So In javascript you can do things like

```
document.querySelector('html').style.filter = 'invert(100%)'

```

Which Inverts colors on the entire webpage
but is there anyway to use

```
document.querySelector('html').style.pointer = 'something'

```

or a way to
add a css rule or something to the document?

example
you have an element like this

hello

then js gives an class
hello
then js adds a css rule?
.why {}