Design language comparison
Plain vs PostHog
Plain runs a dark-canvas system while PostHog chose light, and they pair different display families (sans-serif vs Open Runde). Beyond surface, motion divides them — Plain is subtle, PostHog is expressive.
Palette · side by side
Up to 8 dominant swatches eachSide A · dark
Plain
Full Page
#000000
foreground
#0a2414
brand
#17b267
brand
#0000ee
accent
#f3fbe9
background
#ffffff
background
#1f1f28
foreground
#f9f6f1
background
Side B · light
PostHog
Full Page
#4d4f46
foreground
#000000
foreground
#374151
foreground
#9ea096
neutral
#111827
foreground
#65675e
foreground
#f7a501
accent
#bfc1b7
neutral
Typography · side by side
Primary family + weight ladder + sampleSide A · dark
Plain
Full Page
- Display
- ABC Favorit Regular
- Body
- sans-serif
- Mono
- Geist Mono
- Weights
- 400
Sample
The quick brown fox jumps over the lazy dog.
1234567890 — Body sample renders in the captured family if your browser has it; otherwise system fallback signals the weight ladder.
Side B · light
PostHog
Full Page
- Display
- Open Runde
- Body
- IBM Plex Sans Variable
- Mono
- ui-monospace
- Weights
- 400 · 500 · 600 · 700 · 800
Sample
The quick brown fox jumps over the lazy dog.
1234567890 — Body sample renders in the captured family if your browser has it; otherwise system fallback signals the weight ladder.
Spacing scale · side by side
Base unit + first 8 scale valuesSide A · dark
Plain
Full Page
- Base unit
- 4 px
- Container max
- 1200 px
Side B · light
PostHog
Full Page
- Base unit
- 4 px
- Container max
- 320 px
Motion vocabulary · side by side
Level + durations + easingsSide A · dark
Plain
Full Page
- Level
- subtle
- Libraries
- Framer Motion
Durations
Easings
Side B · light
PostHog
Full Page
- Level
- expressive
- Libraries
- —
Durations
Easings
Palette & spacing overlap
Their palettes share 10% of swatches at the dominant tier — a quiet signal both teams drew from the same neutral library before applying brand accents. Their spacing scales overlap by 50% (4, 8, 10, 12, 20 px shared) — a rhythm any agent can transfer between the two systems with minimal recalibration.
Shared swatches (2)
Curator verdict
Pick a side. Mixing Plain's dark-first canvas with PostHog's expressive motion vocabulary produces visual whiplash. Adopt one system as your primary, study the other for individual technique transfers (e.g. Plain's spacing, PostHog's shadow).