Monzo UI Skills

Opinionated constraints for building Monzo-style interfaces with AI agents.

When to Apply

Reference these guidelines when:

• Building light-mode interfaces

• Creating Monzo-inspired design systems

• Implementing UIs with Inter font and 4px grid

Colors

• SHOULD use light backgrounds for primary surfaces

• MUST use #FFFFFF as page background (surface-base )

• SHOULD reduce color palette (currently 15 colors detected)

• MUST maintain text contrast ratio of at least 4.5:1 for accessibility

Semantic Tokens

Token HEX RGB Usage

surface-base

#FFFFFF rgb(255,255,255) Page background

surface-raised

#C1C5C8 rgb(193,197,200) Cards, modals, raised surfaces

surface-overlay

#DEDEDE rgb(222,222,222) Overlays, tooltips, dropdowns

text-primary

#606366 rgb(96,99,102) Headings, body text

text-2

#494D50 rgb(73,77,80) Additional text

text-secondary

#BEC4C7 rgb(190,196,199) Secondary, muted text

border-default

#8A8D8F rgb(138,141,143) Subtle borders, dividers

destructive

#ED4948 rgb(237,73,72) Error states, delete actions

Typography

• MUST use Inter as primary font family

• SHOULD use single font family for consistency

• MUST use 48px / 700 for primary headings

• MUST use 21px / extra_bold for body text

• SHOULD reduce font weights (currently 5 detected)

• MUST use text-balance for headings and text-pretty for body text

• SHOULD use tabular-nums for numeric data

• NEVER modify letter-spacing unless explicitly requested

Text Styles

Style Font Size Weight Color Count

heading-1

Inter 48px 700 #F0F1EE 1

body

Inter 21px extra_bold #ED4948 1

body-secondary

Inter 19px 300 #723C7E 1

text-17px

Inter 17px semi_bold #373737 1

text-16px

Inter 16px 400 #9EA0A2 1

text-15px

Inter 15px 400 #606366 1

text-15px

Inter 15px 400 #494D50 1

text-15px

Inter 15px 400 #BEC4C7 1

text-15px

Inter 15px 400 #C4C6BC 1

text-13px

Inter 13px 400 #4D4D4D 1

Typography Reference

Font Families:

• Inter (used 16x)

Font Sizes: 8px, 9px, 11px, 12px, 13px, 15px, 16px, 17px, 19px, 21px, 48px

Spacing

• MUST use 4px grid for spacing

• SHOULD use spacing from scale: 2px, 4px, 5px, 6px, 9px, 11px, 20px, 54px

• SHOULD use 5px as default gap between elements

• NEVER use arbitrary spacing values (use design scale)

• SHOULD maintain consistent padding within containers

Borders

• MUST use border-radius from scale: 3px, 4px, 6px, 16px, 25px

• SHOULD use 25px+ radius for pill-shaped elements

• MUST use 1px border width consistently

• SHOULD use 16px as default border-radius

• NEVER use arbitrary border-radius values (use design scale)

• SHOULD use subtle borders (1px) for element separation

Border Radius Reference

Scale: 3px, 4px, 6px, 16px, 25px

Layout

• MUST design for 1920px base viewport width

• SHOULD use consistent element widths: 12px, 116px, 43px, 60px, 299px

• SHOULD maintain text-heavy layout with clear hierarchy

• NEVER use h-screen , use h-dvh for full viewport height

• MUST respect safe-area-inset for fixed elements

• SHOULD use size-* for square elements instead of w-*

• h-*

Detected Layout Patterns

• Main Content: width: 1470px, height: 870px

• Main Content: width: 1455px, height: 762px

• Header: height: 82px

Components

Buttons

Variant Background Text Border Height Radius

Ghost transparent #494D50 none

Interactive States

Focus

• MUST use 2px outline with accent color (#5E6AD2 )

• MUST use 2px outline-offset

• NEVER remove focus indicators

Hover

• Buttons (primary): lighten background by 10%

• Buttons (secondary): use #C1C5C8 background

• List items: use #C1C5C8 background

Disabled

• MUST use opacity: 0.5

• MUST use cursor: not-allowed

Interaction

• MUST use an AlertDialog for destructive or irreversible actions

• SHOULD use structural skeletons for loading states

• MUST show errors next to where the action happens

• NEVER block paste in input or textarea elements

• MUST add an aria-label to icon-only buttons

Animation

• NEVER add animation unless it is explicitly requested

• MUST animate only compositor props (transform , opacity )

• NEVER animate layout properties (width , height , top , left , margin , padding )

• SHOULD use ease-out on entrance animations

• NEVER exceed 200ms for interaction feedback

• SHOULD respect prefers-reduced-motion

Performance

• NEVER animate large blur() or backdrop-filter surfaces

• NEVER apply will-change outside an active animation

• NEVER use useEffect for anything that can be expressed as render logic