StyleSeed

Your AI writes UI that looks like an AI wrote it.
StyleSeed is the design engine that fixes that.

_{Design judgment for Claude Code · Codex · Cursor · vibe coding — so the output stops looking generated.}

One component. Three brand DNAs. Same chat UI morphing across Toss · Raycast · Arc — colors, radius, motion, shadows, gradients all driven by StyleSeed tokens. Just a data-skin attribute.

 

Every design-AI skill makes your UI coherent. StyleSeed also fights the generic-AI look — and enforces it.

Judgment, not data — how designers think, not a palette collection  ·  Fights the AI tells — the default indigo, the icon-chip cliché, template layouts, rainbow lists  ·  A scored Quality Gate — reviews + fixes to ≥80/100 before you see it  ·  Every agent — ships CLAUDE.md + AGENTS.md + .cursorrules  ·  A design lock that stops drift  ·  Free & MIT

_{Full pages: before · after · more before/afters →}

_{Same product, six looks — each one /ss-restyle <preset> away. Coherent, distinct, never generic.}

Get Started · Engine + Skins · Motion · Skills · Wiki · 한국어

The fastest way — paste this one sentence into Claude Code, Codex, Cursor, or any AI agent. It installs StyleSeed and runs the whole loop:

Install StyleSeed so its checks actually run: `npx skills add bitjaru/styleseed` (if you can't, read https://styleseed-demo.vercel.app/llms-full.txt instead). Then use it for every UI in this project. First, in plan mode, lock my key color, font, and motion with me and save them to STYLESEED.md so they don't drift. Build to the rules with ONE focal point and one accent. Before showing me anything, run the quality gate (/ss-score to ≥ 80: one accent, one radius, normal states grey not rainbow, real empty/error states) and fix what fails. If you're building a full screen, just run /ss-build — it enforces this whole loop.

Why the prompt installs first: the quality gate is the step that makes output stop looking generic — but /ss-score and /ss-build can only run if the skills are installed. Point an agent at the rules-URL alone and the "gate" degrades to an honor-system self-check it usually skips. Installing makes the loop real: the lock persists in STYLESEED.md (no drift), and the gate actually scores and fixes before you see anything. Can't install? The URL still teaches the rules — just weaker. Works with Claude Code (CLAUDE.md), Codex / Amp / Gemini CLI (AGENTS.md), and Cursor (.cursorrules) — StyleSeed ships all three. (Planning first is what keeps the result from looking random — see Troubleshooting.)

What your agent actually does with StyleSeed loaded:

you    ▸  build me a billing settings page
agent  ▸  (plan mode) key color? for billing I'd go deep teal — #0F766E, mood: sharp · calm ·
          trustworthy (not the default indigo). Motion: Snap. ok?  ▸ y
agent  ▸  ✓ wrote STYLESEED.md — skin, accent, font, radius, motion locked, re-read every prompt
agent  ▸  building… running the quality gate before I show you anything
gate   ▸  ✗ two accent colors   ✗ "normal" rows colored   ✗ no empty state   → fixing
agent  ▸  ✓ 88/100 — one accent, grey normal states, real empty/error states. here's the page.

The STYLESEED.md lock is the anti-drift mechanic. Your skin, key color, radius, and motion get written once and the rules make every agent re-read and obey them on every prompt — so the design stops being different each session. The Quality Gate then self-reviews and fixes the UI (rainbow lists, two accents, missing states) before you ever see it — and it can retrofit an old generic build too.

The rules are the product — and they need zero install or permissions. They're plain markdown (CLAUDE.md / AGENTS.md / DESIGN-LANGUAGE.md), so the prompt above — or just copying those files in — is 90% of StyleSeed with nothing to approve.

Want the /ss-* slash-command skills too (optional automation: setup wizard, review, score)?

npx skills add bitjaru/styleseed

Installs all 19 skills into Claude Code, Codex, Cursor, Gemini CLI, Amp and more — then run /ss-setup. Your agent will ask you to approve them once on first use (standard for any executable skill). No install possible? The rules alone still do the core work.

Your agent, its exact path:

_{More paths (manual copy, Cursor, awesome-design-md brands) in Install by hand below.}

• You asked Claude Code or Cursor to build a dashboard and it came out amateur-looking
• You're vibe coding a SaaS app and don't want to hire a designer
• You use shadcn/ui but the output still feels generic
• You want Toss-style refinement without reverse-engineering it yourself
• You're building a Claude Code skill or Cursor rules setup for design
• You ship fast with AI and need professional UI that doesn't look AI-generated

There are lots of "help your AI design" projects now. Most solve a slice. StyleSeed is the one that targets the whole "looks AI-generated" problem — and enforces the fix.

