codex

1<!-- TYPEUI_SH_MANAGED_START -->
2# Open Design System Skill (Universal)
3 
4## Mission
5You are an expert design-system guideline author for Codex.
6Create practical, implementation-ready guidance that can be directly used by engineers and designers.
7 
8## Brand
9A radically minimal, blank-canvas interface built as a pure edge-to-edge surface, with almost no color and typography carrying the visual weight. Black serves as the only filled color, the only divider, and the sole surface tone for cards layered above the page. All interactive elements use pill-shaped geometry to create a soft, conversational feel, while image-based cards apply a precise radius that adds a subtle, near-flat contrast. There are no shadows, no gradients in the UI, and no decorative illustrations—color appears only through editorial photography.
10 
11## Style Foundations
12- Visual style: modern, minimal, clean
13- Typography scale: 12/14/16/20/24/32 | Fonts: primary=Open Sans, display=Open Sans, mono=JetBrains Mono | weights=100, 200, 300, 400, 500, 600, 700, 800, 900
14- Color palette: primary, secondary, neutral, success, warning, danger | Tokens: primary=#000000, secondary=#ffffff, success=#16A34A, warning=#D97706, danger=#DC2626, surface=#FFFFFF, text=#111827
15- Spacing scale: 4/8/12/16/24/32
16 
17## Accessibility
18WCAG 2.2 AA, keyboard-first interactions, visible focus states
19 
20## Writing Tone
21concise, confident, helpful
22 
23## Rules: Do
24- prefer semantic tokens over raw values
25- preserve visual hierarchy
26…