Railway UI Skills

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

When to Apply

Reference these guidelines when:

• Building dark-mode interfaces

• Creating Railway-inspired design systems

• Implementing UIs with Inter font and 4px grid

Colors

• MUST use dark backgrounds (lightness < 20) for primary surfaces - detected lightness: 7

• MUST use #0F0E14 as page background (surface-base )

• MUST use #0B1025 for primary actions and focus states (accent )

• SHOULD reduce color palette (currently 19 colors detected)

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

Semantic Tokens

Token HEX RGB Usage

surface-base

#0F0E14 rgb(15,14,20) Page background

surface-raised

#1E1C25 rgb(30,28,37) Cards, modals, raised surfaces

surface-overlay

#0B1025 rgb(11,16,37) Overlays, tooltips, dropdowns

text-primary

#85848A rgb(133,132,138) Headings, body text

text-secondary

#48464F rgb(72,70,79) Secondary, muted text

text-tertiary

#A09FA5 rgb(160,159,165) Additional text

border-default

#15181F rgb(21,24,31) Subtle borders, dividers

accent

#0B1025 rgb(11,16,37) Primary actions, links, focus

Typography

• MUST use Inter as primary font family

• SHOULD use single font family for consistency

• MUST use 54px / extra_bold for primary headings

• MUST use 11px / 300 for body text

• SHOULD reduce font weights (currently 4 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 54px extra_bold #E9ECED 1

text-19px

Inter 19px 400 #90959E 1

text-19px

Inter 19px 500 #C6C5CA 1

text-18px

Inter 18px 500 #DACEE6 1

text-15px

Inter 15px 400 #5C3C82 1

text-14px

Inter 14px 400 #C0C4C7 1

text-14px

Inter 14px 400 #8C929B 1

text-14px

Inter 14px 400 #A5A4AA 1

text-14px

Inter 14px 400 #8D8C93 1

text-14px

Inter 14px 400 #95949B 1

Typography Reference

Font Families:

• Inter (used 74x)

Font Sizes: 7px, 8px, 9px, 10px, 11px, 12px, 13px, 14px, 15px, 18px, 19px, 54px

Spacing

• MUST use 4px grid for spacing

• SHOULD use spacing from scale: 1px, 2px, 3px, 4px, 5px, 8px, 12px, 14px

• SHOULD use 2px 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: 0px, 2px, 3px, 4px, 5px, 6px, 8px, 10px

• SHOULD limit border widths to: 1px, 2px, 6px

• 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: 0px, 2px, 3px, 4px, 5px, 6px, 8px, 10px

Layout

• MUST design for 1920px base viewport width

• SHOULD use consistent element widths: 81px, 8px, 72px, 62px, 708px

• 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: 1920px, height: 1080px

• Main Content: width: 1710px, height: 958px

• Main Content: width: 1853px, height: 724px

• Header: height: 53px

• Header: height: 52px

Components

Buttons

Variant Background Text Border Height Radius

Ghost transparent #2C2B33 none

Interactive States

Focus

• MUST use 2px outline with accent color (#0B1025 )

• MUST use 2px outline-offset

• NEVER remove focus indicators

Hover

• Buttons (primary): lighten background by 10%

• Buttons (secondary): use #1E1C25 background

• List items: use #1E1C25 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