Arc — decoded design system

arc.net · light · modern · custom · deep decode — measured live

Arc's design system, decoded live by Mozaika: measured color roles, type scale, buttons with real hover/focus states, motion and the brand's own tokens.

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

Decoded design system

Arc's decoded design system: background #FFFCEC, text #000000, accent #2702C2, link #3139FB, primary #2702C2; type scale h1 46px / h2 40px / body 16px; 8px spacing base; 0px base radius. The single interactive/action color is #2702C2 — used only on interactive or must-notice elements (buttons, links, key highlights), never on large fills.

Color roles

Using these colors

• Action color #2702C2 — the single interactive color; only on things you click or must notice, never large fills.
• primary, accent, button_bg are all #2702C2 — one role, not several (the action color).
• accent #2702C2 — 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 #3139FB — inline text links and link-styled controls.

Typography

• Heading: Marlin Soft
• Body: Segoe UI
• Mono: ABC Favorit Mono
• h1: 46px
• h2: 40px
• body: 16px

Spacing

• base unit: 8px
• scale: 3px, 4px, 6px, 8px, 10px, 12px, 16px, 20px, 24px, 32px

Radii

• base: 0px
• button: 10px

Shadow

rgba(0, 0, 0, 0.1) 0px 5px 5px 0px

Shadows (elevation)

• card: rgba(0, 0, 0, 0.1) 0px 5px 5px 0px

Motion

Micro-interactions run at 150ms (dominant) with ease.

• durations: 150ms · 200ms · 100ms
• easings: ease · ease-out
• animated properties: transform, background, box-shadow, opacity

Native design tokens

…and 103 more measured on the page.

Button states (measured)

• primary hover: box-shadow rgba(0, 0, 0, 0.2) 0px 7px 15px 0px · transform matrix(1.02, 0, 0, 1.02, 0, 0)
• primary focus: box-shadow rgba(0, 0, 0, 0.1) 0px 2px 6px 0px · outline 2px solid rgb(150, 196, 255) · transform matrix(1.02, 0, 0, 1.02, 0, 0)

Layout (measured)

• container max-width: 1440px
• nav: 36px

Motion choreography (measured)

Load order: div.marquee×2

Responsive (measured)

• breakpoints: 480px · 600px · 650px · 800px · 960px · 1075px
• mobile (390px): hero 32px · nav hamburger

Install it

Drop this measured system into any shadcn/Tailwind project in one command:

npx shadcn add mozaika.design/r/decode/arc.net

registry item · or query it over MCP: get_design_system("Arc")

Export: DESIGN.md

# Arc — Design System

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

## Colors

| Role | Value |
|------|-------|
| bg | `#FFFCEC` |
| surface | `#EFECDD` |
| border | `#D8D6C8` |
| text | `#000000` |
| text_muted | `#605F59` |
| primary | `#2702C2` |
| accent | `#2702C2` |
| link | `#3139FB` |
| button_bg | `#2702C2` |
| button_text | `#FFFFFF` |

**Using these colors**

- **Action color** `#2702C2` — the single interactive color; it appears only on things you click or must notice (buttons, key highlights), never on large fills or backgrounds.
- `primary`, `accent`, `button_bg` are all `#2702C2` — one role, not several (your action color).
- **accent** `#2702C2` — 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** `#3139FB` — inline text links and link-styled controls.
- **Page coverage** (full-page screenshot pixels): `#3E45FA` 48.7% · `#CC97A7` 13.7% · `#F7EDEB` 10.8% · `#CCD1D0` 10.3%

## Typography

- Heading: **Marlin Soft** _(free fallback: Newsreader)_
- Body: **Segoe UI** _(free fallback: Newsreader)_
- Mono: **ABC Favorit Mono** _(measured)_

| Role | Size / weight · line-height · tracking |
|------|------------------------------------------|
| hero | 46px / 700 · lh 42px · tracking -1.82px |
| h2 | 40px / 700 · lh 39px · tracking -1.6px |
| h3 | 36px / 700 · lh 36px · tracking -0.72px |
| body | 16px / 700 |
| small | 14px / 500 · lh 29px · tracking -0.28px |
| eyebrow | 12px / 700 · tracking 0.6px |

- Weight ladder: 400 · 500 · 600 · 700 — use these exact measured weights, not the 400/600 defaults.

