Beehiiv UI Skills

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

When to Apply

Reference these guidelines when:

• Building light-mode interfaces

• Creating Beehiiv-inspired design systems

• Implementing UIs with Inter font and 4px grid

Colors

• SHOULD use light backgrounds for primary surfaces

• MUST use #221FAB as page background (surface-base )

• MUST use #221FAB for primary actions and focus states (accent )

• SHOULD reduce color palette (currently 19 colors detected)

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

Semantic Tokens

Token HEX RGB Usage

surface-base

#221FAB rgb(34,31,171) Page background

surface-raised

#070512 rgb(7,5,18) Cards, modals, raised surfaces

text-primary

#B6B8E7 rgb(182,184,231) Headings, body text

text-secondary

#B9B7BF rgb(185,183,191) Secondary, muted text

text-tertiary

#626076 rgb(98,96,118) Additional text

border-default

#252494 rgb(37,36,148) Subtle borders, dividers

accent

#221FAB rgb(34,31,171) Primary actions, links, focus

Typography

• MUST use Inter as primary font family

• SHOULD use single font family for consistency

• MUST use 51px / 700 for primary headings

• MUST use 12px / 400 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 51px 700 #EF40B0 1

heading-2

Inter 51px 700 #F7F7F8 1

heading-3

Inter 51px 700 #F5F5F6 1

text-41px

Inter 41px 400 #B8B7BE 1

text-34px

Inter 34px 700 #F4F4F5 1

text-26px

Inter 26px semi_bold #CDCCD1 1

text-23px

Inter 23px semi_bold #9B99A5 1

text-23px

Inter 23px 500 #CAC9D0 1

text-23px

Inter 23px 700 #D8D7DB 1

text-23px

Inter 23px semi_bold #D1D0D5 1

Typography Reference

Font Families:

• Inter (used 61x)

Font Sizes: 5px, 8px, 9px, 10px, 11px, 12px, 13px, 14px, 15px, 16px, 17px, 18px, 19px, 20px, 21px, 22px, 23px, 26px, 34px, 41px, 51px

Spacing

• MUST use 4px grid for spacing

• SHOULD use spacing from scale: 4px, 5px, 15px, 21px, 23px, 53px, 56px, 79px

• SHOULD use 4px 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

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

• SHOULD use 3px 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

Layout

• MUST design for 1920px base viewport width

• SHOULD use consistent element widths: 13px, 14px, 26px, 31px, 65px

• 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: 999px

• Header: height: 78px

Components

Buttons

Variant Background Text Border Height Radius

Ghost transparent #B6B8E7 none

Interactive States

Focus

• MUST use 2px outline with accent color (#221FAB )

• MUST use 2px outline-offset

• NEVER remove focus indicators

Hover

• Buttons (primary): lighten background by 10%

• Buttons (secondary): use #070512 background

• List items: use #070512 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