version: "1.0.0" name: primer description: GitHub Primer look for polished-artifacts. Load after polished-artifacts:core when the user picks the Primer look. Dense, bordered, engineer-familiar; system font.

Primer look

Paste tokens.css (this folder) at the top of the page's <style>. Use only its --pa-* tokens. Colours are Primer's functional tokens from @primer/primitives (2026-10-12): the light and dark default themes, and the semantic foreground colours (accent, severe, success, done, sponsors) as the five categories, because Primer's data-vis emphasis colours fall under 3:1 on the dark canvas.

Type

• The system font stack for text and the system monospace stack for code. No web font.
• Scale (Primer markdown): h1 32/40 semibold, h2 24/30 semibold, h3 20/25 semibold, body 16/24, captions and labels 12/18. h1 and h2 get a 1px --pa-border bottom rule with padding-bottom: var(--pa-space-2), as on a GitHub README.
• Weights: 400 for body, 600 for headings and emphasis.

Layout

• Core's page grid (layout.css) with --pa-col 1012px (GitHub's container-lg) and --pa-col-wide 1120px. Prose runs the full column. The rail suits a sticky contents list, as on a GitHub README.
• Motion tokens are Primer's base easings (easeInOut, easeOut, easeIn) and functional durations (micro 100, short 200, medium 300, long 500ms), from @primer/primitives.
• Spacing only from --pa-space-* (4, 8, 16, 24, 32, 40, 48, 64).
• Sections are separated by space and the heading rule, not by boxes.

Surfaces

• --pa-bg for the page. A box (a table, a chart, a callout) gets a 1px --pa-border border, --pa-radius (6px) corners and a --pa-surface header row when it has a title. No shadows.
• Never a box inside a box.

Components

• "Show all": <summary> styled as Primer's invisible button: --pa-interactive text, no border, --pa-surface background on hover.
• Tables: the GitHub markdown table. 1px --pa-border on every cell, header cells semibold on --pa-surface, numbers right-aligned with tabular numerals.
• Key figure: the number at 32px semibold, a 12px label in --pa-text-2 below.
• Code blocks: --pa-surface background, --pa-radius corners, 16px padding, 13.6px monospace (85% of body, as GitHub sets it).
• A callout is Primer's markdown alert: a 4px left border in the state's colour (--pa-cat-1 note, --pa-cat-3 tip, --pa-cat-2 warning) with the state name in that colour as its first line. This is the one coloured border core allows, because the colour encodes the alert's state; give it data-encodes="alert state".

Charts

Recharts with --pa-cat-1…5, 2px rounded bar ends, axis text 12px --pa-text-2, and direct <LabelList> labels. Wrap each chart in the bordered box from Surfaces, with its title in the box header.

Diagrams

Paste core's mermaid.css after this look's tokens; it colours every diagram from --pa-* in both themes. For Primer's corners add pre.mermaid svg .node rect { rx: 6px; ry: 6px; }.

References

Check these before inventing a pattern the look doesn't cover:

• Primer
• Color and primitives
• Typography
• Layout
• Data visualization
• Accessibility