"watchCSS" is being ignored in IE on first render

I am using "watchCSS" to init the slider based on the window width. It basically looks like this:

```
.flickity::after {
display: none;
content: "flickity";
}

@media (min-width: 576px) {
.flickity-sm-none::after {
content: "";
}
}
```

etc. So it enables it by default on extra small screens, then disables when I need it. Works like a charm, except in IE11 on first render. Even though it's supposed to be disabed on that screen resolution, it acts like a slider. When you refresh a page with F5 or resize it a little - it get back to normal. I know Codepen doesn't work in IE, but here is my snippet anyway: https://codepen.io/Deka87/pen/RwwyvQX.

Start with the watchCSS initialization path and reproduce the linked CodePen in IE11 at a responsive breakpoint. Compare the first render with a refresh or resize, then verify that the slider state matches the CSS breakpoint without requiring either workaround.

Written by the indexing model from the issue text.