Function setCssVar

setCssVar<E extends Element = HTMLElement>(
    name: `--${string}`,
    value: CssVarValue,
    target?: null | Target,
): E
Sets the CSS variable name to value in the optionally specified target.

If no target is specified, uses documentElement (i.e. :root).
Type Parameters
- E extends Element = HTMLElement
  Element representation of target.
Parameters
- name: `--${string}`
  Name of the CSS variable to set or update.
- value: CssVarValue
  Value of the CSS variable.
- Optionaltarget: null | Target = document.documentElement
  Optional Element, EventTarget, or CSS selector.
Returns E
Element representation of the specified target.
Throws
InvalidCssVarError if the name is not a valid CssVarName.

Throws
elements!InvalidElementError if the specified target wasn't found.
Example
HTML (Before)
```
<style>
  :root {
    --color-fg: green;
  }
</style>

<button id="example" style="--color-bg: blue;">
  Example
</button>
```
Set in Element
```
const element = findElement("#example")!;

setCssVar("--color-bg", "red", element);
```
Set in :root
```
setCssVar("--color-fg", "blue");
```
HTML (After)
```
<style>
  :root {
    --color-fg: blue;
  }
</style>

<button id="example" style="--color-bg: red;">
  Example
</button>
```
- Defined in src/css/setCssVars.ts:72