scrabble Game — UI design system

Visual and interaction conventions for the `ui` client. Behaviour lives in
[`FUNCTIONAL.md`](FUNCTIONAL.md); cross-service architecture (including the global
points this doc references) lives in [`ARCHITECTURE.md`](ARCHITECTURE.md). The client
is **pure HTML5/CSS + Unicode** — no image/font/SVG assets; icons are CSS shapes or
emoji glyphs. Tokens are CSS custom properties (`ui/src/app.css`), light/dark via
`prefers-color-scheme` or an explicit Settings choice, and **Telegram-themed**:
on a Telegram Mini App launch — the app is served under `/telegram/` and detects the
launch by `Telegram.WebApp.initData` — the SDK's `themeParams` override the tokens at
runtime; opened outside Telegram, the `/telegram/` path redirects to the site root.

## Layout shell (`components/Screen.svelte`)

A full-height flex column: the nav bar, the content, and an optional bottom tab bar (the
tab bar always sits at the screen bottom). The **advertising strip** is docked **inside the
nav** (`Header`), directly under the title, so it sits in the same place on every screen. On
most screens the nav is minimal and the **content fills** between nav and tab bar. **Only in
the game** (`growNav`) does the nav bar grow to absorb spare height, so the strip stays under
the title while the board and controls pin to the **bottom** for thumb reach. Every screen
except Login uses `Screen`.

## Navigation

- **Back**: a thin, compact `<` drawn from two rotated CSS borders (`Header.svelte`
  `.chev`) — lighter than a glyph.
- **No hamburger**: navigation is entirely bottom tab bars (the former `Menu.svelte`
  dropdown is gone — it fought the Telegram-fullscreen layout, where it had to be re-centred).
  Destinations beyond the lobby live behind **hub screens** reached from a tab: a ⚙️
  **Settings hub** (`screens/SettingsHub.svelte`, the lobby's ⚙️ tab) and an in-game
  **comms hub** (`game/CommsHub.svelte`, the history's 💬). A hub owns one nav bar + one
  bottom tab bar whose tabs switch its body **in place** (state, not navigation), so the
  back control always returns to the hub's parent (Settings → lobby, comms → game). Settings
  hub tabs: ⚙️ Settings / 👤 Profile / 🤝 Friends / ℹ️ About (Friends hidden for guests);
  comms hub tabs: 💬 Chat / 🔎 Dictionary (Dictionary only while the game is active). The
  routes `/settings|/profile|/friends|/about` and `/game/:id/{chat,check}` survive as hub
  entry points (so a Telegram friend-code deep-link still lands on the Friends tab). The
  **Feedback** screen is its own deeper route `/feedback` (back → `/about`, the Info tab), so
  it slides in/out like a sub-screen rather than switching a tab in place.
- **Tab bar** (`TabBar.svelte`): square, borderless, evenly distributed buttons — a large
  emoji icon over a tiny truncated label (the icon is `aria-hidden`, so the label names the
  button). A press highlights a rounded **square** behind the icon; a hub's **selected** tab
  stays highlighted (a filled
  square with an accent underline). A red count **badge** rides the icon's corner — on the
  lobby ⚙️ tab and the hub's 🤝 Friends tab for pending incoming friend requests (invitations
  keep their own lobby section), and on the Hint tab for the remaining count. No text
  selection on nav / tab-bar / buttons (`user-select: none`).
- **Screen transitions** (`App.svelte`): navigation slides directionally — a
  screen entered from the lobby flies in from the right; returning to the lobby reveals it
  from the left (back). Transitions are local (so they do not play on first load) and
  collapse to nothing under reduce-motion. Per-game and lobby in-memory caches
  (`lib/gamecache.ts`, `lib/lobbycache.ts`) render a re-opened game or the lobby instantly
  and refresh in the background, removing the blank-loading flash and the lobby's "draw-in"
  on lobby ↔ game navigation. The caches are kept fresh **across** screens, so the instant render
  is already current and not a stale frame the background refresh then corrects. The single global
  stream handler (`lib/app.svelte.ts`) is the one place that runs for every live event regardless of
  the mounted screen, so it owns cross-screen freshness: it upserts the affected game's `GameView`
  into the lobby snapshot (`patchLobbyGame`) on every game event — opponent move, game-over,
  opponent-joined, and a match/started game (which it also adds) — patches the lobby's invitations
  list (`patchLobbyInvitation`: a still-pending invitation upserted, a terminal one removed) on the
  `invitation` / `invitation_update` notifications, and advances a not-currently-viewed game's own
  cache from the move/over/joined delta (`advanceCached`, skipping the game in view, whose mounted
  board owns its cache). The game board additionally mirrors the player's **own** move and its own
  `load()` into the lobby snapshot — the two updates no live event carries.
- **Telegram integration** (`lib/telegram.ts`): inside the Mini App the colour
  scheme is forced from `Telegram.WebApp.colorScheme` (over the OS `prefers-color-scheme`,
  which leaks into the Telegram Desktop webview and otherwise fights it) and the Settings
  theme switcher is hidden; the nav bar takes Telegram's background and `setHeaderColor` /
  `setBackgroundColor` / `setBottomBarColor` paint Telegram's own chrome to match; the
  native header **BackButton** drives back-navigation (the app's chevron is hidden in
  Telegram); **HapticFeedback** fires on tile placement / commit / error; on **mobile**
  clients the app enters **immersive fullscreen** on launch (`requestFullscreen`, Bot API
  8.0+) like Telegram's own Mini Apps, while desktop keeps the bot's full-size window;
  **closing confirmation** is enabled while a game is open **on mobile only** (on desktop
  closing is deliberate and the "changes may not be saved" dialog is just noise — move drafts
  auto-save); **vertical swipes** (swipe-to-minimise)
  are disabled so they don't fight tile drag or the board scroll; **external links** (the word-check
  dictionary lookup, the rules link, operator-reply links) open through `Telegram.WebApp.openLink`
  so Telegram shows them in its in-app browser instead of the WebView's "open this link?"
  confirmation a plain `target=_blank` triggers; and a live stream dropped
  by a background suspend reconnects silently on return — the connection banner is
  suppressed while hidden and for a short grace after resume (visibilitychange +
  pageshow/pagehide + Telegram `activated`/`deactivated`).

