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dark · minimal · engineering · saas · modern

Halogen Editor.

Dark-mode-native canvas where content emerges like starlight. Geometric variable sans, the signature 510 weight, semi-transparent white borders, and a single indigo-violet accent.

01 · Preview

The kitchen sink.

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dark · minimal · engineering

Build with Halogen Editor.

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
#F7F8F8
secondary
#D0D6E0
tertiary
#7170FF
neutral
#08090A
surface
#0F1011
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
2px
md
6px
lg
12px
pill
9999px
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: "Halogen Editor"
3description: "Dark-mode-native canvas where content emerges like starlight. Geometric variable sans, the signature 510 weight, semi-transparent white borders, and a single indigo-violet accent."
4tags: [dark, minimal, engineering, saas, modern]
5colors:
6 primary: "#f7f8f8"
7 secondary: "#d0d6e0"
8 tertiary: "#7170ff"
9 neutral: "#08090a"
10 surface: "#0f1011"
11typography:
12 display: Inter
13 body: Inter
14 mono: "JetBrains Mono"
15 scale:
16 hero: "4.5rem / 1 / 510 / -1.584px"
17 h1: "3rem / 1 / 510 / -1.056px"
18 h2: "2rem / 1.13 / 400 / -0.704px"
19 body: "1rem / 1.5 / 400 / 0"
20radius:
21 sm: 2px
22 md: 6px
23 lg: 12px
24 pill: 9999px
25shadows:
26 card: "rgba(255,255,255,0.08) 0 0 0 1px, rgba(0,0,0,0.4) 0 2px 4px"
27 button: "rgba(94,106,210,0.35) 0 0 0 1px, rgba(0,0,0,0.4) 0 4px 12px"
28buttons:
29 primary:
30 background: #5E6AD2
31 color: #FFFFFF
32 border: none
33 shape: rounded
34 padding: 8px 14px
35 font: 510 / 0.8125rem
36 shadow: rgba(94,106,210,0.32) 0 0 0 1px, rgba(94,106,210,0.18) 0 4px 12px -4px
37 secondary:
38 background: rgba(255,255,255,0.06)
39 color: #F7F8F8
40 border: 1px solid rgba(255,255,255,0.10)
41 shape: rounded
42 padding: 8px 14px
43 font: 510 / 0.8125rem
44 outline:
45 background: transparent
46 color: #F7F8F8
47 border: 1px solid rgba(255,255,255,0.14)
48 shape: rounded
49 padding: 8px 14px
50 font: 510 / 0.8125rem
51 ghost:
52 background: transparent
53 color: rgba(247,248,248,0.6)
54 border: none
55 shape: rounded
56 padding: 8px 10px
57 font: 510 / 0.8125rem
58charts:
59 variant: bars
60 stroke_width: 1.5
61 fill_opacity: 0.25
62 gridlines: true
63 bar_radius: 2px
64 bar_gap: 8px
65 highlight: all
66 dot_marker: true
67fonts_url: "https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600&family=JetBrains+Mono:wght@400&display=swap"
68dependencies: ["lucide-react"]
69---
70
71# Halogen Editor
72
73## AI Build Instructions
74
75> **Read this section before writing any code.** The rules below
76> are non-negotiable. Every value used in the UI must come from this
77> file's frontmatter — never substitute, approximate, or invent new
78> colors, fonts, radii, or shadows. If a value is missing, ask the
79> user before adding one.
80
81### 1 · Your role
82
83You are building UI for a project that has adopted **Halogen Editor** as its
84design system. Treat `DESIGN.md` as the single source of truth.
85Your job is to translate the user's product requirements into
86components and pages that look like they were designed by the same
87person who authored this file.
88
89### 2 · Token compliance
90
91- Pull every color, font family, radius, shadow, and spacing value
92 from the frontmatter at the top of this file.
93- Use semantic roles (e.g. `primary`, `accent`, `muted`) — never
94 hard-code hex values that bypass the system.
95- When a token can be expressed as a CSS variable, declare it once
96 in your global stylesheet and reference it everywhere downstream.
97- The Google Fonts `<link>` is provided in the Typography section.
98 Add it to `<head>` before any component renders.
99
100### 3 · Component recipes
101
102Use these recipes verbatim when building the corresponding component.
