Back to directory
dev-tool · light · minimal · developer · modern

Hairline Light.

Light dev-tool. Bone canvas with a 1px graphite hairline grid, mono-forward labels, one signal-violet accent. The aesthetic of an API console — built for developer-facing platforms that ship a light theme.

01 · Preview

The kitchen sink.

Hairline.app
ProductPricingDocsAbout
Sign inGet started
dev-tool · light · minimal

Build with Hairline Light.

A complete design system, ready for your AI coding agent. Every primitive, token, and pattern below is generated straight from DESIGN.md — drop the file in your project and ship matching UI in minutes.

Start building →View on GitHub
Featured
Tokens that travel with your prompts.
Active users
12,840
Status
All systems operational
01 · Color

Palette

primary
#0E0F12
secondary
#5A6068
tertiary
#9097A0
neutral
#F7F7F4
surface
#FFFFFF
02 · Typography

Type scale

display
The quick brown fox
h1
A major section heading
h2
A subsection title
body
Body copy in the system's body font.
03 · Buttons

Buttons

PrimarySecondaryOutlineGhostText link →
Disabled
04 · Inputs

Form controls

Email
iris@studio.com
Password
••••••••••••
Bio
Designing for long-form publications. Based in Kyoto.
05 · Choices

Select & toggle

Plan
Starter
Free forever
Pro
$18 / month
Team
$48 / month
Toggles
Public profile
Require two-factor
Auto-accept invites
06 · Tags & badges

Labeling

NeutralAccentSolidWith dot
NEWBETAv2.0LIVE
07 · Cards

Cards

Feature
Editorial rigor

Prose-first token file — decisions live next to their reasoning.

Learn more →
Metric
24,810
▲ +12.4% vs last week
08 · Navigation

Tabs & breadcrumb

Overview
Analytics
Members
Workspace/Projects/Heritage System
09 · Spacing

Spacing scale

Fine micro-scale (1–5px) for pills, editorial scale (12–21px) for the grid.

1px
2px
5px
8px · base
10px
12px
14px
16px
18px
20px
21px
10 · Radius

Border radius scale

The system's own radius tokens — sm for chips and inputs, md for buttons, lg for cards, pill for fully-rounded CTAs.

sm
4px
md
6px
lg
8px
pill
999px
11 · Elevation

Depth & elevation

00 · Flat
Elevation 00
01 · Low
Elevation 01
02 · Medium
Elevation 02
03 · High
Elevation 03
12 · Data

