Use whenever you spec, cast, or build frontend/UI work — a page, component, dashboard, marketing site, app screen, or "make it look good." Encodes the house aesthetic and a Tailwind-first, source-before-hand-roll workflow (21st.dev → shadcn/ui → build). Invoke it before writing a frontend brief and hand it to any worker implementing UI work.
Use whenever you spec, cast, or build frontend/UI work — a page, component, dashboard, marketing site, app screen, or "make it look good." Encodes the house aesthetic and a Tailwind-first, source-before-hand-roll workflow (21st.dev → shadcn/ui → build). Invoke it before writing a frontend brief and hand it to any worker implementing UI work.
ui-designer
This is the house style. Load it every time UI is on the table — when you brief frontend work,
when you write the prompt, and (as a worker) before you touch a single component.
The point is that Beckett's UI has a consistent, opinionated look instead of being reinvented,
blandly, one build at a time. Taste is a default here, not a coin flip.
Anything visual is an Opus seat (see the frontend row in [[concierge]] — claude-opus-5 @
high). This skill is what that seat implements against.
The one rule: source before you hand-roll
Do not build a button, dialog, dropdown, toast, table, or command palette from scratch.
Someone already built it better. The default first move on any component is to pull a base:
Check 21st.dev first. It's a community registry of shadcn/Tailwind
React components you copy-paste. Search the pattern ("pricing table", "bento grid", "auth
card", "animated navbar"). Grab the closest match as a starting skeleton.
Fall back to shadcn/ui. For the canonical primitives (button, dialog, input, select,
dropdown, tabs, sheet, command, sonner toasts) use the registry: npx shadcn@latest add <component>. These are unstyled-by-default Radix primitives — accessible out of the box,
yours to theme.
Then restyle to the house tokens. Never ship a component stock. Retheme it to our color
tokens, spacing, radius, and motion (below). Stock shadcn looks like stock shadcn; that's the
tell of a UI nobody cared about.
Hand-roll only when nothing fits — a genuinely bespoke layout, a custom viz, a one-off
interaction. Even then, steal the structure (Radix primitives for behavior, our tokens for
looks). Reinventing a focus-trap or a combobox from zero is how you ship a11y bugs.
Hand-rolling is the exception you justify, not the default you reach for.
The house aesthetic — a real POV
Confident minimalism with one point of personality. Think Linear / Vercel / Stripe: calm
neutral canvas, generous whitespace, tight typography, sharp contrast, and exactly one accent
doing the talking. Restraint reads as expensive; decoration reads as cheap. When in doubt, remove.
Non-negotiables:
Whitespace is the design. Crowded is the #1 amateur tell. Give things room; let sections
breathe. Padding is not wasted space.
One accent, used sparingly. A single brand color for primary actions and focus. Everything
else is neutral. A rainbow UI has no hierarchy.
Depth from contrast and subtle borders, not heavy shadows. Flat surfaces separated by a
hairline border (border-border) and a half-step background shift beat drop-shadow soup.
Sharp, consistent geometry. One radius token everywhere (rounded-lg / rounded-xl as the
house default — pick one per project and hold it). Mismatched corner radii look broken.
Dark mode is not an afterthought. Build with tokens so it works from day one.
If a screen looks like a Bootstrap admin template from 2016, you've failed the aesthetic.
The stack — Tailwind-first, always
React + Tailwind CSS. Utility classes in the markup; no bespoke CSS files, no CSS-in-JS
runtime. Tailwind's scale is the spacing/type/color system — use it, don't fight it.
shadcn/ui as the component substrate (Radix behavior + Tailwind styling, copied into the
repo so it's ours to edit). 21st.dev for richer/marketing patterns on top.
lucide-react for icons. One icon set, consistent stroke weight. Never mix icon libraries.
Framer Motion for orchestrated/gesture motion; plain transition-* utilities for simple
hover/focus. Don't pull Framer for a color fade.
Geist or Inter for sans; a real mono (Geist Mono / JetBrains Mono) for code/numbers.
cn() (clsx + tailwind-merge) for conditional classes — the shadcn convention.
Don't introduce a second UI kit (no MUI/Chakra/AntD alongside this). One system.
Layout & spacing — a 4px grid
4px base unit. Only use Tailwind's scale steps: 1 2 3 4 6 8 12 16 24 (= 4–96px). Never
hand-type arbitrary values like p-[13px]; snap to the grid.
8px rhythm for real spacing. Gaps between elements: gap-2/gap-4; between sections:
py-12/py-16/py-24. Keep vertical rhythm consistent down a page.
Contain content. Center a max-w-6xl (~1152px) or max-w-7xl for apps, max-w-2xl/3xl
for reading/forms. Full-bleed text is unreadable. Generous gutters (px-4 sm:px-6 lg:px-8).
Flexbox and CSS Grid only. No absolute positioning for layout (fine for badges/overlays).
flex for one axis, grid for two. gap-* over margins for spacing between siblings.
Mobile-first. Base styles are the phone; layer sm:/md:/lg: up. Design the small
screen first, then let it expand — never the reverse.
Typography — hierarchy by weight, not size soup
One typeface family (plus a mono for code/data). Two at most.
Scale:text-sm (14, secondary/meta) · text-base (16, body — the floor for reading) ·
text-lg/xl (lead) · text-2xl–text-4xl (headings) · text-5xl+ (hero only).