103
104#### Buttons
105
106Four variants are defined. Pick one — never blend variants or invent a fifth.
107
108- **Primary** — rounded shape, bg `#5E6AD2`, text `#FFFFFF`, padding `8px 14px`, weight `510`, shadow `rgba(94,106,210,0.32) 0 0 0 1px, rgba(94,106,210,0.18) 0 4px 12px -4px`.
109- **Secondary** — rounded shape, bg `rgba(255,255,255,0.06)`, text `#F7F8F8`, border `1px solid rgba(255,255,255,0.10)`, padding `8px 14px`, weight `510`.
110- **Outline** — rounded shape, text `#F7F8F8`, border `1px solid rgba(255,255,255,0.14)`, padding `8px 14px`, weight `510`.
111- **Ghost** — rounded shape, text `rgba(247,248,248,0.6)`, padding `8px 10px`, weight `510`.
112
113Reach for **primary** as the single dominant CTA per screen.
114**Secondary** for the supporting action. **Outline** for tertiary
115actions in toolbars. **Ghost** for inline links and table actions.
116
117#### Cards
118
119- Background: `#0f1011`
120- Shadow: `rgba(255,255,255,0.08) 0 0 0 1px, rgba(0,0,0,0.4) 0 2px 4px`
121- Radius: `radius.lg` (`12px`)
122- Internal padding: `20px` for compact cards, `24–28px` for content cards.
123
124#### Charts
125
126- Bar/line variant: `bars`
127- Bar radius: `2px`
128- Highlight strategy: `all` — emphasize a single bar/point per chart.
129
130#### Typography pairings
131
132- **Display (`Inter`)** — h1, h2, hero headlines, brand wordmarks.
133- **Body (`Inter`)** — paragraphs, labels, button text, form inputs.
134- **Mono (`JetBrains Mono`)** — code, eyebrows, metadata, numerals in tables.
135
136### 4 · Hard constraints
137
138Never do any of the following without explicit instruction from the user:
139
140- Introduce a new color, font, radius, or shadow that isn't declared above.
141- Mix this system with another (e.g. don't paste in Material or Bootstrap defaults).
142- Use generic gradient defaults (purple→blue, peach→pink) — they break the system's voice.
143- Reach for emoji icons. Use a consistent icon library and size icons in line with body type.
144- Add motion that exceeds the system's restraint — keep transitions short (≤200ms) and subtle.
145
146### 5 · Before you finish — verify
147
148Run through this checklist for every screen you produce:
149
150- [ ] Every color used appears in the Colors table above.
151- [ ] Headlines use the display font; body copy uses the body font.
152- [ ] Buttons match one of the declared variants exactly (shape, padding, weight).
153- [ ] Border-radius values come from `radius.sm` / `radius.md` / `radius.lg` / `radius.pill`.
154- [ ] Cards and dividers use the declared border + shadow tokens.
155- [ ] No values were invented; if you needed something missing, you stopped and asked.
156
157---
158
159## 1. Atmosphere
160
161Halogen Editor is dark-mode native. The canvas (`#08090a`) is near-black with the faintest blue-cool undertone, and content emerges from it like starlight — a calibrated luminance hierarchy from barely-visible borders (`rgba(255,255,255,0.05)`) up to soft, luminous text (`#f7f8f8`). This is not a dark theme bolted onto a light design; darkness is the medium, and information density is managed through gradations of white opacity rather than color shifts.
162
163The typography is built entirely on a geometric variable sans with OpenType alternates enabled globally for a cleaner, more engineered character. Weight **510** — sitting between regular (400) and medium (500) — is the signature: a subtle emphasis that doesn't shout. Display sizes (72/64/48px) use aggressive negative tracking (-1.584px to -1.056px) for compressed, authoritative headlines.
164
165The palette is almost entirely achromatic — dark surfaces, white-opacity text — punctuated by a single brand accent: indigo-violet (`#5e6ad2` for backgrounds, `#7170ff` for interactive). Borders are wisp-thin semi-transparent whites that suggest structure without visual noise, like wireframes drawn in moonlight.
166
