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
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 unless custom values already exist or are explicitly requested
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 (
Base UI
,
React Aria
,
Radix
)
MUST use the project’s existing component primitives first
NEVER mix primitive systems within the same interaction surface
SHOULD prefer
Base UI
for new primitives if compatible with the stack
MUST add an
aria-label
to icon-only buttons
NEVER rebuild keyboard or focus behavior by hand unless explicitly requested
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
SHOULD 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-
)
SHOULD use
size-
for square elements instead of
w-
+
h-*
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