Mercury — Design System

Name: Mercury design system
Creator: Mozaika
Keywords: design system, design tokens, Mercury, dark, tailwind

dark · professional · medium · tailwind · confidence 92%

Mercury is banking as a cinematic object: photographic hero worlds — a desk on a mountainside — over a porcelain near-white canvas, with one periwinkle blue (#5266EB) owning every action. Arcadia Display speaks at a soft 480 weight, so headlines feel engraved rather than shouted, while the real drama lives in UI numerals: balances, yields and approval chains rendered as jewel-box product screenshots. Buttons are full 32px pills, cards float on faint lavender fields, and dark sections arrive like night mode for emphasis. It reads as fintech styled by a luxury print magazine — calm, tactile, expensive — with the product itself as the photography.

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/mercury.

Tokens

Mercury's decoded design system: background #171721, text #ECECEE, accent #5266EB, link #353644, primary #323649; type scale h1 49px / h2 42px / body 18px; 8px spacing base; 4px base radius. The single interactive/action color is #5266EB — used only on interactive or must-notice elements (buttons, links, key highlights), never on large fills.

Color roles

Role	Value
bg	`#171721`
surface	`#23232D`
border	`#36363F`
text	`#ECECEE`
text_muted	`#9B9BA0`
primary	`#323649`
accent	`#5266EB`
link	`#353644`
secondary	`#5266EB`
button_bg	`#5266EB`
button_text	`#FFFFFF`

Using these colors

Action color #5266EB — the single interactive color; only on things you click or must notice, never large fills.
primary #323649, link #353644 are visually the same color (Δ8) — treat as one role (the action color).
accent, secondary, button_bg are all #5266EB — one role, not several (the action color).
accent #5266EB — 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.

Typography

Heading: Arcadia Display
Body: Arcadia
h1: 49px
h2: 42px
body: 18px

Spacing

base unit: 8px
scale: 4px, 8px, 12px, 16px, 24px, 32px, 48px, 64px

Radii

base: 4px
button: 32px

Per-section tokens (35)

Export: DESIGN.md

# Mercury — Design System

> dark, professional, medium, tailwind

Mercury is banking as a cinematic object: photographic hero worlds — a desk on a mountainside — over a porcelain near-white canvas, with one periwinkle blue (#5266EB) owning every action. Arcadia Display speaks at a soft 480 weight, so headlines feel engraved rather than shouted, while the real drama lives in UI numerals: balances, yields and approval chains rendered as jewel-box product screenshots. Buttons are full 32px pills, cards float on faint lavender fields, and dark sections arrive like night mode for emphasis. It reads as fintech styled by a luxury print magazine — calm, tactile, expensive — with the product itself as the photography.

## Colors

| Role | Value |
|------|-------|
| bg | `#171721` |
| surface | `#23232D` |
| border | `#36363F` |
| text | `#ECECEE` |
| text_muted | `#9B9BA0` |
| primary | `#323649` |
| accent | `#5266EB` |
| link | `#353644` |
| secondary | `#5266EB` |
| button_bg | `#5266EB` |
| button_text | `#FFFFFF` |

**Using these colors**

- **Action color** `#5266EB` — the single interactive color; it appears only on things you click or must notice (buttons, key highlights), never on large fills or backgrounds.
- `primary` `#323649`, `link` `#353644` are visually the same color (Δ8) — treat as one role.
- `accent`, `secondary`, `button_bg` are all `#5266EB` — one role, not several (your action color).
- **accent** `#5266EB` — 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.

## Typography

- Heading: **Arcadia Display** _(free fallback: Hanken Grotesk)_
- Body: **Arcadia** _(free fallback: Hanken Grotesk)_

| Role | Size / weight · line-height · tracking |
|------|------------------------------------------|
| hero | 49px / 480 · lh 54px |
| h2 | 42px / 480 · lh 48px · tracking 0.42px |
| h3 | 32px / 480 · lh 37px · tracking 0.48px |
| body | 16px / 420 · lh 22px |
| small | 12px / 480 · lh 17px · tracking 0.24px |

- Weight ladder: 360 · 400 · 420 · 480 — use these exact measured weights, not the 400/600 defaults.

> **Fonts —** Arcadia Display is proprietary — closest free match: Hanken Grotesk (Google). Load Hanken Grotesk; keep Arcadia Display first so licensed users still get it. Arcadia is proprietary — closest free match: Hanken Grotesk (Google). Load Hanken Grotesk; keep Arcadia first so licensed users still get it.

