Error rendering improvements (#1887)

src/Explorer/Controls/IndeterminateProgressBar.tsx

@@ -0,0 +1,37 @@
+import { ProgressBar, makeStyles } from "@fluentui/react-components";
+import React from "react";
+
+const useStyles = makeStyles({
+  indeterminateProgressBarRoot: {
+    "@media screen and (prefers-reduced-motion: reduce)": {
+      animationIterationCount: "infinite",
+      animationDuration: "3s",
+      animationName: {
+        "0%": {
+          opacity: ".2", // matches indeterminate bar width
+        },
+        "50%": {
+          opacity: "1",
+        },
+        "100%": {
+          opacity: ".2",
+        },
+      },
+    },
+  },
+  indeterminateProgressBarBar: {
+    "@media screen and (prefers-reduced-motion: reduce)": {
+      maxWidth: "100%",
+    },
+  },
+});
+
+export const IndeterminateProgressBar: React.FC = () => {
+  const styles = useStyles();
+  return (
+    <ProgressBar
+      bar={{ className: styles.indeterminateProgressBarBar }}
+      className={styles.indeterminateProgressBarRoot}
+    />
+  );
+};