Charts

Weekly revenue
$48,210
M
T
W
T
F
S
S
Active sessions
2,184
02 · The file

DESIGN.md

markdown
1---
2name: "Hairline Light"
3description: "Light dev-tool. Bone canvas with a 1px graphite hairline grid, mono-forward labels, one signal-violet accent. The aesthetic of an API console — built for developer-facing platforms that ship a light theme."
4tags: ["dev-tool", light, minimal, developer, modern]
5colors:
6 primary: "#0E0F12"
7 secondary: "#5A6068"
8 tertiary: "#9097A0"
9 neutral: "#F7F7F4"
10 surface: "#FFFFFF"
11typography:
12 display: "Geist Mono"
13 body: Geist
14 mono: "Geist Mono"
15 scale:
16 hero: "4rem / 1 / 500 / -0.035em"
17 h1: "2.375rem / 1.05 / 500 / -0.03em"
18 h2: "1.25rem / 1.3 / 500 / -0.012em"
19 body: "0.9375rem / 1.6 / 400 / -0.003em"
20radius:
21 sm: 4px
22 md: 6px
23 lg: 8px
24shadows:
25 card: "0 0 0 1px rgba(14, 15, 18, 0.08)"
26 button: "0 1px 2px rgba(14, 15, 18, 0.06)"
27borders:
28 card: "1px solid rgba(14, 15, 18, 0.08)"
29 divider: "rgba(14, 15, 18, 0.10)"
30buttons:
31 primary:
32 background: #0E0F12
33 color: #F7F7F4
34 border: 1px solid #0E0F12
35 shape: rounded
36 padding: 10px 18px
37 font: mono / 500 / 0.8125rem / -0.005em
38 shadow: 0 1px 2px rgba(14, 15, 18, 0.06)
39 secondary:
40 background: #FFFFFF
41 color: #0E0F12
42 border: 1px solid rgba(14, 15, 18, 0.14)
43 shape: rounded
44 padding: 10px 18px
45 font: mono / 500 / 0.8125rem / -0.005em
46 outline:
47 background: transparent
48 color: #0E0F12
49 border: 1px dashed rgba(14, 15, 18, 0.30)
50 shape: rounded
51 padding: 10px 18px
52 font: mono / 500 / 0.8125rem / -0.005em
53 ghost:
54 background: transparent
55 color: #7C5CFA
56 border: none
57 shape: rounded
58 padding: 10px 4px
59 font: mono / 500 / 0.8125rem / -0.005em
60 hover: underline
61charts:
62 variant: "thin-bars"
63 stroke_width: 1
64 gridlines: true
65 bar_radius: 0px
66 bar_gap: 6px
67 highlight: single
68 axis_color: "#5A6068"
69 palette: ["#7C5CFA"]
70fonts_url: "https://fonts.googleapis.com/css2?family=Geist:wght@400;500;600;700&family=Geist+Mono:wght@400;500;600&display=swap"
71dependencies: ["lucide-react"]
72---
73
74# Hairline Light
75
76## AI Build Instructions
77
78> **Read this section before writing any code.** The rules below
79> are non-negotiable. Every value used in the UI must come from this
80> file's frontmatter — never substitute, approximate, or invent new
81> colors, fonts, radii, or shadows. If a value is missing, ask the
82> user before adding one.
83
84### 1 · Your role
85
86You are building UI for a project that has adopted **Hairline Light** as its
87design system. Treat `DESIGN.md` as the single source of truth.
88Your job is to translate the user's product requirements into
89components and pages that look like they were designed by the same
90person who authored this file.
91
92### 2 · Token compliance
93
94- Pull every color, font family, radius, shadow, and spacing value
95 from the frontmatter at the top of this file.
96- Use semantic roles (e.g. `primary`, `accent`, `muted`) — never
97 hard-code hex values that bypass the system.
98- When a token can be expressed as a CSS variable, declare it once
99 in your global stylesheet and reference it everywhere downstream.
100- The Google Fonts `<link>` is provided in the Typography section.
101 Add it to `<head>` before any component renders.
102
103### 3 · Component recipes
104
105Use these recipes verbatim when building the corresponding component.
106
107#### Buttons
108
109Four variants are defined. Pick one — never blend variants or invent a fifth.
110
111- **Primary** — rounded shape, bg `#0E0F12`, text `#F7F7F4`, border `1px solid #0E0F12`, padding `10px 18px`, weight `500`, shadow `0 1px 2px rgba(14, 15, 18, 0.06)`.
112- **Secondary** — rounded shape, bg `#FFFFFF`, text `#0E0F12`, border `1px solid rgba(14, 15, 18, 0.14)`, padding `10px 18px`, weight `500`.
113- **Outline** — rounded shape, text `#0E0F12`, border `1px dashed rgba(14, 15, 18, 0.30)`, padding `10px 18px`, weight `500`.
114- **Ghost** — rounded shape, text `#7C5CFA`, padding `10px 4px`, weight `500`.
115
116Reach for **primary** as the single dominant CTA per screen.
117**Secondary** for the supporting action. **Outline** for tertiary
118actions in toolbars. **Ghost** for inline links and table actions.
119
120#### Cards
121
122- Background: `#FFFFFF`
123- Border: `1px solid rgba(14, 15, 18, 0.08)`
124- Shadow: `0 0 0 1px rgba(14, 15, 18, 0.08)`
125- Radius: `radius.lg` (`8px`)
126- Internal padding: `20px` for compact cards, `24–28px` for content cards.
