# Interface Design

Build product interfaces with the craft of a top design team — Linear, Vercel, Stripe, Apple. The difference between those and generic output is not talent. It is that every decision was *decided*, the hierarchy is unmistakable, and a hundred small details are correct at once. This skill is how you get there.

## Scope

**Use for:** Dashboards, admin panels, SaaS apps, tools, settings pages, data interfaces.

**Not for:** Landing pages, marketing sites, campaigns, brand-only work. Use a marketing/frontend design skill for those.

This skill is self-contained: direction, visual hierarchy, design-system architecture, and the polish and motion essentials needed to ship production-grade UI all live here.

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# The Problem

You will generate generic output. Your training has seen thousands of dashboards, and the patterns are strong. You can follow this entire process — explore the domain, name a signature, state your intent — and still produce a template: warm colors on cold structures, friendly fonts on generic layouts.

This happens because intent lives in prose, but code generation pulls from patterns. The gap between them is where defaults win. Process helps, but it doesn't guarantee craft. You have to catch yourself, and you have to know the concrete moves that defaults don't.

**The bar:** If another AI, given a similar prompt, would produce substantially the same output, you have failed. Not different for its own sake — different because the interface emerged from *this* user, *this* task, *this* world. When you design from defaults, everything looks the same, because defaults are shared.

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# Where Defaults Hide

Defaults disguise themselves as infrastructure — the parts that feel like they just need to work, not be designed.

- **Typography feels like a container.** But type isn't holding your design, it *is* your design. The weight of a headline, the personality of a label, the texture of a paragraph shape how the product feels before anyone reads a word. Reaching for your usual font means you're not designing.
- **Navigation feels like scaffolding.** But navigation *is* the product — where you are, where you can go, what matters. A page floating in space is a component demo, not software.
- **Data feels like presentation.** But a number on screen is not design. What does it *mean* to the person looking? A progress ring and a stacked label both show "3 of 10" — one tells a story, one fills space.
- **Token names feel like implementation detail.** But `--ink` and `--parchment` evoke a world; `--gray-700` and `--surface-2` evoke a template. Someone reading only your tokens should guess what product this is.

There are no structural decisions. Everything is design. The moment you stop asking "why this?" is the moment defaults take over.

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# Intent First

Before touching code, answer these. Keep it a compact working brief unless the direction needs user confirmation.

- **Who is this human?** Not "users." The actual person. Where are they when they open this? What did they do 5 minutes ago, what will they do 5 minutes after? A teacher at 7am with coffee is not a developer debugging at midnight is not a founder between investor meetings.
- **What must they accomplish?** The verb. Grade these submissions. Find the broken deployment. Approve the payment. The answer determines what leads, what follows, what hides.
- **What should this feel like?** In words that mean something. "Clean and modern" means nothing — every AI says that. Warm like a notebook? Cold like a terminal? Dense like a trading floor? Calm like a reading app? This shapes color, type, spacing, density — everything.

If the prompt is too vague to identify the human, task, and feel, ask one concise question. If context allows a responsible assumption, state it briefly and proceed.

**Intent must be systemic.** Saying "warm" then using cold colors is not following through. If the intent is warm: surfaces, text, borders, accents, semantic colors, type — all warm. If dense: spacing, type size, information architecture — all dense. Check every token against the stated intent. For every choice — layout, color temperature, typeface, spacing scale, hierarchy — you must be able to say *why*. "It's common" or "it works" means you defaulted.

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# Product Domain Exploration

This is where defaults get caught — or don't. Generic path: Task type → visual template → theme. Crafted path: Task type → product domain → signature → structure + expression. The difference is time spent in the product's world before any visual thinking.

**Produce all four before proposing any direction:**

- **Domain** — concepts, metaphors, vocabulary from this product's world. Not features — territory. Minimum 5.
- **Color world** — what colors exist *naturally* here? Not "warm" or "cool" — go to the actual world. If this product were a physical space, what would you see? List 5+.
- **Signature** — one element (visual, structural, or interaction) tha

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