MozaikaDesign system

Cal.com — Design System

light · modern · medium · custom · confidence 90% · deep decode

Cal.com built its own display face and leads with it: Cal Sans at 64px/600 in charcoal #242424 on warm grey #F4F4F4, Inter at 16px underneath, 12px-radius buttons. Booking-page embeds appear as live, functional heroes — scheduling infrastructure that proves itself by letting you book the demo inside the landing page.

Open in Mozaika →

This is a static, crawlable rendering for search & AI engines. The interactive version — filters, live decode console, copy & export — is at https://mozaika.design/ds/cal-com.

Tokens

Cal.com's decoded design system: background #F4F4F4, text #374151, accent #0000EE, link #0000EE, primary #374151; type scale h1 64px / h2 48px / body 14px; 4px spacing base; 8px base radius. The single interactive/action color is #0000EE — used only on interactive or must-notice elements (buttons, links, key highlights), never on large fills.

Color roles

RoleValue
bg#F4F4F4
surface#E8E9EA
border#D7D9DB
text#374151
text_muted#7E858E
primary#374151
accent#0000EE
link#0000EE
secondary#9CA3AF
button_bgrgba(0, 0, 0, 0)
button_text#0000EE

Using these colors

Typography

Spacing

Radii

Shadows (elevation)

Native design tokens

TokenValue
--sj-tw-ring-colorrgba(59,130,246,.5)
--sj-tw-ring-offset-color#fff
--sj-tw-ring-offset-width0px

Button states (measured)

Motion choreography (measured)

Scroll reveal: 15 elements rest at opacity 0, translateY(-35px), animate in over 700ms.

Responsive (measured)

Per-section tokens (11)

Export: DESIGN.md

# Cal.com — Design System

> light, modern, medium, custom — deep decode (measured live)

Cal.com built its own display face and leads with it: Cal Sans at 64px/600 in charcoal #242424 on warm grey #F4F4F4, Inter at 16px underneath, 12px-radius buttons. Booking-page embeds appear as live, functional heroes — scheduling infrastructure that proves itself by letting you book the demo inside the landing page.

## Colors

| Role | Value |
|------|-------|
| bg | `#F4F4F4` |
| surface | `#E8E9EA` |
| border | `#D7D9DB` |
| text | `#374151` |
| text_muted | `#7E858E` |
| primary | `#374151` |
| accent | `#0000EE` |
| link | `#0000EE` |
| secondary | `#9CA3AF` |
| button_bg | `rgba(0, 0, 0, 0)` |
| button_text | `#0000EE` |

**Using these colors**

- **Action color** `#0000EE` — the single interactive color; it appears only on things you click or must notice (buttons, key highlights), never on large fills or backgrounds.
- `accent`, `link` are all `#0000EE` — one role, not several (your action color).
- **accent** `#0000EE` — THE accent / action color — interactive & must-notice only (buttons, links, focus, one key highlight); never large fills or backgrounds. Scarcity is what makes it read as designed.
- **primary** `#374151` — ≈ the text color — a foreground/text color, not an action color (action = #0000EE).
- **secondary** `#9CA3AF` — optional secondary accent — LOW decode confidence; use rarely (a status color or a single decorative moment) or omit it entirely. Prefer one accent unless the reference clearly shows two.
- **Page coverage** (full-page screenshot pixels): `#F4F4F4` 94.6% · `#C1C1C1` 5.4%

## Typography

- Heading: **Cal Sans** _(free fallback: Newsreader)_
- Body: **Inter**
- Mono: **Roboto Mono** _(measured)_

| Role | Size / weight · line-height · tracking |
|------|------------------------------------------|
| hero | 64px / 600 · lh 70px |
| h2 | 48px / 600 · lh 53px |
| h3 | 24px / 600 · lh 31px |
| body | 16px / 300 · lh 24px |
| small | 14px / 300 · lh 20px |

- Weight ladder: 300 · 400 · 500 · 600 — use these exact measured weights, not the 400/600 defaults.

