railway-ui-skills

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