Clerk UI Skills
Opinionated constraints for building Clerk-style interfaces with AI agents.
When to Apply
Reference these guidelines when:
- Building light-mode interfaces
- Creating Clerk-inspired design systems
- Implementing UIs with Inter font and 4px grid
Colors
- SHOULD use light backgrounds for primary surfaces
- MUST use
#FEFEFE as page background (surface-base)
- MUST use
#C4A9F3 for primary actions and focus states (accent)
- SHOULD reduce color palette (currently 12 colors detected)
- MUST maintain text contrast ratio of at least 4.5:1 for accessibility
Semantic Tokens
| Token |
HEX |
RGB |
Usage |
surface-base |
#FEFEFE |
rgb(254,254,254) |
Page background |
surface-raised |
#090909 |
rgb(9,9,9) |
Cards, modals, raised surfaces |
text-primary |
#5C5C5C |
rgb(92,92,92) |
Headings, body text |
text-secondary |
#98979D |
rgb(152,151,157) |
Secondary, muted text |
text-tertiary |
#2F2F2F |
rgb(47,47,47) |
Additional text |
border-default |
#E4E4E1 |
rgb(228,228,225) |
Subtle borders, dividers |
accent |
#C4A9F3 |
rgb(196,169,243) |
Primary actions, links, focus |
Typography
- MUST use
Inter as primary font family
- SHOULD use single font family for consistency
- MUST use
66px / 700 for primary headings
- MUST use
26px / 700 for body text
- SHOULD reduce font weights (currently 4 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 |
66px |
700 |
#262628 |
1 |
body |
Inter |
26px |
700 |
#292929 |
1 |
text-19px |
Inter |
19px |
500 |
#4D4D4D |
1 |
text-18px |
Inter |
18px |
500 |
#303030 |
1 |
text-18px |
Inter |
18px |
400 |
#525252 |
1 |
text-17px |
Inter |
17px |
500 |
#E9E9E9 |
1 |
text-17px |
Inter |
17px |
400 |
#838285 |
1 |
text-16px |
Inter |
16px |
500 |
#2F2F2F |
1 |
text-16px |
Inter |
16px |
300 |
#F5F5F5 |
1 |
text-15px |
Inter |
15px |
400 |
#BDBDBD |
1 |
Typography Reference
Font Families:
Font Sizes: 9px, 11px, 12px, 14px, 15px, 16px, 17px, 18px, 19px, 26px, 66px
Spacing
- MUST use 4px grid for spacing
- SHOULD use spacing from scale: 1px, 2px, 4px, 5px, 16px, 37px, 49px, 51px
- 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: 4px, 6px, 7px
- MUST use 1px border width consistently
- SHOULD use 6px 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: 4px, 6px, 7px
Layout
- MUST design for 1920px base viewport width
- SHOULD use consistent element widths: 8px, 52px, 44px, 363px, 71px
- 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: 584px
Components
- MUST use
0px height for input fields
Buttons
| Variant |
Background |
Text |
Border |
Height |
Radius |
| Ghost |
transparent |
#BDBDBD |
none |
- |
- |
Inputs
Interactive States
Focus
- MUST use
2px outline with accent color (#C4A9F3)
- MUST use
2px outline-offset
- NEVER remove focus indicators
Hover
- Buttons (primary): lighten background by 10%
- Buttons (secondary): use
#090909 background
- List items: use
#090909 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
1---2name: clerk-ui-skills3description: Clerk's UI design system. Use when building interfaces inspired by Clerk's aesthetic - light mode, Inter font, 4px grid.4license: MIT5---6
7# Clerk UI Skills
8
9Opinionated constraints for building Clerk-style interfaces with AI agents.
