# Cardboard design system

> Cardboard design system measured from cardboard.ai: Denton font, #212121 primary on #000000, 14 color hex codes, type scale, spacing and a free DESIGN.md.

Canonical page: https://sitepeel.dev/design-md/cardboard.ai/

Cardboard’s website (cardboard.ai) uses the Denton font and #212121 as its main color on a black background. Measured by Sitepeel on November 6, 2026.

## What font does Cardboard use?

Cardboard uses Denton (weight 300) and Delight (weights 400 and 500) on cardboard.ai. Page titles are 54px at weight 300 (40px on phones) and body text is 14px. Measured on November 6, 2026.

- Denton (weights 300)
- Delight (weights 400, 500)
- Geist (weights 400)

## Cardboard colors: palette and hex codes

Cardboard’s main colors are #000000 (near black) for the background, #FFFFFF (white) for text and #212121 (charcoal) as the main accent, with #D97757 (red) as another accent. Measured on November 6, 2026.

- #000000: near black
- #FFFFFF: white
- #F0F0F0: mist
- #CCCCCC: silver
- #848484: gray
- #111214: charcoal
- #191919: charcoal
- #212121: charcoal

## What is Cardboard built with?

Cardboard’s website (cardboard.ai) is built with Next.js, React, Radix UI, Tailwind CSS and Vercel. Measured on November 6, 2026.

- JavaScript framework: Next.js 16.3.7, React 18.3.1
- Hosting & CDN: Vercel
- Analytics: Meta Pixel 2.9.437, PostHog, Sentry 10.38.0, Vercel Web Analytics
- UI & CSS: Radix UI, Tailwind CSS 4.x
- Animation & 3D: Motion
- Fonts & icons: Lucide

## Questions and answers

### What font does Cardboard use?

Cardboard’s website uses Denton (weight 300) and Delight (weights 400 and 500). Page titles are 54px at weight 300 (40px on phones) and body text is 14px. Measured on November 6, 2026.

### What are the Cardboard colors and hex codes?

On cardboard.ai: #000000 (near black) for the background, #FFFFFF (white) for text and #212121 (charcoal) as the main accent, with #D97757 (red) as another accent. The color palette above lists all 14 colors with their hex codes and where each one is used.

### What is the Cardboard design system?

The design system on this page is cardboard.ai’s, as measured on November 6, 2026: Denton type, #212121 as the main color and 12px corners, written down as a DESIGN.md. It is not Cardboard’s own documentation.

### What is Cardboard built with?

Cardboard’s website (cardboard.ai) is built with Next.js, React, Radix UI, Tailwind CSS and Vercel. The full tech stack Sitepeel found: Next.js, Vercel, React, Meta Pixel, PostHog, Sentry, Vercel Web Analytics, X Pixel, Radix UI and Tailwind CSS. Measured on November 6, 2026.

### What is the Cardboard DESIGN.md?

A plain-text file with Cardboard’s measured colors, type, spacing, corners and components as tokens, plus short rules, in the DESIGN.md format Google published with Stitch. Your AI coding agent reads it and builds in this style. More about DESIGN.md.

### How do I use it with Claude Code or Cursor?

Download the file and put it in your project’s root folder, then ask your agent to follow DESIGN.md. Step-by-step guides: Claude Code, Cursor, Codex, GitHub Copilot.

### Is this Cardboard’s official design system?

No. Sitepeel measured it from cardboard.ai’s public page on November 6, 2026. It is an independent analysis, not made or approved by Cardboard.

### Can I use Cardboard’s style in my own product?

Use it to learn, prototype and compare. For a real product, make the style your own, and never copy Cardboard’s logo, name, pictures or text.

### How accurate are the values?

Each value was measured on the rendered page after it fully loaded, on desktop and mobile: colors where they appear, type with tracking, spacing, corners, shadows and hover states. Sites change, so check the date at the top.

## Files

- [DESIGN.md](https://sitepeel.dev/design-md/cardboard.ai/DESIGN.md): the plain file to put in your project.
- [All brand DESIGN.md files](https://sitepeel.dev/design-md/examples/index.md)

Independent analysis by Sitepeel (sitepeel.dev), not affiliated with Cardboard.