> **Fonts —** Marlin Soft may be proprietary — safe free fallback: Newsreader (Google Fonts). Segoe UI may be proprietary — safe free fallback: Newsreader (Google Fonts).

## Spacing
- base unit: 8px (inferred from the measured scale)
- measured scale: 3px, 4px, 6px, 8px, 10px, 12px, 16px, 20px, 24px, 32px — snap all gaps/padding to these
- section rhythm: 128px top/bottom padding per section (measured)

## Radius
- base: 0px
- button: 10px
- card: 8px

## Buttons

| Button | Fill / text | Border | Radius | Padding | Font | Shadow |
|--------|-------------|--------|--------|---------|------|--------|
| primary | `#2702C2` / `#FFFFFF` | none | 10px | 8px 0px 8px 0px | 600 14px / -0.14px | rgba(0, 0, 0, 0.1) 0px 5px 5px 0px |
| secondary | `#FFFFFF` / `#2702C2` | none | 10px | 8px 0px 8px 0px | 600 14px / -0.14px | rgba(0, 0, 0, 0.1) 0px 5px 5px 0px |

**States (measured, not guessed)**

- primary hover: box-shadow `rgba(0, 0, 0, 0.2) 0px 7px 15px 0px` · transform `matrix(1.02, 0, 0, 1.02, 0, 0)`
- primary focus: box-shadow `rgba(0, 0, 0, 0.1) 0px 2px 6px 0px` · outline `2px solid rgb(150, 196, 255)` · transform `matrix(1.02, 0, 0, 1.02, 0, 0)`
- secondary hover: box-shadow `rgba(0, 0, 0, 0.2) 0px 7px 15px 0px` · transform `matrix(1.02, 0, 0, 1.02, 0, 0)`
- transition: `transform 0.15s ease`

## Shadows (elevation)
- card: `rgba(0, 0, 0, 0.1) 0px 5px 5px 0px`
- button: `rgba(0, 0, 0, 0.1) 0px 5px 5px 0px`

## Motion
- durations: 150ms (dominant) · 200ms · 100ms
- easings: `ease` (dominant) · `ease-out`
- animated properties: transform, background, box-shadow, opacity

Micro-interactions use the dominant duration + easing; nothing on the page animates slower than the longest duration above — don't invent springier motion.

## Their own tokens (verbatim from :root)

| Token | Value |
|-------|-------|
| `--colors-primary7` | `#CF3828` |
| `--colors-focusOutline` | `#96C4FF` |
| `--colors-highContrast` | `#000` |
| `--colors-primary6` | `#FA4531` |
| `--colors-students-light_grey-hover` | `#D7D6C4` |
| `--colors-brandOffwhite` | `#FFFCEC` |
| `--colors-secondary4` | `#008279` |
| `--colors-secondary2` | `#00C9C3` |
| `--colors-brandDeepBlue` | `#2404AA` |
| `--colors-lowContrast` | `#FFF` |
| `--colors-students-light_green` | `#D3E081` |
| `--colors-primary4` | `#FC8279` |

_…and 101 more measured on the page._

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

## Layout (measured)
- container max 1440px
- nav: 36px

| Section (y) | Height | Cols | Gap | Pad y | Split |
|---|---|---|---|---|---|
| 90 | 617 | — | — | 72/0 | — |
| 707 | 920 | — | — | 0/0 | — |
| 1822 | 1080 | — | — | 0/0 | — |
| 2902 | 1041 | — | — | 0/0 | — |
| 3942 | 1041 | — | — | 0/0 | — |

## Motion choreography (measured)
Load order: `div.marquee`×2 @0ms

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

## Components (measured)
- link: #FFFADD · no underline

## Responsive (measured)
- breakpoints: 480px · 600px · 650px · 800px · 960px · 1075px
- mobile (390px): hero 32px · body 16px · nav: hamburger

## 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.

← All decoded design systems

An automated reading of Arc's publicly-visible CSS (colors, fonts, spacing, motion) — not affiliated with arc.net. No screenshots stored. Removal requests: hello@mozaika.design.