> **Fonts —** Cal Sans may be proprietary — safe free fallback: Newsreader (Google Fonts). Inter — free, on Google.

## Spacing
- base unit: 4px (inferred from the measured scale)
- measured scale: 2px, 4px, 6px, 8px, 10px, 12px, 16px, 20px, 24px, 28px — snap all gaps/padding to these

## Radius
- base: 8px
- button: 12px
- card: 100px
- pill: 9999px
- sharp: 2px

## Buttons

| Button | Fill / text | Border | Radius | Padding | Font | Shadow |
|--------|-------------|--------|--------|---------|------|--------|
| primary | `rgba(0, 0, 0, 0)` / `#0000EE` | none | 12px | 8px 12px 8px 12px | 400 12px | rgba(255, 255, 255, 0.15) 0px 2px 0px 0px inset |
| secondary | `rgba(0, 0, 0, 0)` / `#0000EE` | none | 12px | 8px 12px 8px 12px | 400 12px | rgb(255, 255, 255) 0px 2px 0px 0px inset |

**States (measured, not guessed)**

- primary focus: outline `1px auto rgb(16, 16, 16)`

## Shadows (elevation)
- subtle: `rgba(0, 0, 0, 0) 0px 1px 3px 0px, rgba(0, 0, 0, 0) 0px 0px 2px 0px`
- card: `rgba(19, 19, 22, 0.7) 0px 1px 5px -4px, rgba(34, 42, 53, 0.08) 0px 0px 0px 1px, rgba(34, 42, 53, 0.05) 0px 4px 8px 0px`

## Their own tokens (verbatim from :root)

| Token | Value |
|-------|-------|
| `--sj-tw-ring-color` | `rgba(59,130,246,.5)` |
| `--sj-tw-ring-offset-color` | `#fff` |
| `--sj-tw-ring-offset-width` | `0px` |

Prefer these names when extending their system — it's the brand's actual vocabulary.

## Motion choreography (measured)
- scroll reveal: 15 elements rest at opacity 0, translateY(-35px), animate in over 700ms (4 revealed during the drive).

Rebuild the timeline, not just the durations — order, delays and staggers above are the choreography.

## Components (measured)
- link: #111111 · no underline — hover rgba(17, 17, 17, 0.5)

## Responsive (measured)
- breakpoints: 640px · 768px · 809px · 1024px · 1199px
- mobile (390px): hero 40px · body 12px · nav: inline

## How to apply
Paste the Tailwind `@theme` (or CSS variables) as your base, then build each
section to its spec — verify every color, radius, and font against these tokens.
Hover/focus states, shadows and motion timings above are measured from the live page — match them exactly, don't re-guess them.

---

> **Decoded with Mozaika** — measured live, not guessed. Full decoded design system + one-command install: mozaika.design/ds/cal-com

Export: Tailwind v4 (@theme)