They're not all competitors — a DESIGN.md gives StyleSeed a skin; a generator gives it a first draft. StyleSeed is the judgment + enforcement layer the others don't have.

The kind of specific, named calls a senior designer makes without thinking — written down so an AI applies them every time:

• The refined black is #2A2A2A, not #000 — a 5-step grayscale ramp, never pure black
• One accent, everything else greyscale — the single-accent law; a second hue is the fastest "un-designed" tell
• Numbers 2:1 with their unit — a 48px value over a 24px unit; equal sizes flatten magnitude into noise
• Nested-radius law: inner = outer − padding — concentric corners, so a card and its inner button agree
• Layered, low-opacity shadows (≤8%) lit from one direction — not one hard drop shadow
• Tabular numbers for anything that updates — no width jitter as values change
• Status color = severity only — a "normal" row is grey; color marks the exception, never a rainbow list
• No emoji icons, and no Lucide-in-a-pale-chip on every card (§CC-9b) — the two opposite AI icon tells
• 8px spatial grid; gap-around-a-group > gap-inside it — proximity that reads as structure
• Optical, not pixel, alignment — nudge arrows/play glyphs; center type by cap-height
• Desktop body ≥16px, one focal point per screen — the tight mobile scale and an all-even grid both read "machine-made"
• One radius personality · one icon set · one shadow language — the coherence laws (§C0), the #1 fix for "looks AI-generated"
• Motion scoped by surface — a dashboard stays calm; a landing page gets the Cinematic tier (scroll-linked reveals, 3D hero, animated gradients — the Stripe/Linear playbook). Scroll-jacking is still banned everywhere (§43)

See all 74 rules → · the craft & coherence laws →

Every "help LLMs design better" project solves the wrong half of the problem. They feed the model more design data — brand palettes, font specs, shadow tokens, component libraries. I tried that first. Dumped Toss's entire design token JSON into my prompts. The output was still generic.

Then it hit me: a junior designer with Toss's palette still ships ugly dashboards. A senior designer with only grayscale ships something refined. The difference isn't what they have. It's what they know to do with it.

Design data is the paint. Design judgment is knowing where to put it.

See the before/after → — the same dashboard brief, generated generically vs. with the 74 rules applied. Every fix annotated with the rule behind it.

StyleSeed is a design engine — 74 visual rules, 48 components, a named motion system, and 19 slash commands that teach LLMs the judgment, not just the data:

"The most refined black isn't #000 — it's #2A2A2A"
"One accent color in the entire app. Everything else grayscale. Restraint is elegance."
"Shadows at 4% opacity. If you can see it, it's already too much."
"Numbers and units at 2:1 ratio. 48px number, 24px unit. Always."
"Never repeat the same section type twice. Alternate tall and compact for rhythm."
"Card/background separation matters more than any border."

Nobody writes these down. They're baked into years of experience — invisible to outsiders, invisible to LLMs. StyleSeed writes them down, organizes them into six categories (color discipline, spatial rhythm, information hierarchy, shadow/elevation, component variance, motion/feedback), and hands them to Claude as a single markdown file it reads automatically.

The rules are brand-agnostic — they don't reference specific colors, only semantic tokens. Which means the same rulebook works whether your app looks like Toss, Vercel, or your client's weird purple brand. Swap the skin, the judgment carries over.

    
Same engine, different skins. Built with Claude Code. Zero designer.

See full page

    

Claude Design generates UI fast — but it still picks #000 for text, reaches for six accent colors, and floats cards with no background separation. The missing piece isn't more templates. It's the 74 rules that tell the model when to use which pattern and why.

StyleSeed + Claude Design together:

1. Claude Design generates the layout and components (fast scaffolding)
2. StyleSeed's 74 rules refine the output (design judgment layer)
3. Brand skins make it look like your brand, not like "AI made this"

Drop DESIGN-LANGUAGE.md into your Claude Design workflow and the same model produces noticeably more refined output — without changing a single prompt.

The fastest paths are at the top — paste one prompt, or npx skills add bitjaru/styleseed. To wire StyleSeed into an existing project manually, use one of the options below.

New to this? Read top to bottom — every step matters. The most common mistake is expecting /ss-setup to work before the skills are copied into .claude/skills/. Do step 1 first.

