Managed to move css injection to a link tag by moving the link tag inside the div.

Jellyfin.Plugin.MediaCleaner/Pages/home.js

@@ -1,5 +1,4 @@
 document.addEventListener('pageshow', async () => {
-    await fetchHomepageCSS();
     await updateMediaCleanerState();
 
     var moviesTitle = document.getElementById("moviesTitle");
@@ -136,16 +135,3 @@ const finishLoading = () => {
     console.log("Loading element: ", loadingElement);
     console.log("Homepage element: ", homepage);
 }
-
-const fetchHomepageCSS = async () => {
-    const response = await fetch('/web/configurationpage?name=home.css')
-
-    if(!response.ok){
-        throw new Error(`Response status: ${response.status}`);
-    }
-
-    const css = await response.text();
-    const styles = document.createElement('style');
-    styles.textContent = css;
-    document.head.appendChild(styles);
-}