Two, maybe three sizes per screen. Establish hierarchy with weight (font-medium /
font-semibold) and color (text-foreground vs text-muted-foreground), not five sizes.
Tighten headings:tracking-tight and leading-tight/leading-none on large text; roomy
leading-relaxed (~1.6) on body. Big type with default tracking looks loose and cheap.
Measure: cap body line length around 65–75ch (max-w-prose). Walls of full-width text lose
the reader.
Numbers:tabular-nums for anything in a table or that ticks/updates, so digits don't jitter.
Color & theming — tokens, not hex
Use the shadcn CSS-variable token system. Style against semantic tokens, never raw palette:
bg-background / text-foreground — the base canvas and ink.
bg-card / bg-muted — raised and recessed surfaces.
text-muted-foreground — secondary text (labels, captions, meta).
border-border / ring-ring — hairlines and focus rings.
bg-primary text-primary-foreground — the one accent, for primary actions.
destructive for danger. Semantic states (success/warning) as named tokens, not inline greens.
Rules:
Neutral base + one accent. Ground on a neutral ramp (zinc is the house default; slate/
stone are fine — pick one). Reserve saturated color for the accent and semantic states.
~60/30/10: ~60% background/neutral, ~30% surfaces/secondary, ~10% accent. If accent is
everywhere, it's nowhere.
Define both themes via :root and .dark token blocks. If you write a raw hex in a
component, you've broken theming — go add a token.
Contrast is a constraint, not a nicety — body text ≥ 4.5:1, large text/UI ≥ 3:1.
Motion & interaction — purposeful and fast
Fast and subtle.150–250ms, ease-out for enters, ease-in for exits. Anything slower
than ~300ms feels laggy. No bouncy 600ms springs on a menu.
Every interactive element has states: rest, hover:, focus-visible:, active:, and
disabled:. A button with no hover/press feedback feels broken even when it works.
Animate transform and opacity, not width/top/height (those thrash layout). Slide/fade/
scale, not reflow.
Motion earns its place: reveal state, guide the eye, soften a transition. Decorative
animation that says nothing is noise — cut it.
prefers-reduced-motion: reduce → kill non-essential motion. Framer's useReducedMotion or
a motion-reduce: variant. This is a baseline, not optional.
Accessibility — the floor you never go below
Semantic HTML. Real <button> for actions, <a> for navigation, one <h1>, ordered
headings. Never a clickable <div>.
Visible focus, always.focus-visible:ring-2 ring-ring. Never outline-none without a
replacement ring — you're stranding keyboard users.
Keyboard-complete. Everything reachable and operable by Tab/Enter/Esc/arrows. (Radix/shadcn
gives you this free — another reason to source, not hand-roll.)
Labels & alt. Every input has a <label> (or aria-label); every meaningful image has
alt; icon-only buttons get an accessible name.
Hit targets ≥ 44×44px on touch. Don't ship 20px tap zones.
Contrast AA (see color). Don't encode meaning by color alone — pair with icon/text.
What good looks like — the rubric (self-check before you call it done)
Read your own UI against this. If you can't check a box, fix it, don't ship it.
Sourced, not hand-rolled — primitives came from shadcn/21st.dev and were rethemed; no
reinvented dialogs/comboboxes; no stock-shadcn tell.
Responsive — designed mobile-first; no horizontal scroll or overflow at 375px; scales up
cleanly.
Consistent — one radius, one icon set, one type family, aligned spacing. No stray
one-offs.
Intentional — looks like someone with taste made a decision, not a framework default.
How to apply it — implementing UI work
Open with this skill. Re-read the aesthetic and rubric before you write code so the
defaults are loaded.
Decompose into components, then for each: 21st.dev → shadcn/ui → hand-roll (the one
rule). Add primitives via npx shadcn@latest add ….
Set the tokens first. Establish the color tokens (:root + .dark), radius, and font in
the theme layer before building screens — so everything inherits the house look, not the
default.
Build mobile-first, layout with flex/grid on the 4px grid, type on the scale, color on
tokens.
Wire states and motion — hover/focus/active/disabled and fast, purposeful transitions;
honor reduced-motion.
Run the rubric on yourself. No cold reviewer can catch taste — it reads a diff, it never
sees the page — so you are the gate that matters. Walk every box; fix misses.
Show it. Deploy the running result to a subdomain ([[deploy]]) or attach a screenshot so a
human can judge by eye — the only real test of visual work. Need a raster asset (logo, hero,
illustration)? Generate it ([[image]]), don't fake it with CSS.
Plugging into a frontend prompt
When you (concierge) brief frontend work, name this skill in the prompt so the worker loads the
same taste you did. A frontend prompt should read like:
Invoke the ui-designer skill. Build the pricing page. Check 21st.dev for a pricing-table
base and shadcn/ui for the primitives (button, card, toggle) before hand-rolling anything;
retheme to our tokens. House aesthetic: confident minimalism, one accent, generous whitespace,
dark-mode-from-tokens. Tailwind + shadcn only. Self-check against the ui-designer rubric before
done (sourced/breathes/hierarchy/token-pure/alive/accessible/responsive). Cast:
{"implement":{"harness":"claude","model":"claude-opus-5","effort":"medium"}}.
That one paragraph turns "make a pricing page" into a brief with a design POV baked in — which is
the whole point of having a house style. See the frontend seat and cast table in [[concierge]].
