Structs UI

You are being asked to build something, not to play. This skill routes you to the reference material for making an interface that looks like Structs and a client that behaves like one.

Everything below is verified against structs-webapp, the flagship client — not inferred from the API surface. When a doc and that codebase disagree, the codebase wins.

Not this skill? If you want to build structs — the in-game machines — that is structs-building. If you want to use the Desktop MCP tools, that is TOOLS.md.

When to use it

Building a dashboard, form, menu, HUD, or companion app for Structs.
Styling anything so it reads as part of the Structs universe.
Writing client code that signs transactions, computes proof-of-work, or listens to GRASS.
Extending Structs Desktop with a new MCP tool or board page.

Decide these first

Decision	Guidance
UI or client?	Visuals → the SUI pages. Chain, events, work → the client pages. Most real projects need both
Scaling model	The game renders at `scale(2)` above 1152px. At 1× SUI is half size. Settle this before writing markup — retrofitting is painful. ui/
Which SUI JS	Import each class directly with `.js`. Never import `SUI.js` outside a bundler — it has an extensionless import that 404s and takes the module down. ui/runtime
Serving assets	SUI’s URLs are root-absolute. From a subpath, every icon vanishes silently. Serve at root or rewrite. ui/gotchas
Extend or build fresh	Adding to Structs Desktop is usually cheaper than a new app. client/desktop-extensions

Five rules that make it look like Structs

Nothing is rounded. Hard edges, 1–2px borders, border-radius: 0.
Emphasis is colour and case, never weight. Font weight is 500 everywhere.
Chrome is uppercase 8px ExtremeHazard; content is 16px DirectiveZero.
Colour comes from tokens and is semantic. Teal is you, red is the enemy, amber is warning, gold is third parties. Never a hex literal.
Density over whitespace. This is an operations console, not a landing page.

And one that saves an hour: never invent an icon. There are 67 glyph icons and 29 sprite icons. If the concept has no glyph, use a text label — no emoji, no inline SVG.

Where to go

Interface — develop/ui/

Need	Page
Colours, spacing, z-index, type	tokens
The two icon inventories	icons
Markup contracts for every component	components
Steppers, tooltips, the drawer	runtime
Why the layout is broken	gotchas
Keeping a multi-page console coherent	patterns
Dashboard, form, menu, HUD, assembled	recipes
Runnable starter files	examples

Client — develop/client/

Need	Page
The three-channel architecture	index
State, factories, the string-number trap	state-and-data
Wallet, signing queue, charge gating	actions-and-signing
Proof-of-work: hashing, difficulty, workers	work-and-pow
Real-time events and all 26 listeners	realtime-grass
PFP compositing, struct art, Lottie	rendering-entities
Ambits, tiles, fog of war	map
Adding an MCP tool or board page	desktop-extensions

Context — repos (which repository to read, and which wins) · frontend-architecture (the webapp’s MVVM layer) · maintenance (how these pages stay true)

Traps, in the order you will hit them

Assets don’t resolve. Icons and form art vanish with no console error. Check document.fonts.check('16px Structicons') first, always.
Everything is centred. body { text-align: center } is inherited by everything; only eleven rules re-assert left. Left-align data surfaces explicitly.
A flex item won’t shrink. min-width: auto is the default. word-break does nothing about it — you need min-width: 0.
Alert severity colours the icon but not the text. The text hard-sets --text-body. Four CSS rules fix it; they are in sui-patch.css.
Copy the typos. --from-input-height-content and sui-message-system-model-frame-center are the real names.
Two transactions at once gives account sequence mismatch. Serialise — one in flight, one per block. Don’t track sequence numbers.
Charge gates actions. currentBlock - (lastActionBlock + 1). Hold the queue until the confirmed last-action height has loaded, or the client will think it has infinite charge and empty its queue into one block.
Proof-of-work is cheaper if you wait. Difficulty decays with anchor age. Initiate early, complete later.
Numbers arrive as strings. Normalise once at the boundary. The reference client is inconsistent about this; don’t copy that part.

Before you call it done

Every colour from a token, every icon from the real inventories
Form controls unclassed inside label.sui-input-text; checkbox container is a <div>
tabular-nums on numeric cells, min-width: 0 on flex items with long text
Empty, loading and error states share one component and look different from each other
Sweep for overflow at your narrowest width — jsdom won’t catch it, only a browser will
Keyboard focus is visible somewhere (SUI removes the default and adds nothing back)
Transaction failures reach the operator — the reference client’s settled event has no listeners, so failures are silent by default

Full checklist: ui/patterns.