## The DESIGN.md file

```markdown
---
version: alpha
name: Cardboard
description: "Dark monochrome interface measured from cardboard.ai: Denton type with Delight, tonal surfaces and 12px corners."
colors:
  background: "#000000"
  surface: "#000000"
  on-surface: "#FFFFFF"
  on-background: "#FFFFFF"
  on-surface-variant: "#F0F0F0"
  on-surface-muted: "#CCCCCC"
  on-surface-subtle: "#848484"
  surface-container-low: "#111214"
  surface-container: "#191919"
  surface-container-high: "#212121"
  overlay: "#2A2A2A26"
  overlay-strong: "#FFFFFF12"
  outline: "#6E9BFF29"
  primary: "#212121"
  on-primary: "#FFFFFF"
  secondary: "#D97757"
typography:
  headline-display:
    fontFamily: Denton
    fontSize: 54px
    fontWeight: 300
    lineHeight: 1.02
  headline-lg:
    fontFamily: Denton
    fontSize: 40px
    fontWeight: 300
    lineHeight: 1.1
  headline-md:
    fontFamily: Delight
    fontSize: 28px
    fontWeight: 400
    lineHeight: 1
  headline-sm:
    fontFamily: Denton
    fontSize: 24px
    fontWeight: 300
    lineHeight: 0.94
  title-lg:
    fontFamily: Delight
    fontSize: 20px
    fontWeight: 500
    lineHeight: 1.4
  body-md:
    fontFamily: Delight
    fontSize: 14px
    fontWeight: 400
    lineHeight: 1.5
  body-lg:
    fontFamily: Delight
    fontSize: 15px
    fontWeight: 400
    lineHeight: 1.5
    letterSpacing: 0.033em
  body-sm:
    fontFamily: Delight
    fontSize: 13px
    fontWeight: 400
    lineHeight: 1.4
  caption:
    fontFamily: Geist
    fontSize: 11px
    fontWeight: 400
    lineHeight: 1.5
  label-lg:
    fontFamily: Delight
    fontSize: 16px
    fontWeight: 500
    lineHeight: 1.5
  label-md:
    fontFamily: Delight
    fontSize: 15px
    fontWeight: 500
    lineHeight: 1.5
  label-sm:
    fontFamily: Delight
    fontSize: 14px
    fontWeight: 500
    lineHeight: 1.2
  headline-display-mobile:
    fontFamily: Denton
    fontSize: 40px
    fontWeight: 300
    lineHeight: 1.02
  headline-lg-mobile:
    fontFamily: Denton
    fontSize: 32px
    fontWeight: 300
    lineHeight: 1.1
  title-lg-mobile:
    fontFamily: Geist
    fontSize: 11px
    fontWeight: 400
    lineHeight: 1.5
  headline-md-mobile:
    fontFamily: Delight
    fontSize: 14px
    fontWeight: 400
    lineHeight: 1.5
rounded:
  sm: 5px
  md: 7.5px
  lg: 12px
  xl: 20px
spacing:
  xs: 2px
  sm: 8px
  md: 16px
  lg: 20px
  xl: 48px
  gutter: 16px
  section: 96px
  margin: 80px
  container: 1440px
components:
  button-primary:
    backgroundColor: "{colors.primary}"
    typography: "{typography.body-md}"
    rounded: "{rounded.lg}"
    padding: 8px 14px
    height: 33px
  button-secondary:
    backgroundColor: "{colors.surface-container-high}"
    textColor: "{colors.on-surface}"
    typography: "{typography.label-sm}"
    rounded: "{rounded.lg}"
    padding: 8.75px 14px
    height: 34px
  button-tertiary:
    backgroundColor: "{colors.on-surface}"
    textColor: "{colors.background}"
    typography: "{typography.label-sm}"
    rounded: "{rounded.lg}"
    padding: 8.75px 14px
    height: 34px
  button-ghost:
    textColor: "{colors.on-surface}"
    typography: "{typography.label-sm}"
    rounded: 6px
    padding: 0px
  input-field:
    textColor: "{colors.on-surface}"
    typography: "{typography.label-lg}"
    rounded: 0px
    padding: 0px
  card:
    backgroundColor: "{colors.surface-container-low}"
    textColor: "#D9D9D9"
    typography: "{typography.body-md}"
    rounded: "{rounded.xl}"
    padding: 28px
  link:
    textColor: "#FFFFFF99"
---

# Cardboard Design System

## Overview

Cardboard describes itself as: “An agentic AI video editor in your browser and on your Mac. Describe your edit and Cardboard cuts, captions, reframes, and composes it.” The interface is dark, built on **Near Black (#000000)** with **White (#FFFFFF)** text and almost no color: actions are carried by contrast, not hue.

Type is set in **Denton** and **Delight**. Headlines run large; body text is 14px. The surface language is flat. Corners are mostly 12px.

Measured from [cardboard.ai](https://www.cardboard.ai/) on November 6, 2026 at 1440×900 and 390×844 from 453 rendered elements. Values are computed styles from the live page, not the original source files.

## Colors

The palette has 14 roles, plus gradient stops #D1E6FF, #0A1B2E, #0A2C4B, #0A3C67.

- **Near Black (#000000):** Page background, seen 2 times. Token `background`.
- **White (#FFFFFF):** Primary text and headings, seen 46 times. Token `on-surface`, CSS `--color-white`.
- **Mist (#F0F0F0):** Secondary text, seen 3 times. Token `on-surface-variant`.
- **Silver (#CCCCCC):** Muted text and metadata, seen 2 times. Token `on-surface-muted`.
- **Gray (#848484):** Subtle text and placeholders, seen 6 times. Token `on-surface-subtle`.
