Beautiful GUI Design

Treat the screen as a designed surface, not a dump of controls: hierarchy, color, type, motion, and accessibility are load-bearing, and every choice must survive light/dark mode, small and large viewports, keyboard and screen-reader use, and the conventions of the platform it ships on.

When to Use

• Designing or reviewing a web app, marketing page, dashboard, or settings/onboarding flow.
• Building a desktop GUI (Electron/Tauri) or a native app (SwiftUI/AppKit, Jetpack Compose, WinUI).
• Establishing a design system: semantic color tokens, a type scale, spacing, elevation, component states.
• Adding light/dark themes, fixing contrast/accessibility failures, or making a layout responsive.
• Choosing a component approach (headless primitives vs. styled kit) or a design-to-code tool.

NOT for

• Terminal/CLI output, TUIs, prompts, or ANSI rendering. Use beautiful-cli-design.
• API response schemas, wire formats, or machine-only output contracts.
• Backend architecture, data modeling, or non-visual logic.
• Brand strategy / copywriting (this is the visual + interaction layer).

Decision Points

flowchart TD
  A[GUI design task] --> B{Output target?}
  B -->|Web| C{Component adapts to its container or the page?}
  C -->|Its container| C1[Container queries + fluid type]
  C -->|The page| C2[Mobile-first breakpoints]
  B -->|Desktop Electron/Tauri| D[Web tech, but adopt the host OS idioms]
  B -->|Native iOS/macOS| E[SwiftUI + SF Symbols + Apple HIG]
  B -->|Native Android| F[Compose + Material 3 + Material icons]
  C1 --> G{Need ship-fast or full control?}
  C2 --> G
  D --> G
  G -->|Ship fast| H[Styled kit: shadcn/ui on Radix]
  G -->|Full control / cross-platform looks| I[Headless primitives: Radix/Headless UI + own styling]
  H --> J[Layer the system: tokens -> components -> a11y -> motion]
  I --> J
  E --> J
  F --> J

Route first:

• Tokens before components, components before screens. A screen built on ad-hoc values can't be themed or kept consistent. Build the three-tier token model (primitive → semantic → component) first. See references/06-component-systems-tokens-and-platform-idioms.md.
• Headless primitives (Radix/Headless UI) when you need full visual control or different looks per platform; styled kits (shadcn/ui) when you want 80% shipped with accessibility already handled. Never hand-roll an interactive control without the ARIA/keyboard logic a primitive gives you.
• Container queries when a component appears at multiple widths (sidebar vs. grid); breakpoints for page-level layout.
• Native means native. A web look shipped on iOS/Android reads as a web app. Adopt the platform's icons, spacing, type, and controls.

Visual System Rules

• Spacing is a system, not vibes. Use an 8pt grid (4pt for micro-adjustments). One base per project. references/01.
• Hierarchy needs contrast, not just color. Distinguish tiers by ≥1.5–2× size plus weight/position — never color alone. references/01.
• Color is semantic tokens, never raw hex in components. Build a perceptually-uniform (OKLCH) ramp; derive light/dark and every state from it. references/02.
• Type: rem not px, a modular scale, body ≥ 14px (0.875rem). 45–75ch measure, role-based line-height. Honor OS Dynamic Type; never lock zoom. references/03.
• Motion is communication, not decoration. 100–300ms, ease-out to enter / ease-in to exit, animate only transform/opacity, always honor prefers-reduced-motion. references/04.
• Accessibility is a design input, not a retrofit. Semantic HTML/native controls first, visible focus always, 4.5:1 body contrast, 44/48pt touch targets, keyboard + screen-reader passes. references/05.
• Icons are an icon system (SF Symbols / Lucide / Heroicons), never emoji. Emoji as UI icons reads as cheap and renders inconsistently.

Failure Modes

Anti-Pattern: "Rainbow Vomit"

Symptom: Many unrelated colors; states (hover/error/focus) are indistinguishable from intent (primary/info).
Detection rule: Count unique colors in a 400×400px screenshot — more than ~8 is a smell.
Fix: One primary + one accent + semantic status colors; derive hover/active/disabled by lightness offset. references/02.

