introduced modal loading spinner.

src/common/Loading.tsx

@@ -1,8 +1,18 @@
 import React from 'react';
 
-import './Loading.css';
+import DynamicPortal from './DynamicPortal';
+
+import styles from './Loading.module.css';
 
 const Loading: React.FC = () => {
-  return <div className="loading">Loading...</div>;
+  return (
+    <DynamicPortal>
+      <div className={styles.overlay}>
+        <div className={styles.spinnerContainer}>
+          <div className={styles.spinner}>Loading..</div>
+        </div>
+      </div>
+    </DynamicPortal>
+  );
 };
 export default Loading;