# swarm-ui design guide

Scope: **swarm-ui only** (the swarm-level Preact app — not the per-hive
dashboard, which has its own older visual language). This doc is the
*why*: the principles behind how swarm-ui looks and behaves, and the
concrete rules that follow from them. It deliberately doesn't show what
things look like — that's `ComponentsPage` (`/components`), the living,
always-current demo of every primitive in `src/ui/`. Code can't go stale
the way a doc's screenshots can, so treat `ComponentsPage` as the source
of truth for appearance and this doc as the source of truth for intent.
Colour variables specifically are `docs/web-ui/css-vars.md`'s job, not
repeated here.

## Visual language

- **Frosted / tinted glass** where it fits — translucency over flat
  panels, not a hard rule for every surface.
- **Playful use of the multiple accent colours**, without tipping into
  visual noise — the base16 palette has several accent slots
  (`--purple`, `--cyan`, `--pink`, …); use more than one where it adds
  distinction, not decoration for its own sake.
- **Whimsy** — small, delightful touches are welcome (the per-hive
  dashboard's home-page matrix-rain background, `packages/dashboard/src/
  home.js`, is the reference example — currently in the dashboard
  package, not swarm-ui itself, but the pattern it sets applies here
  too). Whimsy still has to clear the accessibility bar below (motion,
  in particular). swarm-ui's own reference example: `Panel`'s optional
  `icon` prop (`src/ui/panel/Panel.tsx`), a small emoji glyph in a
  panel's header, chosen per panel with no default — grew out of a
  one-off emoji dropped into a single page's copy, which wasn't whimsy
  in this sense (a *consistent*, reusable touch) until it became a real
  prop every panel can opt into. `aria-hidden`, since it's decorative —
  the title text is still the actual label.
- **Efficient navigation** — minimize clicks/hops for a common task.
- **Avoid junk drawers.** A control belongs next to the thing it
  affects, not tucked into a catch-all menu. Concrete anti-example (not
  swarm-ui, but the standard to avoid): the per-hive agent terminal's
  model selector living in a three-dot overflow menu instead of next to
  the thing that shows the current model.
- Loosely influenced by Material Design's current (Material You)
  generation, mainly for shape/elevation ideas. Colour is dynamic too —
  auto-derived shades (mixing, lighter/darker) are fair game, same as
  Material's own approach — but every derived colour still traces back
  to the base16/stylix contract below, never an independent source.

## Motion

**General rule, not case-by-case: every non-essential CSS animation
gates on `prefers-reduced-motion` and pauses when its tab/section is
hidden.** The dashboard's matrix-rain background (`packages/dashboard/
src/home.js`/`.css`) is the existing reference implementation of this
pattern — genuinely does both today, confirmed by reading it — even
though it lives in the dashboard package rather than swarm-ui; every
future swarm-ui animation follows the same pattern, not just whimsy
pieces.

Prefer CSS-driven animation over JS-driven where possible, and avoid
jarring content swaps (layout shift, hard cuts) where a transition can
smooth them instead.

## Theming

The mechanical contract (base16 slots, semantic vars, what a page's CSS
is and isn't allowed to reference) lives in `docs/web-ui/css-vars.md` —
read that for the how. This section is the *policy* layered on top:

- **User-theming compatible by construction.** The whole point of the
  base16/`colors.css` swap contract is that a user's own theme (stylix
  today) takes over with zero swarm-ui code changes. Don't build
  anything that assumes a specific palette's exact colours (contrast
  ratios, "this accent is always purple") beyond what the semantic var
  names promise.
- **stylix wins outright when it's active, no in-between state.** When
  an operator has stylix supplying swarm-ui's palette, that palette is
  authoritative — swarm-ui's own light/dark preference (below) doesn't
  override it. This is a deliberate simplification, not a limitation to
  fix: a stylix-using operator has already made their choice.
- **Light theme is accessibility, not a cosmetic extra.** Some people
  need light for contrast/low-vision reasons, others need dark for
  photosensitivity — there's no universally-correct default. The OS
  preference (`prefers-color-scheme`) drives the default, with an
  explicit user override available, same shape as motion above.

## Data freshness & refresh

The governing question for anything that shows time-sensitive data:
**would a user returning to this tab expect current data?** If yes, it
needs a refresh story; a value that's silently gone stale with no way to
tell is worse than one that's visibly stale.

- **Relative-time labels must actually tick.** A label like "fresh (5s
  ago)" is computed from a stored timestamp and re-renders itself on an
  interval — never a value frozen at fetch time that quietly goes stale
  while still reading as current. Pauses while its tab is hidden.
- **Pages that poll get a refresh-interval control, not silent
  staleness.** A small, Grafana-like "refresh every: off / 10s / 30s /
  1m / …" control the operator sets per page, paused while the tab is
  backgrounded and resumed on foreground.
- **A refresh must never clobber input the operator is mid-edit on.**
  Any polling component's contract needs to make this the caller's
  problem to opt out of correctly, not something the next adopter
  discovers by shipping a bug.

## Errors

**`ApiErrorPanel` + the RFC 9457 `ProblemDetails` shape it renders is
the canonical error surface** for every API failure in swarm-ui, not
just its original callers — nobody should build a softer/quieter error
UI later. Concretely: full untruncated `detail`, a copy button, no
"something went wrong, try reloading."

This follows from **power-user-first**, one of the standing principles:
swarm-ui instances are mostly self-hosted and operators are techies, so
errors should give them what they need to actually diagnose a problem
rather than a friendly wall. Power-user-first doesn't mean
newcomer-hostile — the UI should still be self-explanatory, warn or ask
for confirmation before a destructive/dangerous action, and offer
helpful hints — it just shouldn't get in the way of someone who already
knows what they're doing.

## Empty states

Graceful fallbacks, always — a table with zero rows should show
something that represents "no rows" (a real empty-state message), not
just bare column headers floating over nothing.

## Layout & viewport

- **swarm-ui adapts to screen size and fully supports touch** — this is
  not a desktop-only app. Concrete floor: every interactive control from
  the shared `ui/` kit (buttons, inputs, selects) carries a minimum
  touch target (`2.75em` ≈ 44px, WCAG 2.5.5) by default, so this isn't
  something each page has to remember.
- **Phone is a second-class citizen, not an unsupported one.** Things
  must not *break* at phone width, but don't over-invest in phone
  optimization beyond that. swarm-ui is installable as a PWA, so a
  phone can check status or do basic interactions.
- **A narrow viewport isn't only a phone** — a tiling-window-manager
  user with swarm-ui in a narrow tile hits the same layout constraints a
  phone does. Design for the constraint (narrow viewport), not the
  device.

## Component-first design

Build the `src/ui/` primitive before or alongside the first real page
that needs it, not after it's been styled inline and left for later —
a page reaching for a component that's already there has ready-made
blocks to build with, instead of the next contributor duplicating
ad-hoc styling that someone then has to hunt down and consolidate.
`Panel`/`StatusChip`/`Table`/`TextField`/`SelectField`/`Button` are the
primitives that exist; `/components` always has the current, complete
list — this doc won't try to keep a duplicate inventory in sync.

**Every new `ui/` component gets a demo section on `/components` the
same day it lands** — no primitive without a place to see it. One
deliberate exception exists today: `FormField`, the internal label+
control wrapper `TextField`/`SelectField` share, isn't itself a
primitive a page reaches for directly, so it has no demo of its own —
a considered exception, not an oversight this rule missed.

## Attention

"Attention-optimized" here means the system should lead the operator's
attention to where it actually matters (an error, a state change worth
noticing) — not attention-optimized in the engagement/growth sense of
maximizing time-on-page.