127
128#### Charts
129
130- Bar/line variant: `thin-bars`
131- Bar radius: `0px`
132- Highlight strategy: `single` — emphasize a single bar/point per chart.
133- Use the declared palette in order: `#7C5CFA`.
134
135#### Typography pairings
136
137- **Display (`Geist Mono`)** — h1, h2, hero headlines, brand wordmarks.
138- **Body (`Geist`)** — paragraphs, labels, button text, form inputs.
139- **Mono (`Geist Mono`)** — code, eyebrows, metadata, numerals in tables.
140
141### 4 · Hard constraints
142
143Never do any of the following without explicit instruction from the user:
144
145- Introduce a new color, font, radius, or shadow that isn't declared above.
146- Mix this system with another (e.g. don't paste in Material or Bootstrap defaults).
147- Use generic gradient defaults (purple→blue, peach→pink) — they break the system's voice.
148- Reach for emoji icons. Use a consistent icon library and size icons in line with body type.
149- Add motion that exceeds the system's restraint — keep transitions short (≤200ms) and subtle.
150
151### 5 · Before you finish — verify
152
153Run through this checklist for every screen you produce:
154
155- [ ] Every color used appears in the Colors table above.
156- [ ] Headlines use the display font; body copy uses the body font.
157- [ ] Buttons match one of the declared variants exactly (shape, padding, weight).
158- [ ] Border-radius values come from `radius.sm` / `radius.md` / `radius.lg` / `radius.pill`.
159- [ ] Cards and dividers use the declared border + shadow tokens.
160- [ ] No values were invented; if you needed something missing, you stopped and asked.
161
162---
163
164## Overview
165Hairline Light is the light counterpart to dev-tool dark systems. The page sits on a bone canvas with a 1px graphite hairline grid; type is mono-forward (Geist Mono for display + labels, Geist Sans for body); every pixel lands on a 4px subgrid. There is exactly one chromatic accent — a signal violet — and it appears only on links, ghost buttons, and the primary chart bar.
166
167The system is built for developer-facing platforms that ship a light theme: API consoles, docs sites, infra dashboards, log viewers, anything where the aesthetic is "documentation, not marketing."
168
169## Color
170- **Graphite #0E0F12** — primary text, primary fills, hairline borders.
171- **Mid Graphite #5A6068** — secondary text, axis labels.
172- **Soft Graphite #9097A0** — tertiary text, dividers at low opacity.
173- **Bone #F7F7F4** — page canvas. Slightly warm so it doesn't feel sterile.
174- **Paper #FFFFFF** — card surface.
175- **Signal Violet #7C5CFA** — the only chromatic accent. Links, ghost button label, primary chart bar.
176
177Color is rationed. The page is mostly bone and graphite with a single stroke of violet.
178
179## Typography
180The system runs on **Geist + Geist Mono**. Display and labels are mono — that single decision is the whole tonal voice.
181
182| Role | Font | Size | Weight | Tracking |
183|------|------|------|--------|----------|
184| Hero | Geist Mono | 4rem | 500 | -0.035em |
185| H1 | Geist Mono | 2.375rem | 500 | -0.03em |
186| H2 | Geist Mono | 1.25rem | 500 | -0.012em |
187| Body | Geist | 0.9375rem | 400 | -0.003em / 1.6 |
188| Button | Geist Mono | 0.8125rem | 500 | -0.005em |
189
190Body copy uses the proportional Geist; everything structural (display, button, label, table header) uses Geist Mono. The contrast between proportional body and mono structure is the entire texture.
191
192## Geometry
193- **Radii: 4 / 6 / 8.** Precise instrument geometry. Never pill, never soft.
194- **4px subgrid.** Every spacing value is a multiple of 4.
195- **Hairlines everywhere.** 1px graphite at 8-14% opacity divides every section. The page is a wireframe.
196- **Section gap: 96px** desktop, 64px mobile.
197
198## Buttons
199- **Primary** — solid graphite, bone label, mono caps. The single dark element on the page.
200- **Secondary** — surface paper with a 14% graphite hairline. Mono label.
201- **Outline** — **dashed** hairline at 30%. Dashed = "secondary action" semantics — distinct from secondary's solid border.
202- **Ghost** — bare signal-violet label, hover underline.
203
204## Cards
205Surface paper on bone, 1px graphite hairline at 8% opacity, sharp 6px corners, **no drop shadow**. Padding 24px. Cards are wireframes filled with content — the hairline is the entire structure.
206
207## Charts & Data
