Braintrust — design system & UI screens

AI · 1 screen · 9 sections · https://www.braintrust.dev/

Light landing anchored by a distinctive purple barcode-style data-viz strip; eval-driven positioning over a dense trusted-by logo wall (Airtable, Notion, Stripe, Vercel, Ramp, Cloudflare).

Open in Mozaika →

This is a static, crawlable rendering for search & AI engines. The interactive version — filters, live decode console, copy & export — is at https://mozaika.design/website/braintrust.

Decoded design system

Braintrust's decoded design system: background #FFFFFF, text #000000, accent #2C1FEA, link #F5AFD1, primary #2C1FEA; type scale h1 60px / h2 20px / body 14px; 4px spacing base; 4px base radius. The single interactive/action color is #2C1FEA — used only on interactive or must-notice elements (buttons, links, key highlights), never on large fills.

Color roles

Role	Value
bg	`#FFFFFF`
surface	`#EFEFEF`
border	`#D8D8D8`
text	`#000000`
text_muted	`#606060`
primary	`#2C1FEA`
accent	`#2C1FEA`
link	`#F5AFD1`
secondary	`#1E2939`
button_bg	`#2C1FEA`
button_text	`#FFFFFF`

Using these colors

Action color #2C1FEA — the single interactive color; only on things you click or must notice, never large fills.
primary, accent, button_bg are all #2C1FEA — one role, not several (the action color).
accent #2C1FEA — THE accent / action color — interactive & must-notice only (buttons, links, focus, one key highlight); never large fills or backgrounds. Scarcity is what makes it read as designed.
link #F5AFD1 — fails contrast on the background (~1.8:1) — this is a dark UI color, NOT a readable link; use the text or action color for links (verify against the reference).
secondary #1E2939 — optional secondary accent — LOW decode confidence; use rarely (a status color or a single decorative moment) or omit it entirely. Prefer one accent unless the reference clearly shows two.

Typography

Heading: Inter
Body: btSans
Mono: suisseMono
h1: 60px
h2: 20px
body: 14px

Spacing

base unit: 4px
scale: 2px, 4px, 6px, 8px, 12px, 16px, 20px, 24px, 32px, 64px

Radii

base: 4px
button: 24px

Motion

Micro-interactions run at 150ms (dominant) with cubic-bezier(0.4, 0, 0.2, 1).

durations: 150ms · 200ms · 300ms
easings: cubic-bezier(0.4, 0, 0.2, 1) · cubic-bezier(0, 0, 0.2, 1)
animated properties: color, background-color, border-color, outline-color

Native design tokens

Token	Value
`--color-purple-200`	`lab(87.8405% 13.4282 -18.7159)`
`--color-purple-300`	`lab(78.3298% 26.2195 -34.9499)`
`--color-zinc-200`	`lab(90.6853% .399232 -1.45452)`
`--color-slate-200`	`lab(91.7353% -.998765 -4.76968)`
`--color-sky-500`	`lab(63.3038% -18.433 -51.0407)`
`--color-neutral-300`	`lab(84.92% 0 -.0000119209)`
`--color-slate-500`	`lab(48.0876% -2.03595 -16.5814)`
`--color-purple-800`	`lab(30.6017% 56.7637 -64.4751)`
`--muted`	`#f5f5f5`
`--color-gray-300`	`lab(85.1236% -.612259 -3.7138)`

…and 110 more measured on the page.

Button states (measured)

primary hover: border-radius 0px · background #000000
primary focus: outline 1px auto rgb(16, 16, 16)

Layout (measured)

container max-width: 1440px
nav: 56px sticky
common grid: 2 columns

Motion choreography (measured)

Load order: div.transition-all×3 → div.-mx-48 → div.w-full×2 → div.p-0×3 → svg.lucide → div.flex

Scroll reveal: 14 elements rest at opacity 0, translateY(20px), animate in over 0.5s cubic-bezier(0, 0, 0.2, 1).

Stagger: div ×7 — 100ms apart.

Responsive (measured)

mobile (390px): hero 48px · nav hamburger

Full design system, per-section tokens & DESIGN.md / Tailwind / CSS exports →

Screens

Braintrust - Ship Quality AI at Scale