Anti-Pattern: "Invisible in Light Mode" (or Dark)

Symptom: Looks fine in one theme, unreadable in the other (light text on light, low-contrast accents).
Detection rule: Hardcoded theme colors; contrast checker reports < 4.5:1 (text) or < 3:1 (UI) in either mode. scripts/gui_design_audit.mjs flags low-text-contrast (critical) when textContrastMinRatio < 4.5, and missing-light-dark (high) when lightAndDark is false.
Fix: Semantic tokens with real light AND dark values (not an inversion); verify both with a contrast tool. references/02.

Anti-Pattern: "Tiny Type / Locked Zoom"

Symptom: Body/caption text below 14px; user-scalable=no or maximum-scale<2; ignores OS text size.
Detection rule: Grep for font-size: 0.[0-7]…, Tailwind text-xs on prose, user-scalable=no. scripts/gui_design_audit.mjs flags tiny-body-font (critical) when minBodyFontPx < 14.
Fix: rem-based scale, ≥14px body, honor Dynamic Type, never disable zoom. references/03, references/05.

Anti-Pattern: "Decorative Motion / Layout Thrash"

Symptom: Animations on width/height/top/left, parallax, >300ms repeated transitions; janky on mobile.
Detection rule: DevTools Performance shows tall Layout/Recalc bars during animation; no prefers-reduced-motion path.
Fix: Animate transform/opacity only; tokenize durations/easing; honor reduced-motion. references/04.

Anti-Pattern: "Web Look on Native"

Symptom: Material ripples on iOS, 4pt corners and emoji icons, centered controls that fight the HIG.
Detection rule: Side-by-side with a first-party app (Settings, Messages) — corners/spacing/icons/controls differ.
Fix: Use the platform's primitives, icon set, spacing, and type. references/06.

Anti-Pattern: "Magic Numbers in Components"

Symptom: padding: 13px, one-off hex, hand-picked hover colors scattered through component files.
Detection rule: Grep components for numeric literals and #[0-9a-f]{6} — every hit is un-tokenized. scripts/gui_design_audit.mjs flags no-semantic-tokens (critical) when semanticTokensUsed is false, and ad-hoc-spacing (high) when spacingScale is "ad-hoc".
Fix: Three-tier tokens; components reference semantic tokens only. references/06.

Anti-Pattern: "Stateless / Inaccessible Controls"

Symptom: A control with only default + click; no focus ring, no disabled/loading/error, <div>-as-button.
Detection rule: Tab through the UI — focus vanishes; render the control in all states — most are missing. scripts/gui_design_audit.mjs flags no-interactive-states (critical) when interactiveStatesDefined is false.
Fix: Full state machine (default/hover/active/focus/disabled/loading) on a semantic element or headless primitive. references/05, references/06.

Anti-Pattern: "Cramped Touch Targets"

Symptom: Buttons/icons sized to their visual glyph (e.g. a 20×20px icon button) with no invisible hit-area padding; taps miss or double-fire on mobile.
Detection rule: Rendered hit area (including padding) measures below 44×44pt (iOS) / 48dp (Android) / the 24px WCAG 2.5.8 floor, with tight surrounding spacing. scripts/gui_design_audit.mjs flags touch-target-below-minimum (high) when touchTargetMinPx < 44.
Fix: Pad the interactive element — not just the glyph — to at least the platform minimum, and space adjacent targets so they don't crowd. references/05.

Anti-Pattern: "Design-by-Committee Type System"

Symptom: Every screen introduces a new font weight or one-off size; the type scale has ballooned past a handful of steps and reads inconsistent.
Detection rule: More than ~3 font weights or more than ~8 distinct font sizes in the shipped system. scripts/gui_design_audit.mjs flags too-many-font-weights (medium) when fontWeightsCount > 3, and too-many-font-sizes (medium) when fontSizesCount > 8.
Fix: Collapse to a modular scale (~6–8 sizes) and 2–3 weights (regular/medium/bold); every new size must justify itself against the scale. references/03.

Worked Example: A Button, Done Right

Before — hardcoded, themeless, inaccessible:

<button style={{ background: '#0066FF', color: '#fff', padding: '13px', borderRadius: 4 }}>Save</button>

Problems: raw hex (no theme), magic padding, no hover/active/focus/disabled, white text may fail contrast, no dark mode.