208Single-color thin bars in signal violet, **gridlines on** (this is a developer tool — readability beats minimalism), 6px gap, 0 corner radius. Axis labels in mid graphite at 11px Geist Mono.
209
210## Do's and Don'ts
211- ✅ Mono for display and structure. Proportional only for body.
212- ✅ Hairline borders, never drop shadows. The system is a wireframe.
213- ✅ One chromatic accent — signal violet. Used sparingly (link, ghost, primary chart bar).
214- ✅ 4px subgrid. Every spacing value is a multiple of 4.
215- ❌ No pill buttons. No soft corners. No drop shadows.
216- ❌ No second chromatic color. The page is bone + graphite + violet.
217- ❌ No proportional display type. Mono carries the identity.
218- ❌ No icons inside body text. Use mono labels.
219
220---
221
222## Tokens
223
224> Generated from the same source the live preview renders from.
225> Treat the values below as the contract — never substitute approximations.
226
227### Colors
228
229| Role | Value |
230|-----------|-------|
231| primary | `#0E0F12` |
232| secondary | `#5A6068` |
233| tertiary | `#9097A0` |
234| neutral | `#F7F7F4` |
235| surface | `#FFFFFF` |
236
237### Typography
238
239- **Display:** Geist Mono
240- **Body:** Geist
241- **Mono:** Geist Mono
242
243| Role | size / leading / weight / tracking |
244|------|------------------------------------|
245| Hero | 4rem / 1 / 500 / -0.035em |
246| H1 | 2.375rem / 1.05 / 500 / -0.03em |
247| H2 | 1.25rem / 1.3 / 500 / -0.012em |
248| Body | 0.9375rem / 1.6 / 400 / -0.003em |
249
250### Radius
251
252- sm: `4px`
253- md: `6px`
254- lg: `8px`
255
256### Shadows
257
258- **card:** `0 0 0 1px rgba(14, 15, 18, 0.08)`
259- **button:** `0 1px 2px rgba(14, 15, 18, 0.06)`
260
261### Borders
262
263- **card:** `1px solid rgba(14, 15, 18, 0.08)`
264- **divider:** `rgba(14, 15, 18, 0.10)`
265
266### Buttons
267
268Four variants, each fully tokenized. The preview renders from these exact values.
269
270#### Primary
271
272| Property | Value |
273|----------|-------|
274| shape | `rounded` |
275| background | `#0E0F12` |
276| color | `#F7F7F4` |
277| border | `1px solid #0E0F12` |
278| padding | `10px 18px` |
279| fontFamily | `mono` |
280| fontWeight | `500` |
281| fontSize | `0.8125rem` |
282| tracking | `-0.005em` |
283| shadow | `0 1px 2px rgba(14, 15, 18, 0.06)` |
284
285#### Secondary
286
287| Property | Value |
288|----------|-------|
289| shape | `rounded` |
290| background | `#FFFFFF` |
291| color | `#0E0F12` |
292| border | `1px solid rgba(14, 15, 18, 0.14)` |
293| padding | `10px 18px` |
294| fontFamily | `mono` |
295| fontWeight | `500` |
296| fontSize | `0.8125rem` |
297| tracking | `-0.005em` |
298
299#### Outline
300
301| Property | Value |
302|----------|-------|
303| shape | `rounded` |
304| background | `transparent` |
305| color | `#0E0F12` |
306| border | `1px dashed rgba(14, 15, 18, 0.30)` |
307| padding | `10px 18px` |
308| fontFamily | `mono` |
309| fontWeight | `500` |
310| fontSize | `0.8125rem` |
311| tracking | `-0.005em` |
312
313#### Ghost
314
315| Property | Value |
316|----------|-------|
317| shape | `rounded` |
318| background | `transparent` |
319| color | `#7C5CFA` |
320| border | `none` |
321| padding | `10px 4px` |
322| fontFamily | `mono` |
323| fontWeight | `500` |
324| fontSize | `0.8125rem` |
325| tracking | `-0.005em` |
326| hoverHint | `underline` |
327
328### Charts
329
330| Property | Value |
331|----------|-------|
332| variant | `thin-bars` |
333| strokeWidth | `1` |
334| gridlines | `true` |
335| barRadius | `0px` |
336| barGap | `6px` |
337| highlight | `single` |
338| axisColor | `#5A6068` |
339| palette | `#7C5CFA` |
340
03 · How to use it

Wire it into your agent.

markdown
# CLAUDE.md
Reference @DESIGN.md for all styling decisions. Apply tokens strictly — do not introduce colors, fonts, or radii outside the system. When in doubt, prefer the values declared in DESIGN.md frontmatter.
04 · Required setup

Three snippets.

Google Fonts link

html
<link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Geist:wght@400;500;600;700&family=Geist+Mono:wght@400;500;600&display=swap" />

Install dependencies

bash
npm install lucide-react

Tailwind config

js
// tailwind.config.js
export default {
theme: {
extend: {
fontFamily: {
display: ['"Geist Mono"', 'serif'],
sans: ['"Geist"', 'sans-serif'],
mono: ['"Geist Mono"', 'monospace'],
},
colors: {
primary: '#0E0F12',
secondary: '#5A6068',
accent: '#9097A0',
neutral: '#F7F7F4',
surface: '#FFFFFF',
},
borderRadius: {
sm: '4px',
md: '6px',
lg: '8px',
},
},
},
};
05 · Keep browsing

Try another system.