Design (entry)

Design (entry)

Use this skill when the user asks to build or style web UIs: components, pages, dashboards, landing pages, React/Vue/HTML-CSS layouts, or any frontend interface. Goal: distinctive, production-grade output that avoids generic AI aesthetics.

Before reporting any design "done": render it and have a separate judge critique the image (not the code, not self-grading) — see design-spatial §1. Blind generation can't see its own collisions; this applies to all design output, not just spatial work.

MANDATORY HORIZONTAL-OVERFLOW GATE — runs before ANY web UI is "done". Measure document.documentElement.scrollWidth - document.documentElement.clientWidth at a narrow width (~390px and ~1024px), this turn, and confirm it's 0. This bug is invisible at desktop width and re-appears every time a row (header, nav, toolbar) gains an item, so it ships repeatedly. Default to flex-wrap:wrap on header/toolbar rows + body{overflow-x:clip}, and re-measure after adding any element to a horizontal row. Full procedure + recurrence cases: design-spatial §4. If you haven't measured narrow, you are not done — don't claim it.

Sub-skills (load when relevant)

• design-thinking — Load for every design task. Defines purpose, tone, domain, color world, review bar, and cross-domain lens (cinema, architecture, marketing, UX, automotive, industrial design). See design-thinking/SKILL.md.
• design-system — Load when implementing: tokens, typography, motion, color semantics, backgrounds. Use when building components, pages, or design systems. See design-system/SKILL.md.
• design-spatial — Load when composing layout: explicit grid + 8-point spacing constraints, visual-weight/balance/alignment, and a render-then-critique vision loop. The fix for "spatial understanding is off" — generated layout that's centered mush, misaligned, or breaks at some widths. See design-spatial/SKILL.md.
• design-ux — Load when auditing USABILITY (not just looks): a UI that "feels off"/"sucks to use", is hard to learn, needs an instruction wall, or any interactive tool/editor/app before shipping. Scores the rendered UI against Nielsen's 10 + interaction heuristics via a SEPARATE fresh-eyes judge → prioritized fix list. Usability ≠ aesthetics. See design-ux/SKILL.md.
• design-philosophy — Load for high-concept work, campaigns, or when the user asks for a visual philosophy, manifesto, or unmistakable art-like aesthetic. See design-philosophy/SKILL.md.

Visual assets — generate or source

When design-thinking identifies a need for visual assets (logos, icons, hero images, textures, backgrounds):

1. Generate → use an image-generation model or API for synthetic/branded assets.
2. Source a real/archival one → free stock or archival image search, often cheaper and more authentic than generating.
3. Use design-thinking output (tone, domain, color world) to craft prompts / queries.
4. Evaluate against the design philosophy, refine, integrate into the build.

LLM-assisted work — always annotate model + cost

When design work involves running an LLM (generative assets, VLM analysis, layout critique, prompt generation, etc.):

• Before running: state which model will be used and the estimated cost (e.g., "gpt-4o-mini · ~$0.005/image" or "FLUX v1 · ~$0.006 per gen").
• After results: annotate the output with the model used, actual cost if different from estimate, and any key params (seed, prompt, settings). Cost goes visible to the user (in the message, contact sheet header, or asset caption), not buried in logs.
• Why: the user is deciding whether the cost-to-quality trade-off is worth it. Unlabeled or hidden costs hide the most important lever. This rule mirrors media-attribution-rule for generative assets and extends it to any LLM operation in the design workflow.