I am embedding gist's from github into my Ghost blog like so:

<script src="https://gist.github.com/matthiasguentert/27766a9d21ba6f88944a0c059d701a61.js" >
</script>

However, this gets badly styled by my Ghost theme.

The developer console reveals that my Ghost theme added extra styling to it.

So how can I remove e.g. <div class="lines"> ...? I've tried adding a short javascript, which however didn't work (very hacky, I know).

Funny enough, it works when executed on chrome console.

<script>
  const e = document.getElementsByClassName("lines");
  while(e.length > 0){e[0].parentNode.removeChild(e[0]);}
</script>