Segment UI Skills
Opinionated constraints for building Segment-style interfaces with AI agents.
When to Apply
Reference these guidelines when:
- Building light-mode interfaces
- Creating Segment-inspired design systems
- Implementing UIs with Inter font and 4px grid
Colors
- SHOULD use light backgrounds for primary surfaces
- MUST use
#0748D8 as page background (surface-base)
- MUST use
#94C2F0 for primary actions and focus states (accent)
- SHOULD reduce color palette (currently 14 colors detected)
- MUST maintain text contrast ratio of at least 4.5:1 for accessibility
Semantic Tokens
| Token |
HEX |
RGB |
Usage |
surface-base |
#0748D8 |
rgb(7,72,216) |
Page background |
surface-raised |
#000000 |
rgb(0,0,0) |
Cards, modals, raised surfaces |
surface-overlay |
#0F1423 |
rgb(15,20,35) |
Overlays, tooltips, dropdowns |
text-primary |
#2F3239 |
rgb(47,50,57) |
Headings, body text |
text-2 |
#424856 |
rgb(66,72,86) |
Additional text |
text-secondary |
#94C2F0 |
rgb(148,194,240) |
Secondary, muted text |
border-default |
#1148C1 |
rgb(17,72,193) |
Subtle borders, dividers |
accent |
#94C2F0 |
rgb(148,194,240) |
Primary actions, links, focus |
Typography
- MUST use
Inter as primary font family
- SHOULD use single font family for consistency
- MUST use
50px / 700 for primary headings
- MUST use
31px / 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 |
50px |
700 |
#E1E4E6 |
1 |
heading-2 |
Inter |
46px |
semi_bold |
#2F3239 |
1 |
heading-3 |
Inter |
46px |
700 |
#222730 |
1 |
body |
Inter |
31px |
500 |
#2D2C41 |
1 |
text-21px |
Inter |
21px |
400 |
#B1B7C2 |
1 |
text-18px |
Inter |
18px |
400 |
#54575E |
1 |
text-16px |
Inter |
16px |
300 |
#87A1D0 |
1 |
text-15px |
Inter |
15px |
400 |
#5F6165 |
1 |
text-15px |
Inter |
15px |
400 |
#484A50 |
1 |
text-15px |
Inter |
15px |
400 |
#52545B |
1 |
Typography Reference
Font Families:
Font Sizes: 5px, 10px, 13px, 14px, 15px, 16px, 18px, 21px, 31px, 46px, 50px
Spacing
- MUST use 4px grid for spacing
- SHOULD use spacing from scale: 1px, 2px, 3px, 4px, 5px, 16px, 18px, 78px
- 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: 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: 6px, 7px
Layout
- MUST design for 1920px base viewport width
- SHOULD use consistent element widths: 8px, 248px, 11px, 476px, 96px
- 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: 545px
- Main Content: width: 1920px, height: 543px
- Header: height: 44px
- Header: height: 55px
- Header: height: 53px
Components
Buttons
| Variant |
Background |
Text |
Border |
Height |
Radius |
| Ghost |
transparent |
#94C2F0 |
none |
- |
- |
Interactive States
Focus
- MUST use
2px outline with accent color (#94C2F0)
- MUST use
2px outline-offset
- NEVER remove focus indicators
Hover
- Buttons (primary): lighten background by 10%
- Buttons (secondary): use
#000000 background
- List items: use
#000000 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: segment-ui-skills3description: Segment's UI design system. Use when building interfaces inspired by Segment's aesthetic - light mode, Inter font, 4px grid.4license: MIT5---6
7# Segment UI Skills
8
9Opinionated constraints for building Segment-style interfaces with AI agents.
