-17 bytes

HatScripts · web-flow · commit cf34b247bdaf · 2019-11-03T14:25:05.000+11:00
Thanks to https://developer.mozilla.org/en-US/docs/Web/API/Document/head
diff --git a/applyCss.min.js b/applyCss.min.js
@@ -1 +1 @@
-function applyCss(c){var d=document,s=d.createElement('style');s.appendChild(d.createTextNode(c));(d.querySelector('head')||d.body||d.documentElement).appendChild(s)}
+function applyCss(c){let d=document,s=d.createElement('style');s.appendChild(d.createTextNode(c));(d.head||d.body||d.documentElement).appendChild(s)}

Original file line number	Diff line number	Diff line change
`@@ -1 +1 @@`
`1`		`-function applyCss(c){var d=document,s=d.createElement('style');s.appendChild(d.createTextNode(c));(d.querySelector('head')\|\|d.body\|\|d.documentElement).appendChild(s)}`
	`1`	`+function applyCss(c){let d=document,s=d.createElement('style');s.appendChild(d.createTextNode(c));(d.head\|\|d.body\|\|d.documentElement).appendChild(s)}`