## Tiles & board

- **Tiles**: the letter sits in the **top-left** corner (offset a touch more than the
  value), the point value bottom-right; blanks show no value.
- **Board zoom** (`Board.svelte`): a two-state zoom (full 15×15 ↔ ~9 cells) by **growing
  the board's width** inside a fixed-size viewport (a real layout change → native scroll
  that works consistently across browsers; no `transform`, which broke scrolling
  differently in Safari/Chrome). Labels are sized in `cqw` against the fixed viewport, so
  they stay a constant size as the cells grow (relatively smaller at higher zoom).
  **Double-tap** an empty/filled cell toggles zoom centred on it; double-tap a **pending**
  tile recalls it. **Pinch** zooms toward the pinch midpoint (a two-finger gesture;
  preventDefault fires only for two touches, so one-finger scroll stays native, and a second
  finger aborts an in-progress drag). The pan is **interpolated toward a pre-clamped target**
  as the real width grows/shrinks, so it magnifies evenly A→B instead of lurching and snapping
  back near the edges. It **recentres only on a zoom-in** — placing a 2nd+ tile or
  hovering a dragged tile never jumps the board. On touch the first tile placement auto-zooms
  in centred on the target, and **holding a dragged tile over a cell ~1 s** auto-zooms there
  the first time. A **swipe down on the zoom-out board** opens the history, but only when the
  board is scrolled to its top so it never fights the stage's own vertical scroll (the conflict
  that once retired this gesture) — and it is suppressed on the zoomed board, where the
  one-finger drag pans. History also opens on a **tap of the score bar** and closes on a tap or
  an **upward swipe** of the then-inert board (below). A **hint** auto-zooms centred on the
  hint's placement, not
  the top-left.
- **Placing & recall** (`Game.svelte`): a rack tile is placed by tap-then-tap or by
  dragging it onto a cell; while a dragged tile is carried over the board, the aimed-at empty
  cell is **highlighted as a drop target** (an accent ring). A pending tile is taken back by a
  **double-tap** or by **dragging it back onto the rack** (unzoomed board only — when zoomed
  the one-finger gesture scrolls). A single tap no longer recalls (too easy to trigger); a
  recalled tile returns to its original rack slot.
- **Players plaque & history** (`Game.svelte`): the seats above the board share
  the width evenly; the seat whose turn it is is **raised** (a drop shadow on its sides)
  while the others read **sunk in** (an inset shadow). A tap on the plaque toggles
  the **move history** — a fixed-height slide-down drawer whose bottom border (and its
  shadow) pins to the board as the board slides down, instead of tracking the table as
  moves accumulate; its scrollbar gutter is reserved so the centred cells do not jitter. The
  history is a **ruled matrix** — one column per seat, aligned under the score plaques, each
  seat's moves filling its column top to bottom: no player names (the plaque heads the column)
  and no running total, just the word(s) and the move score, `WORD (12)`, centred. A non-play
  move keeps its dim parenthesised tag `(pass)`; the seat whose move is awaited shows a dim
  `thinking…` in its next cell (never the viewer's own). While the history
  is open the **slid board is inert** and the stage cannot scroll, so the whole board reads
  as a **tap-or-swipe-up-to-close** surface — closing genuinely clears the open state (it no
  longer merely scrolls the board out of view, which used to leave a stale-open state that
  made a follow-up plaque tap "jump" the board). The drawer carries its own **header**: a 🏁
  **Drop game** (or 📤 **Export GCG** on a finished game) at the left and the comms 💬
  (badged with unread chat) at the right, icon-only. A **single-word-rule** game (a Russian
