Liveblocks UI Skills

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

When to Apply

Reference these guidelines when:

• Building dark-mode interfaces

• Creating Liveblocks-inspired design systems

• Implementing UIs with Inter font and 4px grid

Colors

• MUST use dark backgrounds (lightness < 20) for primary surfaces - detected lightness: 0

• MUST use #000000 as page background (surface-base )

• SHOULD reduce color palette (currently 11 colors detected)

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

Semantic Tokens

Token HEX RGB Usage

surface-base

#000000 rgb(0,0,0) Page background

surface-raised

#E5E5E5 rgb(229,229,229) Cards, modals, raised surfaces

surface-overlay

#FEFEFE rgb(254,254,254) Overlays, tooltips, dropdowns

text-primary

#818181 rgb(129,129,129) Headings, body text

text-secondary

#5B595A rgb(91,89,90) Secondary, muted text

text-tertiary

#B5B5B5 rgb(181,181,181) Additional text

border-default

#EAEAEA rgb(234,234,234) Subtle borders, dividers

Typography

• MUST use Inter as primary font family

• SHOULD use single font family for consistency

• MUST use 54px / 700 for primary headings

• MUST use 19px / 400 for body text

• MUST limit font weights to: medium, regular, bold

• 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 54px 700 #E9E9E9 1

body

Inter 19px 400 #818181 1

body-secondary

Inter 19px 400 #8E8E8E 1

body-secondary

Inter 18px 400 #737373 1

body-secondary

Inter 18px 500 #C4C4C4 1

body-secondary

Inter 17px 400 #707070 1

text-15px

Inter 15px 400 #8E8E8E 1

text-15px

Inter 15px 400 #747474 1

text-15px

Inter 15px 400 #777777 1

text-15px

Inter 15px 400 #797979 1

Typography Reference

Font Families:

• Inter (used 30x)

Font Sizes: 6px, 8px, 11px, 12px, 14px, 15px, 17px, 18px, 19px, 54px

Spacing

• MUST use 4px grid for spacing

• SHOULD use spacing from scale: 1px, 2px, 3px, 4px, 5px, 6px, 7px, 8px

• 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, 5px, 19px

• MUST use 1px border width consistently

• SHOULD use 3px 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, 5px, 19px

Layout

• MUST design for 1920px base viewport width

• SHOULD use consistent element widths: 36px, 48px, 1px, 8px, 47px

• 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: 1855px, height: 1080px

• Main Content: width: 1920px, height: 769px

• Main Content: width: 1920px, height: 559px

Components

Buttons

Variant Background Text Border Height Radius

Ghost transparent #6B6B6B 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 #E5E5E5 background

• List items: use #E5E5E5 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