@theme {
  /* action color #0000EE — the one interactive color; buttons/links/emphasis only, never large fills. */
  --color-bg: #F4F4F4;
  --color-surface: #E8E9EA;
  --color-border: #D7D9DB;
  --color-text: #374151;
  --color-text-muted: #7E858E;
  --color-primary: #374151;  /* ≈ the text color — a foreground/text color, not an action color (action = #0000EE). */
  --color-accent: #0000EE;  /* THE accent / action color — interactive & must-notice only (buttons, links, focus, one key highlight); never large fills or backgrounds. Scarcity is what makes it read as designed. */
  --color-link: #0000EE;  /* inline text links — shares the action color. */
  --color-secondary: #9CA3AF;  /* optional secondary accent — LOW decode confidence; use rarely (a status color or a single decorative moment) or omit it entirely. Prefer one accent unless the reference clearly shows two. */
  --color-button-bg: rgba(0, 0, 0, 0);
  --color-button-text: #0000EE;
  /* fonts: Cal Sans may be proprietary — safe free fallback: Newsreader (Google Fonts). Inter — free, on Google. */
  --font-heading: "Cal Sans", "Newsreader", system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-body: "Inter", system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-mono: "Roboto Mono", ui-monospace, monospace;
  /* measured weights: 300, 400, 500, 600 — use these, not 400/600 */
  --text-hero: 64px; --font-weight-hero: 600; --leading-hero: 70px;
  --text-h2: 48px; --font-weight-h2: 600; --leading-h2: 53px;
  --text-h3: 24px; --font-weight-h3: 600; --leading-h3: 31px;
  --text-body: 16px; --font-weight-body: 300; --leading-body: 24px;
  --text-small: 14px; --font-weight-small: 300; --leading-small: 20px;
  --radius-base: 8px;
  --radius-button: 12px;
  --radius-card: 100px;
  --radius-pill: 9999px;
  --radius-sharp: 2px;
  --shadow-card: rgba(19, 19, 22, 0.7) 0px 1px 5px -4px, rgba(34, 42, 53, 0.08) 0px 0px 0px 1px, rgba(34, 42, 53, 0.05) 0px 4px 8px 0px;
  --shadow-subtle: rgba(0, 0, 0, 0) 0px 1px 3px 0px, rgba(0, 0, 0, 0) 0px 0px 2px 0px;
  --outline-focus: 1px auto rgb(16, 16, 16);  /* measured focus ring */
  --spacing: 4px;  /* measured base — drives the p-*/gap-* scale. steps seen on the page: 2, 4, 6, 8, 10, 12, 16, 20, 24, 28px */
}

Export: CSS variables

:root {
  /* action color #0000EE — the one interactive color; buttons/links/emphasis only, never large fills. */
  --bg: #F4F4F4;
  --surface: #E8E9EA;
  --border: #D7D9DB;
  --text: #374151;
  --text-muted: #7E858E;
  --primary: #374151;  /* ≈ the text color — a foreground/text color, not an action color (action = #0000EE). */
  --accent: #0000EE;  /* THE accent / action color — interactive & must-notice only (buttons, links, focus, one key highlight); never large fills or backgrounds. Scarcity is what makes it read as designed. */
  --link: #0000EE;  /* inline text links — shares the action color. */
  --secondary: #9CA3AF;  /* optional secondary accent — LOW decode confidence; use rarely (a status color or a single decorative moment) or omit it entirely. Prefer one accent unless the reference clearly shows two. */
  --button-bg: rgba(0, 0, 0, 0);
  --button-text: #0000EE;
  --font-heading: "Cal Sans", "Newsreader", system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-body: "Inter", system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-mono: "Roboto Mono", ui-monospace, monospace;
  --text-hero: 64px; --weight-hero: 600; --leading-hero: 70px;
  --text-h2: 48px; --weight-h2: 600; --leading-h2: 53px;
  --text-h3: 24px; --weight-h3: 600; --leading-h3: 31px;
  --text-body: 16px; --weight-body: 300; --leading-body: 24px;
  --text-small: 14px; --weight-small: 300; --leading-small: 20px;
  --radius: 8px;
  --radius-button: 12px;
  --radius-card: 100px;
  --radius-pill: 9999px;
  --radius-sharp: 2px;
  --shadow-card: rgba(19, 19, 22, 0.7) 0px 1px 5px -4px, rgba(34, 42, 53, 0.08) 0px 0px 0px 1px, rgba(34, 42, 53, 0.05) 0px 4px 8px 0px;
  --shadow-subtle: rgba(0, 0, 0, 0) 0px 1px 3px 0px, rgba(0, 0, 0, 0) 0px 0px 2px 0px;
  --focus-ring: 1px auto rgb(16, 16, 16);
}

/* their own tokens, verbatim from the site's :root */
:root {
  --sj-tw-ring-color: rgba(59,130,246,.5);
  --sj-tw-ring-offset-color: #fff;
  --sj-tw-ring-offset-width: 0px;
}
/* fonts: Cal Sans may be proprietary — safe free fallback: Newsreader (Google Fonts). Inter — free, on Google. */