  game with "multiple words per turn" off) centres a **"One word per turn"** label between
  those two icons, and the status bar shows a small **1️⃣** in the score-preview slot that
  yields to the live word/score preview while tiles are pending; standard games show neither. Each **opponent**'s card also gains a
  🤝 **add-friend** control (non-guests; hidden once a friend, disabled once requested) that
  confirms via the fading-✅ tap, swapping the card's score for "Add friend?" while armed
  (see Controls); the name and score stay centred — the 🤝 is pinned to the card's edge.
  Unread chat is also badged on the score bar itself, so it shows with the history closed.
- **Vertical fit & keyboard**: when the game does not fit the viewport, only the
  board area scrolls vertically (`Screen` `column` mode; the score bar, status, rack and tab
  bar stay fixed), while zoom keeps its own scroll. The check-word dialog opens in
  `Modal` keyboard-overlay mode — the small sheet is top-anchored and the soft keyboard
  overlays the empty area below, so the layout doesn't resize/jank; other modals stay
  keyboard-aware (they size to the area above the keyboard).
- **Landscape (wide) layout** (`Game.svelte`): when the viewport is wider than tall
  (`matchMedia('(orientation: landscape)')`) the game switches from the portrait stack to a
  **two-column** layout. The board fills the **right** column; it fits by **height** as a square
  (`min(100cqw, 100cqh)`, height-driven in `Board.svelte`'s `.scaler.land`) inside a
  `container-type: size` pane, shrinking by width when the column is narrow — the board has the
  **lowest priority**, so the left panel is never squeezed. The **left panel** stacks, top to
  bottom: the score plaques, the **always-open** history (docked and scrolling with its header
  sticky — no slide-down drawer, no score-bar toggle), the status line (bag · turn · score
  preview), the rack (+ the ✅ make control) and, pinned at the bottom, the controls tab bar. Board
  **zoom works as in portrait** (double-tap / pinch / placement auto-zoom), but the viewport is the
  full pane: zoom-out shows the height-fitted square centred, and zoom-in magnifies the board past
  the pane and pans within it, occupying the full width up to the left panel (the focus-centred
  scroll is set directly, without the portrait width-progress tween). Only the history open/close
  swipes are dropped (it is always open) and the nav bar does not grow (`growNav` off). The
  portrait layout is byte-for-byte unchanged; both layouts render from the same snippets, so the
  behaviour and markup stay single-sourced. The rack tiles size to the (fixed-width) panel rather
  than the viewport width so seven tiles never overflow the column.
- **Highlights**: pending tiles use a slightly darker tile background (no outline). The
  last completed word keeps the normal tile background; instead its letters — not the point
  values — are drawn in the recent-move colour, in both themes. It is static while it is the
  opponent's turn (our word), and a 1 s flash (the letter pulses between its normal colour
  and the recent-move colour) when it is our turn (their word). While placing, only the
  pending tiles are highlighted.
- **Bonus-square labels** — a Settings choice (`boardlabels.ts`): `beginner` shows a
  split `3×` / `word` (localized слово/буква), `classic` a single `3W` / `3С`, `none`
  nothing. Default **beginner**.
- **Grid lines** — a Settings toggle, **default off**. Off: a **gapless
  checkerboard** — plain cells alternate two shades, and tiles get rounded corners with a
  soft right-side shadow so adjacent gapless tiles still read apart, reclaiming ~14px of
  board width. On: the classic lined grid, where the inter-cell gap shows a contrasting
  `--cell-line` (darker in light, lighter in dark) to avoid a wavy-line optical illusion.