After — tokens + states + a11y:

.btn-primary {
  background: var(--color-primary);
  color: var(--color-text-on-primary);
  padding: var(--space-2) var(--space-4);      /* 8pt grid */
  border-radius: var(--radius-md);
  font-size: 1rem;                              /* ≥14px */
  transition: background-color 150ms cubic-bezier(0,0,.2,1);  /* ease-out */
}
.btn-primary:hover    { background: var(--color-primary-hover); }   /* −10% L */
.btn-primary:active   { background: var(--color-primary-active); transform: scale(.98); }
.btn-primary:focus-visible { outline: 3px solid var(--color-focus-ring); outline-offset: 2px; }
.btn-primary:disabled { background: var(--color-surface-subtle); color: var(--color-text-disabled); cursor: not-allowed; }
@media (prefers-reduced-motion: reduce) { .btn-primary { transition: none; } }

Why it works: a semantic <button> (keyboard + SR for free), tokens that flip cleanly for dark mode, every state defined, contrast guaranteed by token design, motion that respects the user. The same tokens render natively via SF Symbols/SwiftUI on iOS and Compose on Android (references/06).

Quality Gates

• Spacing on an 8pt system; one base; no magic numbers in components.
• Hierarchy reads when squinting — focal point obvious via size/weight/position, not color alone.
• Color is semantic tokens; light AND dark both designed and contrast-verified (4.5:1 text, 3:1 UI).
• Type in rem, body ≥14px, modular scale, 45–75ch measure; OS text-size honored; zoom never locked.
• Every interactive element has default/hover/active/focus-visible/disabled (+ loading where async).
• Keyboard pass: full operability, visible focus on every stop, modals trap + restore focus.
• Screen-reader pass: semantic elements/labels; ARIA only where needed and correct.
• Motion: transform/opacity only, tokenized duration/easing, prefers-reduced-motion honored.
• Touch targets ≥44×44pt (iOS) / 48dp (Android) / ≥24px (WCAG), adequately spaced.
• Icons from an icon system (SF Symbols/Lucide/Heroicons), never emoji-as-icon.
• Native builds use native idioms (controls, icons, spacing, type) — no web look shipped on native.
• Tokens flow to all targets from one source (web CSS vars, iOS Swift, Android Kotlin).

Deterministic Audit

Once a design is measurable as data — one spec per surface, per schemas/gui-spec.schema.json — run it through scripts/gui_design_audit.mjs to check it against the Quality Gates above before calling the work done:

node skills/beautiful-gui-design/scripts/gui_design_audit.mjs --input skills/beautiful-gui-design/examples/sample-input.json

auditGuiDesign(spec) returns { pass, score, findings, recommendations }, flagging low text contrast, missing light/dark, a too-small body font, an un-tokenized (raw hex/px) system, ad-hoc spacing off the 8pt/4pt grid, too many font weights/sizes, undersized touch targets, and interactive elements missing their full state machine. It audits the measured spec, not the rendered UI — the Keyboard pass, Screen-reader pass, and "built and run" checks above still have to happen by hand.

Fork Guidance

Fork when the work has distinct lanes owned by different actors:

• Visual-system lane: hierarchy, color, type, spacing, elevation (references/01–03).
• Interaction lane: component states, motion, micro-interactions (references/04, 06).
• Accessibility lane: keyboard, screen reader, contrast, targets, reduced-motion (references/05).
• Platform lane: native idioms, token flow, responsive/adaptive (references/06).

Keep final visual-language decisions in the parent so one actor owns coherence.

Reference Map

• references/01-visual-hierarchy-layout-spacing.md — Gestalt, the 8pt/4pt system, layout grids and safe areas, focal point, density vs. whitespace, elevation, layout archetypes.
• references/02-color-and-theming.md — semantic tokens, OKLCH ramps, light/dark done right, WCAG contrast math, state colors, data-viz vs. chrome, theming architecture.
• references/03-typography.md — modular scales, rem, line-height/measure, pairing, variable fonts, web-font loading, fluid type, Dynamic Type, the 14px floor.
• references/04-motion-and-microinteractions.md — duration/easing tokens, spring vs. tween, purposeful motion, the compositor budget, honest progress, reduced-motion.
• references/05-accessibility-and-inclusive-design.md — WCAG 2.2 AA, semantic-first, keyboard + focus management, targets, live regions, forms, testing workflow.
• references/06-component-systems-tokens-and-platform-idioms.md — three-tier tokens, component anatomy/states, headless vs. styled, token flow web↔native, responsive/adaptive, iOS/macOS/Android/Windows idioms, design-to-code tooling.

