## Variable Management

You can manage global css variables with `Simple.$(varName,varValue,varValue2)` method. Here how it works:

```javascript
Simple.$('w') // return 50px
Simple.$('w','100px') // Changing --w to 100px
Simple.$('w','100px','50px') // if w=50px, change to 100px. If w=100px, change to 50px. Else - do nothing. 
```

Here is the example of usage:

```html
<script>
new Simple([
   {":root": {$d:'none'}},
   {".block": {d:'$d'}},
])
</script>

<button onclick="Simple.$('d','none','block')">Hide/show</button>
<div class="block">Hello</div>
```

> This method available only in browser's version