Step 1 — Install the skills. Run this from your project's root folder (a terminal, not Claude Code):

# Download StyleSeed somewhere on your machine
git clone https://github.com/bitjaru/styleseed.git /tmp/styleseed

# Copy the slash-command skills into your project.
# NOTE: copy .claude/skills explicitly — `cp -r engine/*` skips hidden
# folders, which is why /ss-setup "doesn't exist" if you only do that.
mkdir -p .claude/skills
cp -r /tmp/styleseed/engine/.claude/skills/* .claude/skills/

Step 2 — Restart Claude Code (skills load at startup), open your project, and run:

/ss-setup

The wizard then walks you through:

1. App type (SaaS, e-commerce, fintech...)
2. Brand color or pick a skin (Toss, Stripe, Linear, Vercel, Notion...)
3. Or fetch any brand from awesome-design-md (58+ brands)
4. Font preference
5. Generates your first page automatically

Don't see the /ss-* commands? Confirm ls .claude/skills/ lists ss-setup, ss-page, etc., use the /ss- prefix (the old /ui-* names are gone), and restart Claude Code.

Already did step 1 above? These commands copy the rest of the engine into a typical src/-based React project. The source folder is engine/ (replace /tmp/styleseed with wherever you cloned it):

# Design reference + AI guide
mkdir -p .claude
cp /tmp/styleseed/engine/DESIGN-LANGUAGE.md .claude/DESIGN-LANGUAGE.md
cp /tmp/styleseed/engine/CLAUDE.md          ./CLAUDE.md

# Styles and components
mkdir -p src/styles src/components
cp -r /tmp/styleseed/engine/css/*        src/styles/
cp -r /tmp/styleseed/engine/components/*  src/components/

# Pick a skin — copy its theme.css alongside the other css files
cp /tmp/styleseed/skins/stripe/theme.css src/styles/theme.css

Refer to https://github.com/bitjaru/styleseed — read engine/CLAUDE.md 
and engine/DESIGN-LANGUAGE.md, then build a SaaS dashboard.
Use skins/stripe/theme.css for the color palette.

cp engine/.cursorrules your-project/.cursorrules

_{Want just some skills? npx skills add bitjaru/styleseed --skill ss-motion,ss-page cherry-picks.}

The honest reason: consistency comes from constraints. If you used a bare "apply StyleSeed" prompt (without the plan-mode + key-color + quality-gate steps the prompt above includes), the agent reads a summary once and improvises — so colors land at random and there's no key color. The reference demo (styleseed-demo.vercel.app) came out polished because it was built with the full rules in context and iterated with /ss-review — not one-shot. Recreate those conditions:

1. Plan first. In Claude Code press Shift+Tab to enter Plan Mode, then decide the design one step at a time, with full context, before any code is written. This is the single biggest fix.
2. Pin one key color. Give the agent a brand hex — or pick a skin (Linear / Stripe / Toss / …). The rule is one accent, everything else greyscale. No key color = the "random colors" look.
3. Point it at the full rules, not the summary: read https://styleseed-demo.vercel.app/llms-full.txt (the short llms.txt is an index, not the 74 rules).
4. Lock the decisions in a file. Run /ss-setup (or just ask the agent to "write a STYLESEED.md design lock"). It records your skin, key color, radius, and motion in STYLESEED.md at the repo root, and the rules tell the agent to obey it on every prompt — so the design stops being "different every time." This is the single strongest fix for inconsistency. (Also install CLAUDE.md / AGENTS.md / .cursorrules so the rules themselves are re-read every prompt.)
5. Be specific: "Build a dashboard in the Linear skin, one blue accent, Snap motion, following StyleSeed's rules" beats "build a dashboard."
6. Check & iterate. Run /ss-review or /ss-score, or tell it: "self-check coherence — one radius, one accent, real empty/loading/error states — and fix violations." If it drifts: "re-read CLAUDE.md and fix the coherence violations."

More constraints = less variance. Plan mode + a pinned key color + installed rules + a review pass is the difference between "looks generated" and "looks designed."

StyleSeed isn't only for new screens — it's the design counterpart to a code review for UI you already shipped. If an earlier build looks coherent but generic (default indigo, tiny desktop text, the same Lucide-icon-in-a-pale-chip on every card, no focal point):

1. /ss-score src/… — grades the screen 0–100 and names the exact "AI-made" tells (default accent, icon-chip cliché, sub-16px body on desktop, no focal point, missing states).
2. /ss-review src/… — the design code-review: applies the fixes (retint to your key color, drop the chips, bump the type scale, create a focal point), then re-score to ≥80.
3. /ss-update → Retrofit — no design lock yet? It writes a STYLESEED.md (mood, key color, font, surface) so the whole project stops drifting, then upgrades screen by screen.

