Baseline UI

Enforces an opinionated UI baseline to prevent AI-generated interface slop.

How to use

/baseline-ui

Apply these constraints to any UI work in this conversation.

/baseline-ui <file>

Review the file against all constraints below and output:

• violations (quote the exact line/snippet)

• why it matters (1 short sentence)

• a concrete fix (code-level suggestion)

Stack

• MUST use Tailwind CSS defaults (spacing, radius, shadows) before custom values

• MUST use motion/react (formerly framer-motion ) when JavaScript animation is required

• SHOULD use tw-animate-css for entrance and micro-animations in Tailwind CSS

• MUST use cn utility (clsx

• tailwind-merge ) for class logic

Components

• MUST use accessible component primitives for anything with keyboard or focus behavior (Radix )

• MUST use the project’s existing component primitives first

• NEVER mix primitive systems within the same interaction surface

• MUST add an aria-label to icon-only buttons

• NEVER rebuild keyboard or focus behavior by hand unless explicitly requested

• MUST use isLoading prop on the Button component when indicating loading state

• NEVER use ml-x or mr-x when styling an icon inside a button, since spacing will be given to it automatically

• NEVER explicitly set border color to border-border since this is the default border color

Interaction

• MUST use an AlertDialog for destructive or irreversible actions

• SHOULD use structural skeletons for loading states

• NEVER use h-screen , use h-dvh

• MUST respect safe-area-inset for fixed elements

• MUST show errors next to where the action happens

• NEVER block paste in input or textarea elements

Animation

• NEVER add animation unless it is explicitly requested

• MUST animate only compositor props (transform , opacity )

• NEVER animate layout properties (width , height , top , left , margin , padding )

• SHOULD avoid animating paint properties (background , color ) except for small, local UI (text, icons)

• SHOULD use ease-out on entrance

• NEVER exceed 200ms for interaction feedback

• MUST pause looping animations when off-screen

• MUST respect prefers-reduced-motion

• NEVER introduce custom easing curves unless explicitly requested

• SHOULD avoid animating large images or full-screen surfaces

Typography

• MUST use text-balance for headings and text-pretty for body/paragraphs

• MUST use tabular-nums for data

• SHOULD use truncate or line-clamp for dense UI

• NEVER modify letter-spacing (tracking- ) unless explicitly requested

Layout

• MUST use a fixed z-index scale (no arbitrary z-x )

• SHOULD use size-x for square elements instead of w-x

• h-x

• SHOULD use gap-* for spacing between elements instead of space-x-* or space-y-* (with appropriate flex and flex-direction classes)

Performance

• NEVER animate large blur() or backdrop-filter surfaces

• NEVER apply will-change outside an active animation

• NEVER use useEffect for anything that can be expressed as render logic

Design

• NEVER use gradients unless explicitly requested

• NEVER use purple or multicolor gradients

• NEVER use glow effects as primary affordances

• SHOULD use Tailwind CSS default shadow scale unless explicitly requested

• MUST give empty states one clear next action

• SHOULD limit accent color usage to one per view

• SHOULD use existing theme or Tailwind CSS color tokens before introducing new ones