## Controls

- **TapConfirm** (`components/TapConfirm.svelte`, logic in `lib/tapconfirm.ts`): the shared
  tap-to-confirm control. A first tap arms a ~2 s window showing a **fading ✅** (no fade
  under reduce-motion, but the window still holds); a tap on the ✅ within it confirms,
  otherwise it reverts. Used by the **Hint** tab (the icon morphs to ✅, no label — replacing
  the old press-and-hold popover) and the in-game **add-friend 🤝**. The
  **Drop game** action keeps its `Modal` confirmation (a destructive, less-frequent action).
- **MakeMove / Reset**: when ≥1 tile is pending the rack collapses its used slots
  and shifts left, a **borderless ✅ icon button** (styled like a tab, not a filled accent
  button) beside the rack commits the move — no popover, and disabled while the pending word
  is known illegal; the 🔀 Shuffle tab is replaced by a **↩️ Reset** tab.
- **Game tab bar**: 🔄 Exchange/Pass (opens a dialog — pick tiles to **Exchange N**, or pick
  none to **Pass without exchanging**; pass is always available on your turn, exchange only
  while the bag still holds a full rack, below which the tiles disable and only the pass
  remains), 🛟 Hint (with a remaining-count badge, disabled at zero); 🔀 Shuffle (no label,
  no confirm), which
  **animates** — tiles hop along a low parabola to their new slots (duration scaled by the
  distance, the longest ≤ 0.3 s; off under reduce-motion) with a short haptic shake. The
  under-board slot shows the **Scores: N** preview. The screen **title** is the variant's
  display name (Scrabble / Скрэббл / Erudite / Эрудит), not a constant "Scrabble".

## Advertising banner (`components/AdBanner.svelte` in `components/Header.svelte`, `lib/banner.ts` + `lib/bannerEngine.ts`)

A one-line inset strip docked inside the nav bar, directly under the title (so its position never
jumps between screens), drawn on a dedicated `--ad-bg` token — a subtle accent, a touch darker than
the surroundings in the light theme and a touch lighter in the dark theme, mapped to Telegram's
`secondary_bg_color` inside the Mini App. Content is minimal markdown (text + links, escaped +
linkified). It is **server-driven**: the campaigns and display timings ride the `profile.get`
response (`app.profile.banner`, present only for an eligible viewer — see ARCHITECTURE §10), so
`Header` renders the strip only when that block is present, and a `notify` `banner` event re-fetches
the profile to show or hide it in place.

The rotation runs in a **persistent module engine** (`lib/bannerEngine`): the scheduler and timer
live outside the components, so navigating between screens (which remounts the view) **continues the
cycle** rather than restarting it. A mounted `AdBanner` reads the engine's live message at init and
renders it **immediately, without a fade** (`bannerCurrent`), and attaches only as the DOM host — so
a screen change does not replay the fade; only a real message advance fades. A **smooth weighted
round-robin** (`createScheduler`) picks the next message: campaigns compete by their weight (each
appears its weight share per cycle, evenly interleaved, not at random), and a campaign's own messages
advance round-robin. One message fades in (`fadeInMs`), holds `holdMs` (a message wider than the
strip pauses `edgePauseMs`, scrolls to its right edge at `scrollPxPerSec`, pauses, and — while still
under `holdMs` — fades out, rewinds to the start hidden, then fades the **same** message back in to
scroll again), then fades out (`fadeOutMs`), waits `gapMs`, and the next fades in. The fade (opacity
on a `.fadewrap` layer) is independent of the scroll (the inner track's transform). **Every** cycle
boundary fades — a message change, a scroll rewind, and a **lone** message (which pulses out and back
in rather than sitting frozen) — so the rhythm is uniform. So the strip does not jump in height while
the message is momentarily gone during `gapMs`, it reserves one text line with an invisible spacer
and overlays the message absolutely. When a navigation remounts the view mid-scroll, the engine
**resumes the scroll from where it had reached** (`resumeScroll`) instead of restarting it at the
left. A **viewport size change** (e.g. a portrait↔landscape rotation) re-measures the current message
(`remeasureBanner`, debounced), so its scroll re-evaluates for the new width. All timings are
operator-set (`/_gm/banner-settings`). Under **reduce-motion** the fades collapse to an instant swap
and a long message does not scroll.