Machine-checkable governance layer, for turning a design brief into an auditable spec:

• schemas/gui-spec.schema.json — the JSON shape of a GUI design spec (contrast, type, tokens, spacing, targets, states).
• scripts/gui_design_audit.mjs — auditGuiDesign(spec), a deterministic check of a spec against the Quality Gates above.
• examples/sample-input.json — a complete, passing GUI spec.
• examples/expected-output.md — a failing spec audited, then the fix walkthrough to a passing one.
• templates/output-template.md — a fill-in template for the visual-design-system-and-layout deliverable.
• agents/openai.yaml — a subagent descriptor for delegated GUI design work.

Layout QA gate (mechanical — run before shipping)

Before calling any rendered page, artifact, dashboard, deck, or component done,
run the mechanical overflow/collision checker. It renders the page headlessly and
flags text-vs-text collisions, clipped/ellipsis-truncated elements, text escaping
its container, and horizontal page scroll — the visual defects a screenshot hides
and that only appear at a specific width or in one theme.

Resolve layout-overflow-guard from the active skill catalog before running it.
The command below shows the standard Claude install path; use the path reported
by your harness. If the skill is absent, install or sync it instead of skipping
this gate.

python3 ~/.claude/skills/layout-overflow-guard/scripts/check_layout.py <file-or-url> \
  --widths 1280,1100,860,720,390 --themes light,dark

You do not need to read check_layout.py — invoke it with the Bash tool and
act on its report and exit code (non-zero = a defect). The script's source never
enters your context; only its findings do. Drive it to zero violations across
every width and both themes before you ship. Full detail: the
layout-overflow-guard skill.

Skill Bundle Index

Every file in this skill, and when to open it. Auto-generated; run scripts/index_references.py --fix.

root

• `CHANGELOG.md` — Beautiful GUI Design — Changelog — - Upgraded to the agentic-family standard: license, block-style provenance (first-party/port-daddy), pairs-with (gpui-rust-console, ru
• `README.md` — Beautiful GUI Design — Treat the screen as a designed surface, not a dump of controls: hierarchy, color, type, motion, and accessibility are load-bearing, and ever

agents/

• `agents/openai.yaml` — openai (data/schema)

examples/

• `examples/expected-output.md` — Example Output: Beautiful GUI Design — Scenario: the "Before" button from SKILL.md's Worked Example, generalized to a whole screen — hardcoded hex, magic padding, no dark theme,
• `examples/sample-input.json` — sample input (data/schema)

references/

• `references/01-visual-hierarchy-layout-spacing.md` — Visual Hierarchy, Layout & Spacing — **Visual hierarchy is the art of making some elements more prominent than others through spatial relationships, sizing, color, and alignment
• `references/02-color-and-theming.md` — Color & Theming: Semantic Tokens, Accessible Contrast, and Multimode Systems — Raw hex colors in components are the root of evil.
• `references/03-typography.md` — Typography Systems — A modular type scale anchors all typographic decisions.
• `references/04-motion-and-microinteractions.md` — Motion & Micro-Interactions Reference — Motion is communication—feedback on state, guidance through hierarchy, reassurance during waits, and affordance signaling on interactive ele
• `references/05-accessibility-and-inclusive-design.md` — Accessibility & Inclusive Design: WCAG 2.2 AA Essentials — True accessibility is a design discipline, not a retrofit.
• `references/06-component-systems-tokens-and-platform-idioms.md` — Component Systems, Design Tokens & Platform-Native Idioms — A professional design system bridges the gap between tokens (semantic units of visual design), components (reusable building blocks

schemas/

• `schemas/gui-spec.schema.json` — gui spec.schema (data/schema)

scripts/

• `scripts/gui_design_audit.mjs`

templates/

• `templates/output-template.md` — Visual Design System & Layout Brief — Fill in every section before handing this off for implementation.