Carbon
A dark-first minimal theme: near-black surfaces, crisp white type, tight radii, and zero noise for focused tools and editors.
Build something people love.
A live preview of this theme — every color, font, radius, and shadow you see is rendered straight from its tokens.
Color system
Click any swatch to copy. Contrast graded against WCAG.
Typography
Body sample. Geist carries running text — readable paragraphs, comfortable measure, and a rhythm that holds up across long pages of content and UI.
Radius, shadow & fonts
Components
Real UI rendered with this theme's tokens.
A surface for grouping content, with the theme's border, radius, and shadow.
Principles, guidelines & component specs
Do's & don'ts, spacing, motion, iconography, accessibility, and exact component specs — all in the design.md too.
Do
- •Keep chrome monochrome so content colour stands out.
- •Make the light mode intentional, not an afterthought.
Don't
- •Don't soften with big radii or warm tints.
- •Don't add accent hues to the UI.
- •Fast, quiet motion for a focused, tool-like feel.
Hover to feel this theme's base transition.
Lucide · 1.5px stroke · 1rem. Outline icons with a consistent stroke width; size icons to match adjacent text and align them optically.
- Never use color as the only signal — pair it with text, an icon, or a shape.
- Every interactive element must be keyboard reachable and show a visible focus ring.
- Honor prefers-reduced-motion: reduce by disabling non-essential animation.
- Keep a logical heading order and give every form control a label.
Button
| Background | var(--primary) |
| Text | var(--primary-foreground) |
| Radius | 0.375rem |
| Padding | 0 1rem |
| Height | 2.5rem |
| Weight | 600 |
Badge
| Background | var(--accent) / var(--primary) |
| Text | var(--accent-foreground) / var(--primary-foreground) |
| Radius | 0.25rem |
| Padding | 0.15rem 0.55rem |
| Font size | 0.72rem |
| Weight | 600 |
Use for status, counts, and short labels. Keep to one or two words.
Alert
| Radius | 0.563rem |
| Padding | 1rem 1.25rem |
| Border | 1px solid var(--border) |
Always pair the color with an icon and a text label — never rely on color alone.
Form field
| Background | var(--background) |
| Border | 1px solid var(--input) |
| Radius | 0.375rem |
| Height | 2.5rem |
| Padding | 0.5rem 0.75rem |
Label sits above the field; helper or error text sits below.
Card
| Background | var(--card) |
| Text | var(--card-foreground) |
| Border | 1px solid var(--border) |
| Radius | 0.5rem |
| Padding | 1.25rem |
| Shadow | 0 8px 22px -6px rgba(0,0,0,0.50) |
The design brief
Carbon is a dark-first minimal design system for focused tools, editors, and developer apps. Near-black surfaces with crisp white type and tight radii keep attention on the work.
Principles
- Dark-first, but with an intentional, legible light mode.
- Tight radii and thin borders for an engineered, quiet feel.
- Monochrome by default — colour is the user's content, not the chrome.
When to use
Use Carbon for code editors, focus tools, and pro apps where the UI should disappear. Avoid it for warm consumer brands.
Signature details
- Near-black
#09090bsurfaces, white type, 0.375rem radius. - Geist + JetBrains Mono.
Use this with your AI
Download or copy the design.md and paste it into Claude, Cursor, or v0 — it tells the agent exactly which colors, fonts, radii, and shadows to use, so your site comes out looking like this.
Export tokens
Drop straight into your codebase.
:root {
--radius: 0.375rem;
--background: #ffffff;
--foreground: #09090b;
--card: #ffffff;
--card-foreground: #09090b;
--popover: #ffffff;
--popover-foreground: #09090b;
--primary: #18181b;
--primary-foreground: #fafafa;
--secondary: #f4f4f5;
--secondary-foreground: #18181b;
--muted: #f4f4f5;
--muted-foreground: #52525b;
--accent: #ececee;
--accent-foreground: #18181b;
--destructive: #dc2626;
--destructive-foreground: #ffffff;
--border: #e4e4e7;
--input: #e4e4e7;
--ring: #18181b;
--shadow-sm: 0 1px 2px rgba(0,0,0,0.30);
--shadow-md: 0 8px 22px -6px rgba(0,0,0,0.50);
--shadow-lg: 0 24px 52px -12px rgba(0,0,0,0.65);
--font-sans: 'Geist', ui-sans-serif, system-ui, sans-serif;
--font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, monospace;
--ease-standard: cubic-bezier(0.4,0,0.2,1);
--ease-emphasized: cubic-bezier(0.16,1,0.3,1);
--duration-base: 210ms;
}
.dark {
--background: #09090b;
--foreground: #fafafa;
--card: #0f0f11;
--card-foreground: #fafafa;
--popover: #0f0f11;
--popover-foreground: #fafafa;
--primary: #fafafa;
--primary-foreground: #09090b;
--secondary: #161618;
--secondary-foreground: #fafafa;
--muted: #161618;
--muted-foreground: #a1a1aa;
--accent: #1d1d20;
--accent-foreground: #fafafa;
--destructive: #f87171;
--destructive-foreground: #450a0a;
--border: #222225;
--input: #222225;
--ring: #fafafa;
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