开发一个用于小程序的画布库

# Design Brief: Soft & Friendly

Warm low-saturation pastels, generous rounded corners, and approachable illustrations.

## Design Tokens

```css
:root {
  --background: #75cbea;
  --surface: #ffffff;
  --foreground: #1c2937;
  --muted-foreground: #537082;
  --accent: #168fc4;
  --radius: 4px;
  --font-heading: "Arial", ui-sans-serif, system-ui, sans-serif;
  --font-body: "Arial", ui-sans-serif, system-ui, sans-serif;
}
```

Color area ratio: Background #75CBEA (~69%) · Surface #FFFFFF (~27%) · Text #1C2937 (~2%) · Muted Text #537082 (~1%) · Accent #168FC4 (~1%). Background and surface dominate the canvas; reserve the accent color for primary buttons and active states.

## Layout & Conversion Structure

- Hero layout: Split Copy & Visual
- Navigation: Full-Width Top Bar
- Theme & density: Light · Balanced
- Border radius & elevation: Small Radius; no drop shadows—separate layers with hairline borders and whitespace
- Primary visual medium: Illustration / Character Art
- Conversion CTA: Download App / Install Extension
- Headline hook: Category Positioning Anchor
- Hero components: Custom Illustration, Large Hero Product Shot
- Spatial layout notes: Split Copy & Visual hero structure paired with download app / install extension CTA and no explicit trust bar.
- Visual summary: Soft & Friendly (Light canvas, balanced density) featuring split copy & visual layout and illustration / character art visuals.

## Avoid

- Harsh pure-black backgrounds
- Sharp 0px corners
- Cold technical jargon in hero copy

Implement the UI following the design tokens and layout specifications above: use only these color variables, and reserve the accent color strictly for primary actions and active states. Adopt only this visual style—never copy any reference product’s brand name, logo, copy, or imagery.