arc-ui-skills

Arc 的 UI 设计系统。适用于在构建界面时，以 Arc 的美学风格为灵感——采用浅色模式、Inter 字体、4px 网格。

SKILL.md

--- frontmatter

name: arc-ui-skills
description: Arc's UI design system. Use when building interfaces inspired by Arc's aesthetic - light mode, Inter font, 4px grid.
license: MIT
metadata:
  author: design-skills
  version: "1.0.0"
  source: https://arc.net

Arc UI Skills

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

When to Apply

Reference these guidelines when:

•Building light-mode interfaces
•Creating Arc-inspired design systems
•Implementing UIs with Inter font and 4px grid

Colors

•SHOULD use light backgrounds for primary surfaces
•MUST use #E4E4E4 as page background (surface-base)
•MUST use #6FADE2 for primary actions and focus states (accent)
•SHOULD reduce color palette (currently 26 colors detected)
•MUST maintain text contrast ratio of at least 4.5:1 for accessibility

Semantic Tokens

Token	HEX	RGB	Usage
`surface-base`	#E4E4E4	rgb(228,228,228)	Page background
`surface-raised`	#1B00B5	rgb(27,0,181)	Cards, modals, raised surfaces
`surface-overlay`	#FEFEFD	rgb(254,254,253)	Overlays, tooltips, dropdowns
`text-primary`	#BFAFEA	rgb(191,175,234)	Headings, body text
`text-secondary`	#513EA3	rgb(81,62,163)	Secondary, muted text
`text-tertiary`	#E0DCEA	rgb(224,220,234)	Additional text
`border-default`	#1902BE	rgb(25,2,190)	Subtle borders, dividers
`accent`	#6FADE2	rgb(111,173,226)	Primary actions, links, focus
`warning`	#FEFEFD	rgb(254,254,253)	Warning states, cautions

Typography

•MUST use Inter as primary font family
•SHOULD use single font family for consistency
•MUST use 53px / 700 for primary headings
•MUST use 22px / 500 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	53px	700	#E4E3EF	1
`text-36px`	Inter	36px	700	#2D2C2B	1
`body`	Inter	22px	500	#C7C7C7	1
`text-19px`	Inter	19px	400	#666664	1
`text-14px`	Inter	14px	semi_bold	#E0DCEA	1
`text-13px`	Inter	13px	400	#37556A	1
`text-13px`	Inter	13px	300	#C0C2C2	1
`text-13px`	Inter	13px	400	#AEACF0	1
`text-12px`	Inter	12px	400	#BFAFEA	1
`text-12px`	Inter	12px	400	#513EA3	1

Typography Reference

Font Families:

•Inter (used 28x)

Font Sizes: 5px, 6px, 8px, 9px, 10px, 11px, 12px, 13px, 14px, 19px, 22px, 36px, 53px

Spacing

•MUST use 4px grid for spacing
•SHOULD use spacing from scale: 1px, 2px, 3px, 4px, 5px, 6px, 7px, 10px
•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: 2px, 3px, 4px, 5px, 6px, 7px, 8px, 9px, 21px, 22px
•SHOULD use 21px+ radius for pill-shaped elements
•SHOULD limit border widths to: 1px, 2px
•SHOULD use 7px 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: 2px, 3px, 4px, 5px, 6px, 7px, 8px, 9px, 21px, 22px

Layout

•MUST design for 1920px base viewport width
•SHOULD use consistent element widths: 69px, 11px, 10px, 70px, 15px
•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: 602px
•Main Content: width: 1920px, height: 613px
•Header: height: 99px

Components

Buttons

Variant	Background	Text	Border	Height	Radius
Ghost	transparent	#BFAFEA	none	-	-

Interactive States

Focus

•MUST use 2px outline with accent color (#6FADE2)
•MUST use 2px outline-offset
•NEVER remove focus indicators

Hover

•Buttons (primary): lighten background by 10%
•Buttons (secondary): use #1B00B5 background
•List items: use #1B00B5 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