10
11## When to Apply
12
13Reference these guidelines when:
14- Building light-mode interfaces
15- Creating Segment-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 `#0748D8` as page background (`surface-base`)
22- MUST use `#94C2F0` for primary actions and focus states (`accent`)
23- SHOULD reduce color palette (currently 14 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` | #0748D8 | rgb(7,72,216) | Page background |
31| `surface-raised` | #000000 | rgb(0,0,0) | Cards, modals, raised surfaces |
32| `surface-overlay` | #0F1423 | rgb(15,20,35) | Overlays, tooltips, dropdowns |
33| `text-primary` | #2F3239 | rgb(47,50,57) | Headings, body text |
34| `text-2` | #424856 | rgb(66,72,86) | Additional text |
35| `text-secondary` | #94C2F0 | rgb(148,194,240) | Secondary, muted text |
36| `border-default` | #1148C1 | rgb(17,72,193) | Subtle borders, dividers |
37| `accent` | #94C2F0 | rgb(148,194,240) | Primary actions, links, focus |
38
39## Typography
40
41- MUST use `Inter` as primary font family
42- SHOULD use single font family for consistency
43- MUST use `50px` / `700` for primary headings
44- MUST use `31px` / `500` for body text
45- SHOULD reduce font weights (currently 5 detected)
46- MUST use `text-balance` for headings and `text-pretty` for body text
47- SHOULD use `tabular-nums` for numeric data
48- NEVER modify letter-spacing unless explicitly requested
49
50### Text Styles
51
52| Style | Font | Size | Weight | Color | Count |
53|-------|------|------|--------|-------|-------|
54| `heading-1` | Inter | 50px | 700 | #E1E4E6 | 1 |
55| `heading-2` | Inter | 46px | semi_bold | #2F3239 | 1 |
56| `heading-3` | Inter | 46px | 700 | #222730 | 1 |
57| `body` | Inter | 31px | 500 | #2D2C41 | 1 |
58| `text-21px` | Inter | 21px | 400 | #B1B7C2 | 1 |
59| `text-18px` | Inter | 18px | 400 | #54575E | 1 |
60| `text-16px` | Inter | 16px | 300 | #87A1D0 | 1 |
61| `text-15px` | Inter | 15px | 400 | #5F6165 | 1 |
62| `text-15px` | Inter | 15px | 400 | #484A50 | 1 |
63| `text-15px` | Inter | 15px | 400 | #52545B | 1 |
64
65### Typography Reference
66
67**Font Families:**
68- `Inter` (used 20x)
69
70**Font Sizes:** 5px, 10px, 13px, 14px, 15px, 16px, 18px, 21px, 31px, 46px, 50px
71
72## Spacing
73
74- MUST use 4px grid for spacing
75- SHOULD use spacing from scale: 1px, 2px, 3px, 4px, 5px, 16px, 18px, 78px
76- SHOULD use 2px as default gap between elements
77- NEVER use arbitrary spacing values (use design scale)
78- SHOULD maintain consistent padding within containers
79
80## Borders
81
82- MUST use border-radius from scale: 6px, 7px
83- MUST use 1px border width consistently
84- SHOULD use 6px as default border-radius
85- NEVER use arbitrary border-radius values (use design scale)
86- SHOULD use subtle borders (1px) for element separation
87
88### Border Radius Reference
89
90**Scale:** 6px, 7px
91
92## Layout
93
94- MUST design for 1920px base viewport width
95- SHOULD use consistent element widths: 8px, 248px, 11px, 476px, 96px
96- SHOULD maintain text-heavy layout with clear hierarchy
97- NEVER use `h-screen`, use `h-dvh` for full viewport height
98- MUST respect `safe-area-inset` for fixed elements
99- SHOULD use `size-*` for square elements instead of `w-*` + `h-*`
100
101### Detected Layout Patterns
102
103- **Main Content**: width: 1920px, height: 545px
104- **Main Content**: width: 1920px, height: 543px
105- **Header**: height: 44px
106- **Header**: height: 55px
107- **Header**: height: 53px
108
109## Components
110
111### Buttons
112
113| Variant | Background | Text | Border | Height | Radius |
114|---------|------------|------|--------|--------|--------|
115| Ghost | transparent | #94C2F0 | none | - | - |
116
117## Interactive States
118
119### Focus
120
121- MUST use `2px` outline with accent color (`#94C2F0`)
122- MUST use `2px` outline-offset
123- NEVER remove focus indicators
124
125### Hover
126
127- Buttons (primary): lighten background by 10%
128- Buttons (secondary): use `#000000` background
129- List items: use `#000000` background
130
131### Disabled
132
133- MUST use `opacity: 0.5`
134- MUST use `cursor: not-allowed`
135
136## Interaction
137
138- MUST use an `AlertDialog` for destructive or irreversible actions
139- SHOULD use structural skeletons for loading states
140- MUST show errors next to where the action happens
141- NEVER block paste in `input` or `textarea` elements
142- MUST add an `aria-label` to icon-only buttons
143
144## Animation
145
146- NEVER add animation unless it is explicitly requested
147- MUST animate only compositor props (`transform`, `opacity`)
148- NEVER animate layout properties (`width`, `height`, `top`, `left`, `margin`, `padding`)
149- SHOULD use `ease-out` on entrance animations
150- NEVER exceed `200ms` for interaction feedback
151- SHOULD respect `prefers-reduced-motion`
152
153## Performance
154
155- NEVER animate large `blur()` or `backdrop-filter` surfaces
156- NEVER apply `will-change` outside an active animation
157- NEVER use `useEffect` for anything that can be expressed as render logic