The rules got stronger in v2.5.0, so a screen that passed the old bar may score lower now — that's the point. Fixing it is what makes it stop looking AI-made.

┌─────────────────────────────────────────────────┐
│  StyleSeed Engine (brand-agnostic)              │
│                                                 │
│  74 rules · 48 components · 19 skills · motion  │
│  Layout · Composition · Typography · UX · A11y  │
└──────────────────────┬──────────────────────────┘
                       │
              Pick a skin ↓
                       │
    ┌──────┬──────┬──────┬──────┬──────┬─────────┐
    │ Toss │Stripe│Linear│Vercel│Notion│ 58 more │
    │      │      │      │      │      │(awesome)│
    └──────┴──────┴──────┴──────┴──────┴─────────┘

Engine = how your app is structured (design intelligence)

• 74 visual design rules (layout, composition, rhythm, forbidden patterns)
• 48 React components (32 primitives + 16 patterns)
• A named motion system (5 seeds + a copy-paste keyword library)
• 15 Claude Code skills (setup, UI, motion, UX, accessibility)
• Works with ANY color palette

Skin = what your app looks like (visual identity)

• Just a theme.css file with color variables
• 7 built-in skins: Toss, Stripe, Linear, Notion, Raycast, Arc, Vercel
• 58+ more available from awesome-design-md
• Or create your own (change --brand and you're done)

Data repos (awesome-design-md) = paint colors. StyleSeed = the rulebook for where to put the paint. Use them together: they provide the skin, StyleSeed provides the brain. (Full comparison in Where StyleSeed fits.)

Flashy, named, copy-paste moves — live at /motion

Most AI-generated motion is the same default fade. StyleSeed gives motion a vocabulary — so you (and the LLM) can name a feel and get consistent, intentional animation across every page. Two layers:

1. Seeds = personality. Five named presets, each a spreadable framer-motion recipe in five contexts (entrance / exit / hover / press / layout):

import { spring } from "@engine/motion";

<motion.button {...spring.hover} {...spring.press}>Save</motion.button>

2. Keywords = distinctive moves. A library of copy-paste named motions behind one handle — toggle-flip, toggle-curtain, reveal-blur, pop-in, tilt-3d, magnetic, glow-pulse, confetti-pop, shimmer, and more. Say the keyword while vibe coding (or run /ss-motion toggle-flip) and the same recipe lands in your code.

▶ Preview & copy every motion at the live gallery →  ·  Vibe-code your own → the motion guide

3. Motion is scoped by surface — calm apps, cinematic landing pages. This is the part most rule-sets get wrong: they ban scroll animation everywhere (so your marketing page ends up flat), or allow it everywhere (so your dashboard scroll-jacks). StyleSeed splits it:

The line StyleSeed draws: scroll-linked (native scroll drives it, you stay in control) is encouraged on brand pages; scroll-jacking (hijacking scroll speed, trapping you) is banned everywhere. The Cinematic tier keeps its guardrails — 60fps (transform/opacity only), never blocks the first read or the CTA, and prefers-reduced-motion always leaves a complete static page. So you can build a Stripe-grade landing page and a calm dashboard from the same engine, each with the right restraint. _{(Rules: DESIGN-LANGUAGE §43 · PAGE-TYPES → Landing)}

All seeds auto-respect prefers-reduced-motion, and the /ss-motion skill pulls every recipe from one source of truth — so motion stays consistent no matter who (or what) writes the code.

engine/
├── CLAUDE.md                 # AI reads this automatically
├── DESIGN-LANGUAGE.md        # 74 visual design rules (brand-agnostic)
├── .claude/skills/           # 19 slash commands (/ss-*)
│   ├── ss-setup/             #   Interactive setup wizard
│   ├── ss-page/              #   Scaffold pages
│   ├── ss-component/         #   Generate components
│   ├── ss-pattern/           #   Compose layouts
│   ├── ss-motion/            #   Apply named motion (seeds + keywords)
│   ├── ss-review/            #   Design compliance check
│   ├── ss-tokens/            #   Manage tokens
│   ├── ss-a11y/              #   Accessibility audit
│   ├── ss-lint/              #   Quick violation scan
│   ├── ss-score/             #   Score UI 0-100 + fix list
│   ├── ss-update/            #   Pull latest engine
│   ├── ss-flow/              #   Design user flows
│   ├── ss-audit/             #   UX heuristic evaluation
│   ├── ss-copy/              #   Generate microcopy
│   └── ss-feedback/          #   Add loading/error/empty states
├── motion/                   # 5 motion seeds + keyword library
├── components/
│   ├── ui/                   # 32 primitives (shadcn/ui + motion)
│   └── patterns/             # 16 dashboard patterns
├── css/                      # base.css, fonts.css, index.css
├── tokens/                   # 6 JSON token files
├── utils/                    # Formatting utilities
├── icons/                    # Custom SVG icon library
└── scaffold/                 # Vite 6 + React 18 starter