10
11## When to Apply
12
13Reference these guidelines when:
14- Building light-mode interfaces
15- Creating Clerk-inspired design systems
16- Implementing UIs with Inter font and 4px grid
17
18## Colors
19
20- SHOULD use light backgrounds for primary surfaces
21- MUST use `#FEFEFE` as page background (`surface-base`)
22- MUST use `#C4A9F3` for primary actions and focus states (`accent`)
23- SHOULD reduce color palette (currently 12 colors detected)
24- MUST maintain text contrast ratio of at least 4.5:1 for accessibility
25
26### Semantic Tokens
27
28| Token | HEX | RGB | Usage |
29|-------|-----|-----|-------|
30| `surface-base` | #FEFEFE | rgb(254,254,254) | Page background |
31| `surface-raised` | #090909 | rgb(9,9,9) | Cards, modals, raised surfaces |
32| `text-primary` | #5C5C5C | rgb(92,92,92) | Headings, body text |
33| `text-secondary` | #98979D | rgb(152,151,157) | Secondary, muted text |
34| `text-tertiary` | #2F2F2F | rgb(47,47,47) | Additional text |
35| `border-default` | #E4E4E1 | rgb(228,228,225) | Subtle borders, dividers |
36| `accent` | #C4A9F3 | rgb(196,169,243) | Primary actions, links, focus |
37
38## Typography
39
40- MUST use `Inter` as primary font family
41- SHOULD use single font family for consistency
42- MUST use `66px` / `700` for primary headings
43- MUST use `26px` / `700` for body text
44- SHOULD reduce font weights (currently 4 detected)
45- MUST use `text-balance` for headings and `text-pretty` for body text
46- SHOULD use `tabular-nums` for numeric data
47- NEVER modify letter-spacing unless explicitly requested
48
49### Text Styles
50
51| Style | Font | Size | Weight | Color | Count |
52|-------|------|------|--------|-------|-------|
53| `heading-1` | Inter | 66px | 700 | #262628 | 1 |
54| `body` | Inter | 26px | 700 | #292929 | 1 |
55| `text-19px` | Inter | 19px | 500 | #4D4D4D | 1 |
56| `text-18px` | Inter | 18px | 500 | #303030 | 1 |
57| `text-18px` | Inter | 18px | 400 | #525252 | 1 |
58| `text-17px` | Inter | 17px | 500 | #E9E9E9 | 1 |
59| `text-17px` | Inter | 17px | 400 | #838285 | 1 |
60| `text-16px` | Inter | 16px | 500 | #2F2F2F | 1 |
61| `text-16px` | Inter | 16px | 300 | #F5F5F5 | 1 |
62| `text-15px` | Inter | 15px | 400 | #BDBDBD | 1 |
63
64### Typography Reference
65
66**Font Families:**
67- `Inter` (used 28x)
68
69**Font Sizes:** 9px, 11px, 12px, 14px, 15px, 16px, 17px, 18px, 19px, 26px, 66px
70
71## Spacing
72
73- MUST use 4px grid for spacing
74- SHOULD use spacing from scale: 1px, 2px, 4px, 5px, 16px, 37px, 49px, 51px
75- SHOULD use 5px as default gap between elements
76- NEVER use arbitrary spacing values (use design scale)
77- SHOULD maintain consistent padding within containers
78
79## Borders
80
81- MUST use border-radius from scale: 4px, 6px, 7px
82- MUST use 1px border width consistently
83- SHOULD use 6px as default border-radius
84- NEVER use arbitrary border-radius values (use design scale)
85- SHOULD use subtle borders (1px) for element separation
86
87### Border Radius Reference
88
89**Scale:** 4px, 6px, 7px
90
91## Layout
92
93- MUST design for 1920px base viewport width
94- SHOULD use consistent element widths: 8px, 52px, 44px, 363px, 71px
95- SHOULD maintain text-heavy layout with clear hierarchy
96- NEVER use `h-screen`, use `h-dvh` for full viewport height
97- MUST respect `safe-area-inset` for fixed elements
98- SHOULD use `size-*` for square elements instead of `w-*` + `h-*`
99
100### Detected Layout Patterns
101
102- **Main Content**: width: 1920px, height: 584px
103
104## Components
105
106- MUST use `0px` height for input fields
107
108### Buttons
109
110| Variant | Background | Text | Border | Height | Radius |
111|---------|------------|------|--------|--------|--------|
112| Ghost | transparent | #BDBDBD | none | - | - |
113
114### Inputs
115
116- Height: `0px`
117
118## Interactive States
119
120### Focus
121
122- MUST use `2px` outline with accent color (`#C4A9F3`)
123- MUST use `2px` outline-offset
124- NEVER remove focus indicators
125
126### Hover
127
128- Buttons (primary): lighten background by 10%
129- Buttons (secondary): use `#090909` background
130- List items: use `#090909` background
131
132### Disabled
133
134- MUST use `opacity: 0.5`
135- MUST use `cursor: not-allowed`
136
137## Interaction
138
139- MUST use an `AlertDialog` for destructive or irreversible actions
140- SHOULD use structural skeletons for loading states
141- MUST show errors next to where the action happens
142- NEVER block paste in `input` or `textarea` elements
143- MUST add an `aria-label` to icon-only buttons
144
145## Animation
146
147- NEVER add animation unless it is explicitly requested
148- MUST animate only compositor props (`transform`, `opacity`)
149- NEVER animate layout properties (`width`, `height`, `top`, `left`, `margin`, `padding`)
150- SHOULD use `ease-out` on entrance animations
151- NEVER exceed `200ms` for interaction feedback
152- SHOULD respect `prefers-reduced-motion`
153
154## Performance
155
156- NEVER animate large `blur()` or `backdrop-filter` surfaces
157- NEVER apply `will-change` outside an active animation
158- NEVER use `useEffect` for anything that can be expressed as render logic