Slack UI Skills

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

When to Apply

Reference these guidelines when:

Building light-mode interfaces
Creating Slack-inspired design systems
Implementing UIs with Inter font and 4px grid

Colors

SHOULD use light backgrounds for primary surfaces
MUST use #FFFFFF as page background (surface-base)
MUST use #481652 for primary actions and focus states (accent)
SHOULD reduce color palette (currently 31 colors detected)
MUST maintain text contrast ratio of at least 4.5:1 for accessibility

Semantic Tokens

Token	HEX	RGB	Usage
`surface-base`	#FFFFFF	rgb(255,255,255)	Page background
`surface-raised`	#D9EDE7	rgb(217,237,231)	Cards, modals, raised surfaces
`surface-overlay`	#3F1652	rgb(63,22,82)	Overlays, tooltips, dropdowns
`text-primary`	#0F0F0F	rgb(15,15,15)	Headings, body text
`text-secondary`	#6B9389	rgb(107,147,137)	Secondary, muted text
`text-tertiary`	#656A66	rgb(101,106,102)	Additional text
`border-default`	#BDA6BE	rgb(189,166,190)	Subtle borders, dividers
`accent`	#481652	rgb(72,22,82)	Primary actions, links, focus

Typography

MUST use Inter as primary font family
SHOULD use single font family for consistency
MUST use 61px / 700 for primary headings
MUST use 22px / 500 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	61px	700	#141414	1
`text-50px`	Inter	50px	700	#0F0F0F	1
`text-49px`	Inter	49px	700	#0F0F0F	1
`body`	Inter	22px	500	#949494	1
`body-secondary`	Inter	22px	semi_bold	#262626	1
`body-secondary`	Inter	21px	semi_bold	#4A4F4B	1
`body-secondary`	Inter	20px	500	#747474	1
`body-secondary`	Inter	20px	400	#4C4C4C	1
`text-18px`	Inter	18px	400	#7A7A7A	1
`text-17px`	Inter	17px	400	#6B9389	1

Typography Reference

Font Families:

Inter (used 53x)

Font Sizes: 6px, 7px, 8px, 9px, 10px, 11px, 12px, 13px, 14px, 15px, 16px, 17px, 18px, 20px, 21px, 22px, 49px, 50px, 61px

Spacing

MUST use 4px grid for spacing
SHOULD use spacing from scale: 1px, 2px, 4px, 5px, 6px, 7px, 9px, 10px
SHOULD use 2px 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: 1px, 3px, 4px, 8px, 9px, 16px
SHOULD limit border widths to: 1px, 2px
SHOULD use 4px 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: 1px, 3px, 4px, 8px, 9px, 16px

Layout

MUST design for 1920px base viewport width
SHOULD use consistent element widths: 15px, 67px, 13px, 16px, 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: 619px

Components

MUST use 0px height for input fields

Buttons

Variant	Background	Text	Border	Height	Radius
Ghost	transparent	#5B887D	none	-	-

Inputs

Height: 0px

Interactive States

Focus

MUST use 2px outline with accent color (#481652)
MUST use 2px outline-offset
NEVER remove focus indicators

Hover

Buttons (primary): lighten background by 10%
Buttons (secondary): use #D9EDE7 background
List items: use #D9EDE7 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

slack-ui-skills