/ss-setup                    # Pick skin, configure project
/ss-page Dashboard           # Scaffold main page
/ss-copy "dashboard"         # Generate all microcopy
/ss-feedback src/Dashboard   # Add loading/error states
/ss-audit src/Dashboard      # Check UX quality
/ss-lint src/Dashboard       # Quick violation scan
/ss-review src/Dashboard     # Deep design compliance check
/ss-update                   # Pull latest engine updates

New project:

Refer to https://github.com/bitjaru/styleseed — read engine/CLAUDE.md 
and engine/DESIGN-LANGUAGE.md. Use skins/stripe/theme.css for colors.
Build a SaaS dashboard with revenue, users, and activity.

Add a page (engine already in project):

Follow CLAUDE.md and DESIGN-LANGUAGE.md rules.
Create a settings page with profile, notifications, and danger zone.
Run /ss-review when done.

Improve existing page:

Refactor src/Dashboard.tsx to follow DESIGN-LANGUAGE.md.
Check visual rhythm (rule 61) and KPI variation (rule 62).

Update engine:

/ss-update

React 18 · TypeScript · Tailwind CSS v4 · Radix UI · Vite 6 · Lucide Icons · CVA

TL;DR: shadcn/ui gives you components. Tailwind UI gives you templates. StyleSeed gives you the design judgment that makes AI output stop looking like AI output.

Q: Why does Claude Code / Cursor generate ugly UI? Because LLMs optimize for functional correctness, not visual refinement. They'll pick #000 for text, py-4 for spacing, text-xl for everything — all technically valid, all amateur. StyleSeed gives them the rules professional designers use.

Q: Is this a shadcn/ui replacement? No — it's built on top of shadcn/ui patterns. StyleSeed components use the same Radix primitives and CVA conventions. Think of it as shadcn/ui + design judgment + AI-tool integration.

Q: Does it work with Cursor too? Yes. The 74 design rules live in a .cursorrules file and CLAUDE.md. Cursor reads them automatically.

Q: How is this different from awesome-design-md? awesome-design-md gives you brand DESIGN.md files (what). StyleSeed gives you the engine that turns any brand into a working app (how). They pair well.

Q: Can I use it for a non-fintech app? Yes. The engine is brand-agnostic. Pick any skin, swap the brand color, ship.

Full docs in the Wiki — design rules reference, composition recipes, chart guides, skills reference.

StyleSeed is a living judgment framework — the rules aren't carved in stone. If you use it and find a pattern that reliably makes UI better, teach it to everyone's AI by proposing it as a rule.

A good rule is a decision + the reason it works, written so a model can apply it — not an opinion.

**Rule:** Numbers are 2:1 with their unit (a 48px value over a 24px unit).
**Why it works:** The eye locks onto magnitude first; equal sizes flatten the value into noise.
**Source:** Refactoring UI.

Open a "Propose a design rule" issue, or PR it into engine/DESIGN-LANGUAGE.md (visual/layout) or engine/VISUAL-CRAFT.md (craft & coherence). The judgment compounds as the community adds to it.

Just a theme.css + skin.json:

mkdir skins/your-brand
cp skins/toss/theme.css skins/your-brand/theme.css   # copy a skin as a starting point
# Change the --brand color and other values

Better rules → better AI output: more specific design rules, new pattern components, accessibility improvements, new AI skills.

See CONTRIBUTING.md for the full rule format and quality checklist.

Already using StyleSeed? Quick update (always safe):

# Pull latest
cd styleseed && git pull

# Update design rules + skills (safe — no project-specific content)
cp styleseed/engine/DESIGN-LANGUAGE.md your-project/.claude/DESIGN-LANGUAGE.md
cp -r styleseed/engine/.claude/skills/ your-project/.claude/skills/

Don't overwrite: your theme.css (brand colors), CLAUDE.md (if project-specific), or customized components.

Full guide: engine/UPDATE.md

Get notified: Click Watch → Custom → Releases on this repo.

MIT

• Design language inspired by Toss
• Components based on shadcn/ui
• Brand skins sourced from awesome-design-md
• UX principles from Laws of UX and Nielsen Norman Group