design-guidelines

Even Hub G2 Design Guidelines

Display Constraints

• Resolution: 576 x 288 pixels per eye
• Color depth: 4-bit greyscale — 16 levels of green
• White pixels appear as bright green; black pixels are off (transparent)
• No background color or fill color property
• No CSS, no flexbox, no DOM — UI is built from absolute-positioned pixel containers
• Max 4 image containers and 8 other containers per page

Container Limits

• Max 12 containers total (8 text/list + 4 image)
• Exactly one container must have isEventCapture: 1
• containerID must be unique per page (integer)
• containerName must be unique per page (string, max 16 characters)
• Stacking order via zOrderIndex (SDK 0.0.12+) — all-or-nothing per page, unique values, larger = front; when omitted everywhere, declaration order determines overlap

Font & Text

• Single LVGL font baked into firmware
• Not monospaced
• No font selection, no font size control, no bold/italic
• Characters outside the font are silently skipped
• Text wraps at container width
• Use \n for line breaks
• ~400-500 characters fill a full-screen text container
• Unicode supported within the firmware font set

Common UI Patterns

Pattern	How
Fake buttons	Prefix text with > as cursor indicator
Selection highlight	Toggle borderWidth on individual text containers
Multi-row layout	Stack multiple text containers vertically (e.g., 3 containers at 96px height)
Progress bars	Unicode block characters: ━ (filled) and ─ (empty), or █▇▆▅▄▃▂▁
Page flipping	Pre-paginate text at ~400-500 char boundaries, rebuild on scroll events
"Centering" text	Manually pad with spaces (no text alignment support)

Icon Design Principles

• Design at native resolution — work at actual pixel size (e.g., 24x24). Avoid designing large and scaling down.
• Keep it simple — aim for immediately recognizable silhouettes with minimal internal detail.
• Test on hardware — green-tinted greyscale rendering differs from your monitor. Always verify legibility on actual display or simulator with glow enabled.

Useful Unicode Characters

Use Case	Characters
Progress bars	━ ─ █▇▆▅▄▃▂▁
Navigation	▲△▶▷▼▽◀◁
Selection	●○ ■□ ★☆
Borders	╭╮╯╰ │─ (box drawing set)
Card suits	♠♣♥♦

Full supported glyph tables: https://github.com/nickustinov/even-g2-notes

Image Containers

• Width: 20–288 px, Height: 20–144 px
• 4-bit greyscale
• Placeholder on creation — must call updateImageRawData to display content
• No concurrent image sends — wait for each to complete
• Use simple/flat colors; glasses have limited memory

Phone-Side App UI (Flutter WebView host)

The glasses render monochrome green on black, but the Flutter WebView that hosts your plugin on the phone has its own visual identity. Match the Even app design system when building phone-side config / settings / library screens so your plugin feels native inside Even Hub.

Color tokens

Token	Light	Dark	Use
--color-text	#232323 (TC-1st)	#FFFFFF	Primary text
--color-text-dim	#7B7B7B (TC-2nd)	#8A8A8A	Secondary text, timestamps, captions
--color-bg	#FFFFFF (BC-1st)	#111111	Page background
--color-surface	#EEEEEE (BC-3rd)	#1A1A1A	Card / row background
--color-input-bg	rgba(35,35,35,0.08)	rgba(255,255,255,0.08)	Search bar, input fields
--color-accent	#FEF991	#FEF991	Brand accent (sparingly — buttons, highlights)
--color-text-on-accent	#FFFFFF	#FFFFFF	Text on accent backgrounds

Brand rules:

• #FEF991 is Even brand yellow — use only for accent (buttons, highlights), never as a page background
• #3CFA44 is glasses-display green — use ONLY on the G2 display, NEVER in phone-side UI

Typography

Primary: FK Grotesk Neue (negative letter-spacing for a tight, editorial feel). Fallback: Source Han Sans for CJK, system sans for everything else.

Style	Size	Weight	Letter-spacing
Display	34 px	700	-0.02em
Title	24 px	600	-0.02em
Subtitle	18 px	500	-0.01em
Body	16 px	400	-0.01em
Caption	13 px	400	0
Label	11 px	500	0.04em (uppercase)

Spacing

Use a 4/8 px grid: 4 8 12 16 24 32 48 64. Card padding: 16. Section spacing: 24–32. Screen edge padding: 20.

Figma Design Guidelines

Official design guidelines covering layout principles, component patterns, interaction models, and visual standards: https://www.figma.com/design/X82y5uJvqMH95jgOfmV34j/Even-Realities---Software-Design-Guidelines--Public-?node-id=2922-80782

Community Resources

• even-g2-notes (GitHub: https://github.com/nickustinov/even-g2-notes) — architecture deep-dives, full Unicode glyph tables, SDK quirks, error codes, reference implementations: chess, reddit reader, weather, Tesla vehicle status, pong, snake
• even-toolkit (GitHub: https://github.com/fabioglimb/even-toolkit, npm: even-toolkit) — 55+ React components, 191 pixel-art icons, design tokens, glasses SDK bridge utilities (useGlasses hook, buildActionBar, mapGlassEvent, canvas renderer, PNG utils, pagination helpers)
• Discord: https://discord.gg/Y4jHMCU4sv — developer community for support, bug reports, discussion

Task

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