## Spacing
- base unit: 8px
- scale: 4px, 8px, 12px, 16px, 24px, 32px, 48px, 64px

## Radius
- base: 4px
- button: 32px
- card: 4px
- pill: 9999px

## Primary button
- bg `#5266EB` · text `#FFFFFF` · radius 32px

## 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.

Export: Tailwind v4 (@theme)

@theme {
  /* action color #5266EB — the one interactive color; buttons/links/emphasis only, never large fills. */
  --color-bg: #171721;
  --color-surface: #23232D;
  --color-border: #36363F;
  --color-text: #ECECEE;
  --color-text-muted: #9B9BA0;
  --color-primary: #323649;  /* a brand color — but the call-to-action uses #5266EB, not this. */
  --color-accent: #5266EB;  /* 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: #353644;  /* fails contrast on the background (~1.5:1) — this is a dark UI color, NOT a readable link; use the text or action color for links (verify against the reference). */
  --color-secondary: #5266EB;  /* same color as the action (see accent). */
  --color-button-bg: #5266EB;  /* primary-button fill — the main call-to-action color. */
  --color-button-text: #FFFFFF;
  /* fonts: Arcadia Display is proprietary — closest free match: Hanken Grotesk (Google). Load Hanken Grotesk; keep Arcadia Display first so licensed users still get it. Arcadia is proprietary — closest free match: Hanken Grotesk (Google). Load Hanken Grotesk; keep Arcadia first so licensed users still get it. */
  --font-heading: "Arcadia Display", "Hanken Grotesk", system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-body: "Arcadia", "Hanken Grotesk", system-ui, -apple-system, 'Segoe UI', sans-serif;
  /* measured weights: 360, 400, 420, 480 — use these, not 400/600 */
  --text-hero: 49px; --font-weight-hero: 480; --leading-hero: 54px;
  --text-h2: 42px; --font-weight-h2: 480; --leading-h2: 48px; --tracking-h2: 0.42px;
  --text-h3: 32px; --font-weight-h3: 480; --leading-h3: 37px; --tracking-h3: 0.48px;
  --text-body: 16px; --font-weight-body: 420; --leading-body: 22px;
  --text-small: 12px; --font-weight-small: 480; --leading-small: 17px; --tracking-small: 0.24px;
  --radius-base: 4px;
  --radius-button: 32px;
  --radius-card: 4px;
  --radius-pill: 9999px;
  --spacing-1: 4px;
  --spacing-2: 8px;
  --spacing-3: 12px;
  --spacing-4: 16px;
  --spacing-5: 24px;
  --spacing-6: 32px;
  --spacing-7: 48px;
  --spacing-8: 64px;
}

Export: CSS variables

:root {
  /* action color #5266EB — the one interactive color; buttons/links/emphasis only, never large fills. */
  --bg: #171721;
  --surface: #23232D;
  --border: #36363F;
  --text: #ECECEE;
  --text-muted: #9B9BA0;
  --primary: #323649;  /* a brand color — but the call-to-action uses #5266EB, not this. */
  --accent: #5266EB;  /* 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: #353644;  /* fails contrast on the background (~1.5:1) — this is a dark UI color, NOT a readable link; use the text or action color for links (verify against the reference). */
  --secondary: #5266EB;  /* same color as the action (see accent). */
  --button-bg: #5266EB;  /* primary-button fill — the main call-to-action color. */
  --button-text: #FFFFFF;
  --font-heading: "Arcadia Display", "Hanken Grotesk", system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-body: "Arcadia", "Hanken Grotesk", system-ui, -apple-system, 'Segoe UI', sans-serif;
  --text-hero: 49px; --weight-hero: 480; --leading-hero: 54px;
  --text-h2: 42px; --weight-h2: 480; --leading-h2: 48px; --tracking-h2: 0.42px;
  --text-h3: 32px; --weight-h3: 480; --leading-h3: 37px; --tracking-h3: 0.48px;
  --text-body: 16px; --weight-body: 420; --leading-body: 22px;
  --text-small: 12px; --weight-small: 480; --leading-small: 17px; --tracking-small: 0.24px;
  --radius: 4px;
  --radius-button: 32px;
  --radius-card: 4px;
  --radius-pill: 9999px;
}
/* fonts: Arcadia Display is proprietary — closest free match: Hanken Grotesk (Google). Load Hanken Grotesk; keep Arcadia Display first so licensed users still get it. Arcadia is proprietary — closest free match: Hanken Grotesk (Google). Load Hanken Grotesk; keep Arcadia first so licensed users still get it. */