Blueprinter

Blueprinter

Generate technical diagrams using HTML/CSS following the "Flat Engineering Blueprint" style guidelines.

Core Philosophy

Precise, Objective, High Data-Ink Ratio. The output should look like a technical specification sheet or an architectural diagram, NOT a marketing landing page.

Visual Rules

1. No Decorations

• NO drop shadows
• NO gradients
• NO glassmorphism/blur
• NO rounded buttons

2. Flat & Outlined

• Use 1px or 2px solid borders for structure
• Use white backgrounds for content blocks

3. Monochrome Base

| Element | Color | |---------|-------| | Background | Light Gray (#f8fafc) | | Canvas | White (#ffffff) with Slate Border (#cbd5e1) | | Text (Main) | High contrast Black (#0f172a) | | Text (Sub) | Slate Gray (#64748b) | | Accent | Use BLACK or ONE semantic color (e.g., Red for Error) sparingly |

4. Typography

• Headings/Labels: Sans-serif (Inter/Helvetica)
• Data/Paths/Code: Monospace (JetBrains Mono/Consolas)

5. Layout Structure

• The diagram must be contained within a diagram-canvas (a bordered box with padding)
• Header: Title + Uppercase Subtitle, separated by a solid bottom border
• Grid/Flexbox alignment: Everything must be strictly aligned

6. Elements

• Connectors: Thin, straight or orthogonal lines. Dashed lines for abstract relationships.
• Icons: Simple stroke SVG icons (no fill or complex details)
• Badges: Outlined or solid black/gray blocks. Small font size.

CSS Variable Reference

:root {
  --c-bg: #f8fafc;         /* Outer Background */
  --c-canvas: #ffffff;     /* Diagram Background */
  --c-border: #cbd5e1;     /* Slate-300 */
  --c-text-main: #0f172a;  /* Slate-900 */
  --c-text-sub: #64748b;   /* Slate-500 */
  --font-ui: 'Inter', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
}

HTML Structure Template

  
  
  [Diagram Title]
  
  
    :root {
      --c-bg: #f8fafc;
      --c-canvas: #ffffff;
      --c-border: #cbd5e1;
      --c-text-main: #0f172a;
      --c-text-sub: #64748b;
      --c-accent: #dc2626;  /* Optional: for errors/warnings only */
      --font-ui: 'Inter', sans-serif;
      --font-mono: 'JetBrains Mono', monospace;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-ui);
      background: var(--c-bg);
      padding: 40px;
      min-height: 100vh;
    }

    .diagram-container {
      max-width: 1200px;
      margin: 0 auto;
    }

    .diagram-canvas {
      background: var(--c-canvas);
      border: 1px solid var(--c-border);
      padding: 32px;
    }

    .diagram-header {
      border-bottom: 1px solid var(--c-border);
      padding-bottom: 16px;
      margin-bottom: 24px;
    }

    .diagram-title {
      font-size: 20px;
      font-weight: 600;
      color: var(--c-text-main);
      margin-bottom: 4px;
    }

    .diagram-subtitle {
      font-size: 11px;
      font-weight: 500;
      color: var(--c-text-sub);
      text-transform: uppercase;
      letter-spacing: 0.05em;
    }

    /* Component styles */
    .component {
      border: 1px solid var(--c-border);
      padding: 16px;
      background: var(--c-canvas);
    }

    .component-label {
      font-family: var(--font-mono);
      font-size: 12px;
      color: var(--c-text-sub);
      text-transform: uppercase;
      letter-spacing: 0.05em;
    }

    .component-value {
      font-family: var(--font-mono);
      font-size: 14px;
      color: var(--c-text-main);
      font-weight: 500;
    }

    /* Connector lines */
    .connector {
      stroke: var(--c-border);
      stroke-width: 1;
    }

    .connector-dashed {
      stroke: var(--c-border);
      stroke-width: 1;
      stroke-dasharray: 4 4;
    }

    /* Badges */
    .badge {
      display: inline-block;
      font-family: var(--font-mono);
      font-size: 10px;
      padding: 2px 6px;
      border: 1px solid var(--c-border);
      color: var(--c-text-sub);
    }

    .badge-solid {
      background: var(--c-text-main);
      color: var(--c-canvas);
      border-color: var(--c-text-main);
    }
  

  
    
      
        [Diagram Title]
        [Diagram Type / Version]
      
      
    
  

Usage Guidelines

1. Always use the CSS variables - never hardcode colors
2. Keep it flat - no shadows, no gradients, no blur effects
3. Use monospace for data - any technical values, paths, codes should use --font-mono
4. Align strictly - use CSS Grid or Flexbox with consistent gaps
5. Connect with lines - use SVG for connectors between components
6. Minimal icons - if icons are needed, use simple stroke-only SVGs

Example: Simple System Diagram

  
    System Architecture
    v1.0 / Overview
  
  
  
    
      Client
      Web App
    
    
      API
      REST Gateway
    
    
      Database
      PostgreSQL
    
  

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: yulonghe97
• Source: yulonghe97/ystack
• License: MIT

Install and usage instructions live in the source repository linked above.