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-skills
3description: Segment's UI design system. Use when building interfaces inspired by Segment's aesthetic - light mode, Inter font, 4px grid.
4license: MIT
5metadata:
6 author: design-skills
7 version: "1.0.0"
8 source: https://segment.com
9---
10
11# Segment UI Skills
12
13Opinionated constraints for building Segment-style interfaces with AI agents.
14
15## When to Apply
16
17Reference these guidelines when:
18- Building light-mode interfaces
19- Creating Segment-inspired design systems
20- Implementing UIs with Inter font and 4px grid
21
22## Colors
23
24- SHOULD use light backgrounds for primary surfaces
25- MUST use `#0748D8` as page background (`surface-base`)
26- MUST use `#94C2F0` for primary actions and focus states (`accent`)
27- SHOULD reduce color palette (currently 14 colors detected)
28- MUST maintain text contrast ratio of at least 4.5:1 for accessibility
29
30### Semantic Tokens
31
32| Token | HEX | RGB | Usage |
33|-------|-----|-----|-------|
34| `surface-base` | #0748D8 | rgb(7,72,216) | Page background |
35| `surface-raised` | #000000 | rgb(0,0,0) | Cards, modals, raised surfaces |
36| `surface-overlay` | #0F1423 | rgb(15,20,35) | Overlays, tooltips, dropdowns |
37| `text-primary` | #2F3239 | rgb(47,50,57) | Headings, body text |
38| `text-2` | #424856 | rgb(66,72,86) | Additional text |
39| `text-secondary` | #94C2F0 | rgb(148,194,240) | Secondary, muted text |
40| `border-default` | #1148C1 | rgb(17,72,193) | Subtle borders, dividers |
41| `accent` | #94C2F0 | rgb(148,194,240) | Primary actions, links, focus |
42
43## Typography
44
45- MUST use `Inter` as primary font family
46- SHOULD use single font family for consistency
47- MUST use `50px` / `700` for primary headings
48- MUST use `31px` / `500` for body text
49- SHOULD reduce font weights (currently 5 detected)
50- MUST use `text-balance` for headings and `text-pretty` for body text
51- SHOULD use `tabular-nums` for numeric data
52- NEVER modify letter-spacing unless explicitly requested
53
54### Text Styles
55
56| Style | Font | Size | Weight | Color | Count |
57|-------|------|------|--------|-------|-------|
58| `heading-1` | Inter | 50px | 700 | #E1E4E6 | 1 |
59| `heading-2` | Inter | 46px | semi_bold | #2F3239 | 1 |
60| `heading-3` | Inter | 46px | 700 | #222730 | 1 |
61| `body` | Inter | 31px | 500 | #2D2C41 | 1 |
62| `text-21px` | Inter | 21px | 400 | #B1B7C2 | 1 |
63| `text-18px` | Inter | 18px | 400 | #54575E | 1 |
64| `text-16px` | Inter | 16px | 300 | #87A1D0 | 1 |
65| `text-15px` | Inter | 15px | 400 | #5F6165 | 1 |
66| `text-15px` | Inter | 15px | 400 | #484A50 | 1 |
67| `text-15px` | Inter | 15px | 400 | #52545B | 1 |
68
69### Typography Reference
70
71**Font Families:**
72- `Inter` (used 20x)
73
74**Font Sizes:** 5px, 10px, 13px, 14px, 15px, 16px, 18px, 21px, 31px, 46px, 50px
75
76## Spacing
77
78- MUST use 4px grid for spacing
79- SHOULD use spacing from scale: 1px, 2px, 3px, 4px, 5px, 16px, 18px, 78px
80- SHOULD use 2px as default gap between elements
81- NEVER use arbitrary spacing values (use design scale)
82- SHOULD maintain consistent padding within containers
83
84## Borders
85
86- MUST use border-radius from scale: 6px, 7px
87- MUST use 1px border width consistently
88- SHOULD use 6px as default border-radius
89- NEVER use arbitrary border-radius values (use design scale)
90- SHOULD use subtle borders (1px) for element separation
91
92### Border Radius Reference
93
94**Scale:** 6px, 7px
95
96## Layout
97
98- MUST design for 1920px base viewport width
99- SHOULD use consistent element widths: 8px, 248px, 11px, 476px, 96px
100- SHOULD maintain text-heavy layout with clear hierarchy
101- NEVER use `h-screen`, use `h-dvh` for full viewport height
102- MUST respect `safe-area-inset` for fixed elements
103- SHOULD use `size-*` for square elements instead of `w-*` + `h-*`
104
105### Detected Layout Patterns
106
107- **Main Content**: width: 1920px, height: 545px
108- **Main Content**: width: 1920px, height: 543px
109- **Header**: height: 44px
110- **Header**: height: 55px
111- **Header**: height: 53px
112
113## Components
114
115### Buttons
116
117| Variant | Background | Text | Border | Height | Radius |
118|---------|------------|------|--------|--------|--------|
119| Ghost | transparent | #94C2F0 | none | - | - |
120
121## Interactive States
122
123### Focus
124
125- MUST use `2px` outline with accent color (`#94C2F0`)
126- MUST use `2px` outline-offset
127- NEVER remove focus indicators
128
129### Hover
130
131- Buttons (primary): lighten background by 10%
132- Buttons (secondary): use `#000000` background
133- List items: use `#000000` background
134
135### Disabled
136
137- MUST use `opacity: 0.5`
138- MUST use `cursor: not-allowed`
139
140## Interaction
141
142- MUST use an `AlertDialog` for destructive or irreversible actions
143- SHOULD use structural skeletons for loading states
144- MUST show errors next to where the action happens
145- NEVER block paste in `input` or `textarea` elements
146- MUST add an `aria-label` to icon-only buttons
147
148## Animation
149
150- NEVER add animation unless it is explicitly requested
151- MUST animate only compositor props (`transform`, `opacity`)
152- NEVER animate layout properties (`width`, `height`, `top`, `left`, `margin`, `padding`)
153- SHOULD use `ease-out` on entrance animations
154- NEVER exceed `200ms` for interaction feedback
155- SHOULD respect `prefers-reduced-motion`
156
157## Performance
158
159- NEVER animate large `blur()` or `backdrop-filter` surfaces
160- NEVER apply `will-change` outside an active animation
161- NEVER use `useEffect` for anything that can be expressed as render logic