Design System Analysis of Mercury

A fintech system that moves between a deep ink-violet night on the homepage and a pale near-white day on its product and pricing pages. One confident indigo action pill, soft translucent secondary pills, gently rounded cards and a quiet custom sans at unusually light weights.

01 — Foundations

Color Palette

Mercury Indigo

#5266eb

Open account pills, toggle, plan accents

On Primary

#ffffff

Labels on indigo

Periwinkle

#9cb4e8

20% fill of Contact sales pills on dark

Canvas

#fbfcfd

Light page background

Surface

#ffffff

Pricing tier columns, email field

Surface Tint

#fbfbff

Pricing card wrapper

Lavender

#edecfb

Light feature cards

Night

#171721

Nav, homepage canvas, footer

Night Raised

#1e1e2a

Dark feature cards

Ink

#28253b

Headlines and body on light

Ink Secondary

#554e7b

Descriptions, eyebrows on light

On Dark

#ededf3

Text on night surfaces

Fog

#c3c3cc

Secondary text on dark, light rules

Slate

#70707d

Row dividers on dark

02 — Foundations

Typography

arcadiaDisplay sets headlines and stats at weight 480; arcadia carries body (360–400), UI (420) and small caps eyebrows (500). Both are proprietary; Inter variable is shown as the substitute at the same light weights.

stat — 60px / 480 / 1.1 / 0
300K+
display — 52px / 480 / 1.1 / 0
Radically different banking
heading-1 — 42px / 480 / 1.15 / 0.42px
Compare our plans
heading-2 — 28px / 480 / 1.2 / 0.42px
IO credit card
lead — 24px / 480 / 1.2 / 0.48px
Mercury is built for entrepreneurs.
body-lg — 18px / 360 / 1.35 / 0
Confidently scale your team's spending.
body — 16px / 400 / 1.4 / 0
Powerful banking and finance essentials included with every account.
ui — 16px / 420 / 1 / 0
Open account
ui-sm — 14px / 420 / 1 / 0.07px
Expand all
eyebrow — 14px / 500 / 1 / 0.28px
COMPARE PLANS
legal — 12px / 400 / 1.4 / 0.24px
Mercury is a fintech company, not an FDIC-insured bank.
03 — Components

Button Variants

button-primary · indigo · 32pxOpen account

The one solid action per view. arcadia 420, 0×20px, 40px tall.

button-glass-dark · on night
Launch demo

Lavender-grey glass at 20% with a 36% hairline.

button-tint-dark · on night
Contact sales

Periwinkle at 20%.

button-tint-light · indigo 10%Explore demo
button-outline-light · grey-violet 10%Contact sales
button-small · 32px tallExpand all
button-icon-round · full
+❚❚
04 — Components

Cards & Surfaces

Mercury hits $5.2B valuation
+
IO credit card
feature-card-light · mockup + title + description
300K+
Entrepreneurs love us
4.9
stat-block
Compare plansAnnual Pricing (15% off)
Mercury
$0/mo.
Open account
Mercury Plus
$29.90/mo.
Open account
Mercury Pro
$299/mo.
Open account
“Mercury is built for entrepreneurs.”
quote-block · centered lead quote
LinearLovableElevenLabs
05 — Components

Form Elements

email-capture · text-input fused to button-primary
Enter your emailOpen account
toggle-switchAnnual Pricing (15% off)
accordion-row · 1px fog rules
Banking⌄
Sending and receiving money⌄
Treasury⌄
06 — Foundations

Spacing Scale

8px base. Cards pad 32px, pills 20px horizontally; sections breathe 80–128px apart.

xs
8px
sm
12px
md
16px
lg
20px
xl
24px
xxl
32px
huge
40px
section
80px
section-lg
128px
07 — Foundations

Border Radius

Softly rounded 12px cards, a 32px primary pill, 40px secondary pills and full circles for icon buttons and toggles.

0
none
4px
xs
8px
sm
12px
md
16px
lg
32px
xl
40px
pill
full
full
08 — Foundations

Elevation & Depth

Level 0 — flat. Cards lift by fill colour, not borders.
Level 1 — hair-thin layered shadow (2–9% ink). Pricing card and floating mockups.
09 — Responsive

Responsive Behavior

NameWidthKey changes
Desktop≥ 1200pxFull nav with dropdown pills; 3-up grids; split sections side by side
Laptop1024–1199pxNarrower container; fluid headline scaling
Tablet768–1023pxGrids go 2-up; split sections stack
Mobile< 768pxMenu nav; single-column cards; stacked pricing tiers
375
768
1024
1200

Touch targets: pills are 40px and the email capture 46px; pad hit areas to 44px on touch. Collapsing: dropdown pills fold into a menu while "Open account" stays; grids reflow 3 → 2 → 1; headlines scale fluidly; the email capture stacks field above button.