Stripe UI Skills

Opinionated constraints for building Stripe-style interfaces with AI agents.

When to Apply

Reference these guidelines when:

• Building light-mode interfaces

• Creating Stripe-inspired design systems

• Implementing UIs with Inter font and 4px grid

Colors

• SHOULD use light backgrounds for primary surfaces

• MUST use #F2F6F9 as page background (surface-base )

• MUST use #517BDF for primary actions and focus states (accent )

• SHOULD reduce color palette (currently 30 colors detected)

• MUST maintain text contrast ratio of at least 4.5:1 for accessibility

Semantic Tokens

Token HEX RGB Usage

surface-base

#F2F6F9 rgb(242,246,249) Page background

surface-raised

#071A34 rgb(7,26,52) Cards, modals, raised surfaces

text-primary

#9DA1A9 rgb(157,161,169) Headings, body text

text-secondary

#B1BCC7 rgb(177,188,199) Secondary, muted text

text-tertiary

#737883 rgb(115,120,131) Additional text

border-default

#131E2B rgb(19,30,43) Subtle borders, dividers

success

#75B88A rgb(117,184,138) Success states, confirmations

accent

#517BDF rgb(81,123,223) Primary actions, links, focus

warning

#FAE6C2 rgb(250,230,194) Warning states, cautions

destructive

#D29E79 rgb(210,158,121) Error states, delete actions

Typography

• MUST use Inter as primary font family

• SHOULD use single font family for consistency

• MUST use 53px / 700 for primary headings

• MUST use 28px / semi_bold for body text

• SHOULD reduce font weights (currently 5 detected)

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

• SHOULD use tabular-nums for numeric data

• NEVER modify letter-spacing unless explicitly requested

Text Styles

Style Font Size Weight Color Count

heading-1

Inter 53px 700 #18105B 1

body

Inter 28px semi_bold #242424 1

body-secondary

Inter 27px semi_bold #2D2D2D 1

body-secondary

Inter 26px semi_bold #517BDF 1

text-24px

Inter 24px semi_bold #EBD6F3 1

text-18px

Inter 18px 500 #E76874 1

text-18px

Inter 18px semi_bold #2D2D2D 1

text-18px

Inter 18px semi_bold #3E3D3D 1

text-16px

Inter 16px 400 #F6CFB7 1

text-15px

Inter 15px 400 #626870 1

Typography Reference

Font Families:

• Inter (used 62x)

Font Sizes: 5px, 6px, 7px, 8px, 9px, 10px, 11px, 12px, 13px, 14px, 15px, 16px, 18px, 24px, 26px, 27px, 28px, 53px

Spacing

• MUST use 4px grid for spacing

• SHOULD use spacing from scale: 1px, 2px, 3px, 4px, 5px, 11px, 12px, 13px

• SHOULD use 5px as default gap between elements

• NEVER use arbitrary spacing values (use design scale)

• SHOULD maintain consistent padding within containers

Borders

• MUST use border-radius from scale: 3px, 4px, 7px, 15px, 22px, 33px, 35px

• SHOULD use 22px+ radius for pill-shaped elements

• SHOULD limit border widths to: 1px, 2px, 3px

• SHOULD use 22px as default border-radius

• NEVER use arbitrary border-radius values (use design scale)

• SHOULD use subtle borders (1px) for element separation

Border Radius Reference

Scale: 3px, 4px, 7px, 15px, 22px, 33px, 35px

Layout

• MUST design for 1920px base viewport width

• SHOULD use consistent element widths: 10px, 227px, 7px, 30px, 17px

• SHOULD maintain text-heavy layout with clear hierarchy

• NEVER use h-screen , use h-dvh for full viewport height

• MUST respect safe-area-inset for fixed elements

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

• h-*

Detected Layout Patterns

• Main Content: width: 1920px, height: 1080px

• Main Content: width: 1920px, height: 1045px

• Header: height: 69px

Components

• MUST use 0px height for input fields

Buttons

Variant Background Text Border Height Radius

Ghost transparent #737883 none

Inputs

• Height: 0px

Interactive States

Focus

• MUST use 2px outline with accent color (#517BDF )

• MUST use 2px outline-offset

• NEVER remove focus indicators

Hover

• Buttons (primary): lighten background by 10%

• Buttons (secondary): use #071A34 background

• List items: use #071A34 background

Disabled

• MUST use opacity: 0.5

• MUST use cursor: not-allowed

Interaction

• MUST use an AlertDialog for destructive or irreversible actions

• SHOULD use structural skeletons for loading states

• MUST show errors next to where the action happens

• NEVER block paste in input or textarea elements

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

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 use ease-out on entrance animations

• NEVER exceed 200ms for interaction feedback

• SHOULD respect prefers-reduced-motion

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