167**Signature moves**
168- `#08090a` marketing canvas, `#0f1011` panels, `#191a1b` elevated surfaces
169- Variable sans with weight 510 as the workhorse
170- Aggressive display tracking: -1.584px at 72px, -1.056px at 48px
171- Single chromatic accent: `#5e6ad2` / `#7170ff` / `#828fff` — used only for CTAs and brand
172- Borders as semi-transparent white: `rgba(255,255,255,0.05–0.08)`
173- Button surfaces at near-zero opacity: `rgba(255,255,255,0.02–0.05)`
174- Multi-layer shadows with inset variants for depth on dark
175
176## 2. Palette
177
178### Surfaces
179- Marketing `#08090a` — deepest canvas
180- Panel `#0f1011` — sidebars, panels
181- Level 3 `#191a1b` — elevated surfaces, cards
182- Secondary `#28282c` — hover states
183
184### Text
185- Primary `#f7f8f8` — barely-warm near-white (never `#ffffff` — too harsh)
186- Secondary `#d0d6e0` — silver-gray body
187- Tertiary `#8a8f98` — placeholders, metadata
188- Quaternary `#62666d` — timestamps, disabled
189
190### Brand
191- Indigo `#5e6ad2` — primary CTA background
192- Violet `#7170ff` — interactive accent
193- Hover `#828fff` — lighter saturated variant
194
195### Status
196- Green `#27a644` — in-progress
197- Emerald `#10b981` — completion pills
198
199### Borders
200- Subtle `rgba(255,255,255,0.05)` — default
201- Standard `rgba(255,255,255,0.08)` — cards, inputs
202- Solid Primary `#23252a` — prominent separations
203
204## 3. Typography
205
206| Role | Size | Weight | Leading | Tracking |
207|------|------|--------|---------|----------|
208| Display XL | 72px | 510 | 1.00 | -1.584px |
209| Display | 48px | 510 | 1.00 | -1.056px |
210| Heading 1 | 32px | 400 | 1.13 | -0.704px |
211| Heading 3 | 20px | 590 | 1.33 | -0.24px |
212| Body L | 18px | 400 | 1.60 | -0.165px |
213| Body | 16px | 400 | 1.50 | normal |
214| Body Medium | 16px | 510 | 1.50 | normal |
215| Caption | 13px | 400 | 1.50 | -0.13px |
216| Mono | 14px | 400 | 1.50 | normal |
217
218**510 is the signature weight.** Between regular (400) and medium (500), it produces emphasis without heaviness. Three-tier system: 400 (read), 510 (emphasize / UI), 590 (announce).
219
220## 4. Buttons
221
222### Brand Indigo (Primary)
223```css
224background: #5e6ad2;
225color: #ffffff;
226padding: 8px 16px;
227border-radius: 6px;
228```
229Hover shifts to `#828fff`.
230
231### Ghost
232- Background `rgba(255,255,255,0.02)`
233- Text `#e2e4e7`
234- Border `1px solid rgb(36, 40, 44)`, radius 6px
235- Focus: `rgba(0,0,0,0.1) 0 4px 12px`
236
237### Subtle / Toolbar
238- Background `rgba(255,255,255,0.04)` or `rgba(255,255,255,0.05)`
239- 12px text at weight 510, radius 2–6px
240
241### Pill / Filter
242- Transparent background, `#d0d6e0` text
243- `1px solid rgb(35,37,42)`, radius 9999px
244
245## 5. Cards
246
247- Background: `rgba(255,255,255,0.02)` to `rgba(255,255,255,0.05)` (always translucent — never solid)
248- Border: `1px solid rgba(255,255,255,0.08)`
249- Radius: 8px standard, 12px featured, 22px large panels
250- Hover: subtle background opacity bump
251
252## 6. Spacing
253
254- Base: 8px
255- Scale: `1, 4, 7, 8, 11, 12, 16, 19, 20, 22, 24, 28, 32, 35`
256- 7px and 11px exist for optical alignment
257- Section vertical: 80px+
258
259## 7. Radius scale
260
261`2 / 4 / 6 / 8 / 12 / 22 / 9999 / 50%` — circle for icon buttons, pill for chips, 6px for buttons.
262
263## 8. Depth & elevation
264
265| Level | Treatment | Use |
266|-------|-----------|-----|
267| 0 | Flat `#08090a` | Page background |
268| 1 | `rgba(0,0,0,0.03) 0 1.2px 0` | Toolbar buttons |
269| 2 | `rgba(255,255,255,0.05)` bg + `rgba(255,255,255,0.08)` border | Cards |
270| 3 | `rgba(0,0,0,0.4) 0 2px 4px` | Floating, dropdowns |
271| 4 | Multi-layer stack | Popovers, command palette |
272
273**Elevation through luminance, not shadow.** On dark, traditional drop shadows disappear. Halogen Editor stacks elevation by stepping the white opacity of each surface (`0.02 → 0.04 → 0.05`), producing depth without color.