## Result / status iconography (`lib/result.ts`)

Lobby rows show two lines (opponents, then result + score) with a large place-based emoji
on the right: Victory 🏆 / Defeat 🥈 / Draw 🏅, and for 3–4-player games II 🥈 / III 🥉 /
IV 🏅; active games show Your move 🟢 / Opponent's move ⏳; invitations use 💌. When a listed
game **becomes your turn or finishes** while the lobby is open, that status emoji **blinks
twice** (a two-cycle opacity fade, ~2 s; suppressed under reduce-motion) to draw the eye — the
opponent's-turn change is silent. Each card's blink is keyed by game id, so overlapping
events animate in isolation, and the newest bottom toast cancels the previous one and replays
its entrance (`components/Toast.svelte`, re-keyed on a per-message sequence).

**Simultaneous-game cap.** When the player is at the active-quick-game cap (`games.list`
`at_game_limit`), the lobby's **New Game** tab is **disabled** (greyed via the shared
`.tab:disabled` opacity) and a plain, low-emphasis line — muted, centred, no accent — sits
under the lists with the localized "limit reached" notice. Both follow the flag carried in the
cached lobby snapshot, so they render in their last-known state on entry (the button stays
enabled on the first, uncached load) and flip in place when an event refreshes the lobby.

## Social, account & history surfaces

- **Settings hub** (`screens/SettingsHub.svelte`, the lobby ⚙️ tab): one nav bar + a bottom
  tab bar over four bodies — ⚙️ Settings, 👤 Profile, 🤝 Friends, ℹ️ About — switched in
  place; back always returns to the lobby. Guests see all but Friends. The lobby ⚙️ badge and
  the 🤝 tab badge both show the pending incoming-friend-request count.
- **Friends** (`screens/Friends.svelte`, the Settings hub's 🤝 tab): an "add a friend" block
  pairing a code **input** with a **Show my code** action that reveals a large 6-digit
  code + its expiry; then the incoming **requests** (Accept / Decline), the **friends**
  list (Remove / Block), and a **blocked** list (Unblock). Durable accounts only — a
  guest sees a sign-in prompt.
- **Invitations**: a lobby **section** (a 💌 row per open invitation) with Accept /
  Decline for an invitee and a waiting/Cancel state for the inviter; a single-word-rule
  invitation adds a **"One word per turn"** line to the card. Creating a game lives in
  `NewGame.svelte`: **"Play with friends"** (pick invitees, then variant / move time /
  hints) and **quick game**. Quick game opens with a two-button **🤖 AI / 👤 Random player**
  segmented select (the `.seg`/`.opt` style, **AI the default**) in place of the old subtitle — AI
  is an honest robot you knowingly play, Random player is auto-match against a human. The variant plaques are
  **mutually-exclusive selects** — a tap **highlights** one (an accent inset border) instead
  of starting a game; a lone offered variant is pre-selected, and a bottom **Start game**
  button (disabled until a variant is chosen) confirms. For a **Russian** variant (either
  flow) a **"Multiple words per turn"** checkbox (`.toggle`, **default off** = the single-word
  rule) appears once that variant is selected; English variants never show it. Starting an
  auto-match **enters the game immediately** and waits inside it: until an opponent joins, the
  opponent's score card (and the game's lobby row) reads the localized **"searching for opponent"**
  placeholder, the add-friend 🤝 is hidden, and resign and the chat's send/nudge are disabled; an
  **opponent_joined** push restores them in place when a human or robot takes the seat, and a line
  under Start game notes the wait can take a while (the app may be closed meanwhile). With **AI**
  selected there is no wait: the move-clock line instead reads **"Loss after 7 days of inactivity"**
  and the "searching" hint is hidden; the game starts already seated, the opponent shows as **🤖**
  everywhere (score card, lobby row, turn line), the add-friend 🤝 is never drawn, and the chat's
