fix: update instanceof check

windows-rdp/devolutions-patch.js

@@ -359,12 +359,11 @@ function setupAlwaysOnStyles() {
 
 function hideFormForInitialSubmission() {
   const styleId = "coder-patch--styles-initial-submission";
-  const existingContainer = document.querySelector("#" + styleId);
-  if (existingContainer) {
-    return;
-  }
 
-  const styleContainer = document.createElement("style");
+  /** @type {HTMLStyleElement | null} */
+  let styleContainer = document.querySelector("#" + styleId);
+  if (!styleContainer) {
+    styleContainer = document.createElement("style");
     styleContainer.id = styleId;
     styleContainer.innerHTML = `
       /*
@@ -373,8 +372,8 @@ function hideFormForInitialSubmission() {
       */
       :root {
         /*
-        Can be 0 or 1. Start off invisible to avoid risks of UI flickering, but
+          Can be 0 or 1. Start off invisible to avoid risks of UI flickering,
-        the rest of the function should be in charge of making the form
+          but the rest of the function should be in charge of making the form
           container visible again if something goes wrong during setup.
         */
         --coder-opacity-multiplier: 1;
@@ -387,13 +386,14 @@ function hideFormForInitialSubmission() {
     `;
 
     document.head.appendChild(styleContainer);
+  }
 
   // The root node being undefined should be physically impossible (if it's
   // undefined, the browser itself is busted), but we need to do a type check
   // here so that the rest of the function doesn't need to do type checks over
   // and over.
   const rootNode = document.querySelector(":root");
-  if (!(rootNode instanceof HTMLElement)) {
+  if (!(rootNode instanceof HTMLHtmlElement)) {
     styleContainer.innerHTML = "";
     return;
   }