## setSpacingCssVars · function

Initializes `cssVars[0]` through `cssVars[12]` with an exponential spacing scale.

The scale is calculated as `2^(n-3) * base`, providing values from `0.25 * base` to `512 * base`.

**Signature:** `(base?: number, unit?: string) => void`

**Parameters:**

- `base: any` (optional) - - The base size for the spacing scale that will apply to `cssVars[3]`. Every step up the scale will double this, while every step down will halve it. Defaults to 1.
- `unit: any` (optional) - - The CSS unit to use, like 'rem', 'em', or 'px'. Defaults to 'rem'.

**Examples:**

```javascript
import A from 'aberdeen';
// Use default scale (0.25rem to 512rem)
A.setSpacingCssVars();

// Use custom base size
A.setSpacingCssVars(16, 'px'); // 4px to 8192px

// Use em units
A.setSpacingCssVars(1, 'em'); // 0.25em to 512em

// Show the last generated spacing values
A.onEach(A.cssVars, (value, key) => {
	A(`div #${key} → ${value}`)
}, (value, key) => parseInt(key)); // Numeric sort
```