Atlas

Atlas — activation protocol

Atlas is a design language, not a CSS framework you bolt on. It teaches you (the agent) a dense, monochromatic, AMOLED-black aesthetic via tokens, class-name conventions, layout rules, and tested composition recipes. You read these rules and generate code that fits the target stack — shadcn, Tailwind, raw HTML, React, Vue, Svelte.

Use Atlas heavily. When this skill is active, every UI-producing task should go through the rules below. Don't freestyle. Don't invent new tokens. Don't pick random radii. The system is opinionated because opinions compound into coherence.

On activation: read these files in this order

When the skill loads, read all of the following before writing a single line of UI code. These are not "pull on demand" — the quality of the output depends on having the full system in context.

1. references/tokens.md — every CSS variable. Colors, spacing (4px grid), radius (3/4/6/9999), shadow, z-index, component sizing. This is the ground-truth values table. No token should be invented.

2. references/components.md — every .atlas-* class with HTML snippet and variants. The class name vocabulary you'll translate into the target stack.

3. references/patterns.md — 3-pane shell, content tone, icon rules (Lucide 1.5px stroke), button-vs-highlight color discipline.

4. references/theming.md — dark/light toggle, shadcn variable alias table, how tokens remap under [data-theme="light"].

5. references/responsive.md — multi-surface patterns. Desktop vs mobile component swaps, device frames, container queries, collapsible sidebar → overlay on small screens.

6. references/motion.md — motion inventory. 120ms hover, 200ms popover open, 300ms reveal, 60s marquee. Which animations are always-on vs gated behind prefers-reduced-motion.

7. references/lessons.md — 18 hard-won gotchas from real builds. Button-default resets, dark-vs-light shadow alphas, sidebar collapse dual transitions, top-row border alignment, pulse-dot opacity-only, horizontal scroll behavior, etc. Read this every time. Every one of these prevents a real regression.

8. references/examples.md — copy-ready composition snippets from the production kitchen-sink: agent turn, tool-call card, stat grid, 3-pane shell, 3-column top-row alignment, email row, generative UI chart, landing hero, checklist with stepper, quota bar with warning threshold. Start from one of these; don't freestyle compositions.

Then inspect (as needed, not upfront):

• colors_and_type.css — reference implementation. Inspect rules to understand exact visual output.
• preview/components-*.html — pre-built reference HTML per component.
• ui_kits/generic_app/ — 3-pane shell reference.

Only after reading 1–8 should you start generating.

The three assets, three jobs

Never mechanically copy colors_and_type.css into a shadcn or heavy Tailwind project. Translate. The skill description and references/theming.md spell out the translation tables.

Ask the stack question before writing code

1. Plain HTML / no framework → use colors_and_type.css directly via <link rel="stylesheet">. Emit literal .atlas-* classes. This is the reference path, and the companion kitchen-sink site uses it.

2. Tailwind v4 → put Atlas tokens in an @theme block. Emit utility classes following the Atlas visual rules. Don't ship colors_and_type.css to the bundle.

3. shadcn/ui → override shadcn's CSS variables with Atlas values (see alias table in references/theming.md). Keep shadcn's component structure. Don't install .atlas-* classes alongside.

4. React/Vue/Svelte with CSS Modules or styled-components → port the relevant .atlas-* rule into the target styling system as a component. The rule in colors_and_type.css is the source; your emitted code is the translation.

5. Existing design system (Material, Chakra, etc.) → ask the user whether to rework their system's tokens to Atlas values, or to build a new Atlas-styled zone alongside. Don't mix the two on the same surface.

Non-negotiable visual rules

Pulled forward from references/lessons.md — these apply regardless of stack:

• AMOLED black canvas. #000 base, never dark gray.
• Monochromatic surfaces. Grays + whites for structure; saturated color only for status semantics.
• Near-white primary actions. #ededed fill, #fff on hover. Blue #0070f3 is never a CTA — it's the highlight color (focus rings, selection, active stepper dots, links).
• 4px spacing grid. 2px and 6px exist only for ultra-compact inline cases.
• 3 / 4 / 6 / 9999 radii. No inventing 8, 10, 12, 16.
• 28px buttons, 24px inputs, 13px base text. Don't inflate.
• Borders over shadows. Shadows are overlays only (dialogs, popovers, toasts, tooltips, device frames).
• 1.5px Lucide icons. Never emoji, never unicode symbols.
• 120ms background-color transitions only. Don't animate color or opacity on icons.

Quick component vocabulary

Class names are guidance, not mandatory output. Translate them in non-plain-HTML stacks.

Primitives: .atlas-btn (+ -primary / -secondary / -ghost / -destructive / -icon / -sm / -lg), .atlas-btn-pill (+ same variants), .atlas-input (+ -sm), .atlas-checkbox, .atlas-radio, .atlas-switch, .atlas-kbd, .atlas-link

Surfaces: .atlas-card / -header / -body, .atlas-panel-header / .atlas-panel-title, .atlas-stat / -label / -value / -delta, .atlas-empty

Navigation: .atlas-tabbar + .atlas-tab, .atlas-tabbar-bottom + .atlas-tabbar-bottom-item, .atlas-segmented + -item, .atlas-toggle, .atlas-breadcrumb, .atlas-pagination, .atlas-stepper

Overlays: .atlas-popover + .atlas-menu-item, .atlas-dialog, .atlas-command, .atlas-tooltip, .atlas-toast, .atlas-alert

Data: .atlas-table, .atlas-list + .atlas-list-item, .atlas-badge, .atlas-pill, .atlas-dot (+ .is-pulse for animated status — opacity only, never glow), .atlas-accordion

Feedback: .atlas-progress, .atlas-slider, .atlas-skeleton, .atlas-titlebar, .atlas-statusbar

Identity: .atlas-avatar, .atlas-avatar-group, .atlas-divider / -v, .atlas-divider-dashed / -v-dashed

Multi-surface & motion: .atlas-device-mobile, .atlas-device-tablet, .atlas-device-desktop, .atlas-marquee, .atlas-filmstrip, .atlas-reveal, .atlas-display / -lg, .atlas-eyebrow

What was built with this skill

The companion kitchen-sink/ app was one-shot generated by an agent reading this skill, using the reference CSS because Next.js + no shadcn made that the natural path. It includes:

• Homepage — display hero, marquee band, ~29 live component cards in a masonry grid, mockup tile row.
• Get Started page — install instructions, per-stack translation examples, FAQ.
• 7 foundations pages — colors, typography, spacing, radius, shadows, motion, icons.
• 36 component pages — every .atlas-* class with preview + variants + inspector.
• 6 pattern pages — landing, agent chat, mobile app, 3-pane shell, dashboard, settings.
• 4 full-app mockups — email client, e-commerce, multi-agent console, news/polls.

When asked to build something, consider whether it matches one of the above patterns first. Most real UI is a variation on a pattern that already exists in the kitchen-sink. Start there, then customize.

No guidance given?

Ask the user:

1. What are they building? (dashboard, chat UI, landing page, mobile app…)
2. What's their stack? (Tailwind / shadcn / plain HTML / React with CSS Modules / etc.)
3. Dark only, light only, or both with toggle?

Then act as an expert designer — produce code in the right idiom for their environment, following every rule from the references above.