- **Charcoal (#111214):** Raised areas one step from the page, seen 3 times. Token `surface-container-low`.
- **Charcoal (#191919):** Cards and panels, seen 63 times. Token `surface-container`.
- **Charcoal (#212121):** Hover and pressed fills, seen 7 times. Token `surface-container-high`.
- **Graphite 15% (#2A2A2A26):** Translucent fill for cards and controls, seen 6 times. Token `overlay`.
- **White 7% (#FFFFFF12):** Stronger translucent fill, seen 1 time. Token `overlay-strong`.
- **Light Blue 16% (#6E9BFF29):** Borders and dividers, seen 1 time. Token `outline`.
- **Charcoal (#212121):** Primary buttons and calls to action, seen 8 times. Token `primary`.
- **White (#FFFFFF):** Text and icons on primary. Token `on-primary`.
- **Red (#D97757):** Accent, seen 1 time. Token `secondary`.

## Typography

**Denton**, **Delight** and **Geist** share the interface. Fallback stack: `Denton, Raveo Variable Variable, serif`. Other loaded fonts: Inter, Raveo Variable Variable.

- **headline-display:** Denton 54px at weight 300, line height 1.02 (40px on mobile). Page title (h1).
- **headline-lg:** Denton 40px at weight 300, line height 1.1 (32px on mobile). Section headings (h2).
- **headline-md:** Delight 28px at weight 400, line height 1 (14px on mobile). Sub-section headings.
- **headline-sm:** Denton 24px at weight 300, line height 0.94. Card and feature titles.
- **title-lg:** Delight 20px at weight 500, line height 1.4 (11px on mobile). Small titles.
- **body-md:** Delight 14px at weight 400, line height 1.5. Body text.
- **body-lg:** Delight 15px at weight 400, line height 1.5, tracking 0.033em. Lead paragraphs.
- **body-sm:** Delight 13px at weight 400, line height 1.4. Secondary and small text.
- **caption:** Geist 11px at weight 400, line height 1.5. Captions and fine print.
- **label-lg:** Delight 16px at weight 500, line height 1.5. Large buttons and tabs.
- **label-md:** Delight 15px at weight 500, line height 1.5. Buttons, navigation and labels.
- **label-sm:** Delight 14px at weight 500, line height 1.2. Small labels and badges.

## Layout

Spacing is mostly on a 4px grid (72% of measured values), with some off-grid steps. Match the measured scale rather than rounding everything.

- **Scale:** xs 2px, sm 8px, md 16px, lg 20px, xl 48px.
- **Sections:** 96px vertical padding between major sections.
- **Gaps:** 16px is the most common gap in flex and grid layouts.
- **Container:** content is capped at 1440px.
- **Page margin:** 80px on each side of full-width sections.
- **Breakpoints:** 840px, 1400px, 1440px, 1600px.

## Elevation & Depth

The design is flat: no shadows were measured. Hierarchy comes from tonal surface steps (#111214 → #191919 → #212121) and #6E9BFF29 borders.

## Shapes

Most elements use 12px corners. Measured radii, most used first:

- **lg (12px):** 304 elements.
- **sm (5px):** 36 elements.
- **md (7.5px):** 36 elements.
- **xl (20px):** 16 elements.

## Components

Measured from the rendered page. Token values reference the tokens above.

- **button-primary (“Launch Video”):** #212121 fill, #00000000 text, 14px/400, 12px radius, padding 8px 14px.
- **button-secondary (“Login”):** #212121 fill, #FFFFFF text, 14px/500, 12px radius, padding 8.75px 14px.
- **button-tertiary (“Get started”):** #FFFFFF fill, #000000 text, 14px/500, 12px radius, padding 8.75px 14px.
- **button-ghost (“Auto”):** transparent fill, #FFFFFF text, 14px/500, 6px radius, padding 0px.
- **input-field (“Describe your video, or drop foo”):** transparent fill, #FFFFFF text, 16px/500, padding 0px.
- **card:** #111214 fill, #D9D9D9 text, 14px/400, 20px radius, padding 28px.
- **link:** transparent fill, #FFFFFF99 text, padding 0px.

## Do's and Don'ts

- Do use #000000 for the page and lift surfaces in small steps: #111214, #191919, #212121.
- Do keep text in 4 levels: #FFFFFF, #F0F0F0, #CCCCCC, #848484.
- Do let contrast carry emphasis; primary actions use #212121 on #000000.
- Do reuse the measured spacing steps (8px, 16px, 20px).
- Do use 12px corners on most elements; larger surfaces also use 5px, 7.5px and 20px.
- Don't add drop shadows for depth; use tonal surfaces.
- Don't introduce new font families beyond Denton, Delight and Geist.
- Don't add saturated accent colors; the measured palette is almost entirely neutral.
- Don't make interface transitions slower than 0.4s.

## Motion

Interface transitions are quick: 0.4s, 0.2s, 0.15s, 0.3s.

- **Easing:** `cubic-bezier(0.16, 1, 0.3, 1)`, `cubic-bezier(0, 0, 0.2, 1)`, `cubic-bezier(0.4, 0, 0.2, 1)`.
- **Reduced motion:** the page responds to `prefers-reduced-motion`.

Generated by [Sitepeel](https://sitepeel.dev/design-md/cardboard.ai/), the free DESIGN.md generator (engine 2026.10.29+b828a475ee10).

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