274
275## 9. Do's & don'ts
276
277✅ **Do**
278- Build on `#08090a` / `#0f1011` / `#191a1b` surfaces
279- Use weight 510 as your default emphasis
280- Apply aggressive negative tracking at display sizes
281- Reserve indigo (`#5e6ad2`) for CTAs and brand only
282- Use `#f7f8f8` for primary text — never pure white
283
284❌ **Don't**
285- Use pure white text — `#f7f8f8` prevents eye strain
286- Apply solid colored backgrounds to buttons — translucency is the system
287- Decorate with the brand indigo — it is for interaction only
288- Use positive tracking on display text
289- Add warm tones — the palette is cool gray with one violet accent
290
291---
292
293## Tokens
294
295> Generated from the same source the live preview renders from.
296> Treat the values below as the contract — never substitute approximations.
297
298### Colors
299
300| Role | Value |
301|-----------|-------|
302| primary | `#f7f8f8` |
303| secondary | `#d0d6e0` |
304| tertiary | `#7170ff` |
305| neutral | `#08090a` |
306| surface | `#0f1011` |
307
308### Typography
309
310- **Display:** Inter
311- **Body:** Inter
312- **Mono:** JetBrains Mono
313
314| Role | size / leading / weight / tracking |
315|------|------------------------------------|
316| Hero | 4.5rem / 1 / 510 / -1.584px |
317| H1 | 3rem / 1 / 510 / -1.056px |
318| H2 | 2rem / 1.13 / 400 / -0.704px |
319| Body | 1rem / 1.5 / 400 / 0 |
320
321### Radius
322
323- sm: `2px`
324- md: `6px`
325- lg: `12px`
326- pill: `9999px`
327
328### Shadows
329
330- **card:** `rgba(255,255,255,0.08) 0 0 0 1px, rgba(0,0,0,0.4) 0 2px 4px`
331- **button:** `rgba(94,106,210,0.35) 0 0 0 1px, rgba(0,0,0,0.4) 0 4px 12px`
332
333### Buttons
334
335Four variants, each fully tokenized. The preview renders from these exact values.
336
337#### Primary
338
339| Property | Value |
340|----------|-------|
341| shape | `rounded` |
342| background | `#5E6AD2` |
343| color | `#FFFFFF` |
344| border | `none` |
345| padding | `8px 14px` |
346| fontWeight | `510` |
347| fontSize | `0.8125rem` |
348| shadow | `rgba(94,106,210,0.32) 0 0 0 1px, rgba(94,106,210,0.18) 0 4px 12px -4px` |
349
350#### Secondary
351
352| Property | Value |
353|----------|-------|
354| shape | `rounded` |
355| background | `rgba(255,255,255,0.06)` |
356| color | `#F7F8F8` |
357| border | `1px solid rgba(255,255,255,0.10)` |
358| padding | `8px 14px` |
359| fontWeight | `510` |
360| fontSize | `0.8125rem` |
361
362#### Outline
363
364| Property | Value |
365|----------|-------|
366| shape | `rounded` |
367| background | `transparent` |
368| color | `#F7F8F8` |
369| border | `1px solid rgba(255,255,255,0.14)` |
370| padding | `8px 14px` |
371| fontWeight | `510` |
372| fontSize | `0.8125rem` |
373
374#### Ghost
375
376| Property | Value |
377|----------|-------|
378| shape | `rounded` |
379| background | `transparent` |
380| color | `rgba(247,248,248,0.6)` |
381| border | `none` |
382| padding | `8px 10px` |
383| fontWeight | `510` |
384| fontSize | `0.8125rem` |
385
386### Charts
387
388| Property | Value |
389|----------|-------|
390| variant | `bars` |
391| strokeWidth | `1.5` |
392| fillOpacity | `0.25` |
393| gridlines | `true` |
394| barRadius | `2px` |
395| barGap | `8px` |
396| highlight | `all` |
397| dotMarker | `true` |
398
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=Inter:wght@300;400;500;600&family=JetBrains+Mono:wght@400&display=swap" />

Install dependencies

bash
npm install lucide-react

Tailwind config

js
// tailwind.config.js
export default {
theme: {
extend: {
fontFamily: {
display: ['"Inter"', 'serif'],
sans: ['"Inter"', 'sans-serif'],
mono: ['"JetBrains Mono"', 'monospace'],
},
colors: {
primary: '#f7f8f8',
secondary: '#d0d6e0',
accent: '#7170ff',
neutral: '#08090a',
surface: '#0f1011',
},
borderRadius: {
sm: '2px',
md: '6px',
lg: '12px',
},
},
},
};
05 · Keep browsing

Try another system.