metadata.json
{
"version": "1.0.0",
"organization": "Slack",
"source": "https://slack.com",
"extracted": "2026-01-25",
"categories": [
"ui-design",
"light-mode"
],
"tokens": {
"colors": 8,
"typography": 53,
"spacing": 0,
"borders": 6
}
}SKILL.md
---
name: slack-ui-skills
description: Slack's UI design system. Use when building interfaces inspired by Slack's aesthetic - light mode, Inter font, 4px grid.
license: MIT
metadata:
author: design-skills
version: "1.0.0"
source: https://slack.com
---
# 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