  send field and 🛎️ nudge stay **disabled** while the 🔎 dictionary word-check keeps working.
- **Statistics** (`screens/Stats.svelte`, the lobby ✏️ tab): a 2-column grid of stat
  cards (games / wins / draws / losses / moves / hint-share / best game / win-rate) —
  pure numbers, no charts; hint-share is a one-decimal percentage in the active locale's
  notation (e.g. "4.8%" / "4,8%") — followed by a **full-width "best move" card** that
  breaks the best move
  down per variant: one row per played variant (catalogue order, empty variants
  omitted) with the variant name on the left, the **word drawn as game tiles**
  (`components/WordTiles.svelte`, the board's placed-tile look at a small fixed size;
  a wildcard shows its letter but no value) right-aligned to a shared edge, and the
  score right-aligned in its own column.
- **Profile editing** (`screens/Profile.svelte`): an inline form — display name, a
  **UTC-offset** timezone dropdown (defaulting to the browser's offset), the away
  window as hour + 10-minute dropdowns (24-hour, ≤ 12 h), and block toggles — plus an
  email-binding sub-flow (enter email → enter the confirm code on a numeric field).
  Invalid fields show a **red border** (no message) and **Save stays disabled** until
  every field is valid. Interface language stays in **Settings** (it writes through to
  the account for durable users).
- **Friend code**: the issued code sits next to a 📋 copy control; tapping the code or
  the icon copies it. **Share via Telegram** wraps the code in a `t.me/<bot>/<app>?startapp=`
  deep-link and opens Telegram's native share-to-chat sheet (Web Share / clipboard fallback
  outside Telegram); the link and its caption are for the **same bot the player signed in
  through** (its service language). Redeeming your **own** invite shows a friendly note, not an
  error; opening an **outdated** invite link (a used or expired single-use code) lands in the
  lobby with a calm modal pointing at the right bot (`@<username>`), not a red error on the
  Friends tab. Flex text inputs carry `min-width:0` so they shrink instead of overflowing in
  Safari.
- **History / GCG**: the in-game slide-down history lays each move out in a per-seat grid
  (the word(s) and the move score, no running total); *Export GCG* (the 📤 in the history
  header) shares or downloads the `.gcg` file and appears only once the game is finished — and
  never in an honest-AI game (throwaway practice). Confirming a resign reveals the full board:
  it closes the history drawer (portrait) and zooms the board out.
- **Finished game**: the board keeps no last-word highlight and no zoom; the history header
  offers *Export GCG* (not *Drop game*; an AI game offers neither) and the comms hub hides the 🔎 *Dictionary* tab; and
  the footer (rack + tab bar) is **drawn but inert** (greyed, non-interactive) rather than
  hidden, so the layout does not jump. Chat send / nudge are the ⬆️ / 🛎️ icons. The input
  row is turn-driven: on your turn the message field shows until your one allowed message is
  sent, then a short caption replaces it until the next turn; on the opponent's turn the 🛎️
  nudge takes the field's place.
- **Feedback** (`screens/Feedback.svelte`, reached from a button at the bottom of the ℹ️ Info
  tab, registered accounts only): a multi-line message field over a row that pairs a **ghost**
  attach button (a hidden `<input type=file>`, with a chosen-file name + a remove control) with
  the filled accent **Send** button. A rejected file shows one generic notice (the allowed types
  are not advertised). The send controls disable while a previous message is under review or the
  account is barred; the operator's reply renders below as a titled block. An undelivered reply
  raises a badge on the lobby ⚙️ tab (combined with the friend-request count) and a "1" on the
  Info tab.

## Caveat

Emoji are rendered by the platform's system emoji font, so their exact look varies across
OSes — acceptable for the MVP, and consistent with the no-asset rule (no glyphs are
downloaded).