Add weekly popup

src/App.tsx

@@ -10,6 +10,7 @@ import logo from './assets/logo.png';
 import { ToastContainer } from 'react-toastify';
 import 'react-toastify/dist/ReactToastify.css';
 import { ResultOutput } from './components/ResultOutput';
+import { WeeklyPopup } from './components/WeeklyPopup';
 
 const App: React.FC = () => {
   const { url, handleUrlChange, handleFetch,
@@ -19,6 +20,7 @@ const App: React.FC = () => {
   return (
     <div className="App">
       {isLoading ? <Loader /> : null}
+      <WeeklyPopup />
       <div className='header'>
         <img src={logo} alt="Logo" className='logo' />
         <div className='searchBlock'>

src/components/WeeklyPopup/index.tsx

@@ -0,0 +1,55 @@
+import React, { useEffect, useState } from "react";
+import { Modal } from "../Modal";
+
+export const WeeklyPopup: React.FC = () => {
+    const [isPopupVisible, setIsPopupVisible] = useState(false);
+
+    useEffect(() => {
+        const now = new Date();
+        const lastPopupDate = localStorage.getItem("lastPopupDate");
+
+        if (lastPopupDate) {
+            const lastDate = new Date(lastPopupDate);
+            const oneWeekLater = new Date(lastDate);
+            oneWeekLater.setDate(lastDate.getDay() + 7);
+
+            if (now >= oneWeekLater) {
+                setIsPopupVisible(true);
+            }
+        } else {
+            setIsPopupVisible(true);
+        }
+    }, []);
+
+    const handleClosePopup = () => {
+        setIsPopupVisible(false);
+        localStorage.setItem("lastPopupDate", new Date().toISOString());
+    };
+
+    const ModalContent = () => {
+        return (<div style={{ maxWidth: '500px' }}>
+            <h1>Hello</h1>
+            <p>
+                This project is <b>open-source</b>, so you can <b>use it however you like</b>.
+            </p>
+            <p>
+                The <b>inspiration</b> for this project came from my <b>work tasks</b>, where I spent a lot of time retrieving data from FHIR implementation guides using FHIRPath expressions.
+            </p>
+            <p>
+                The project has been <b>developed</b> (or will be developed) entirely in my <b>free time</b>.
+            </p>
+            <p>
+                If you have any ideas, suggestions, or would like to contribute, please reach out via <a href="https://github.com/projkov/fhirpath-ui" target="_blank" rel="noreferrer">GitHub</a>.
+            </p>
+            <p>
+                You can find more information <b>about me</b> on this page: <a href="https://projkov.github.io" target="_blank" rel="noreferrer">projkov.github.io</a>
+            </p>
+            <p>
+                Best regards, <br />
+                Pavel Rozhkov
+            </p>
+        </div>)
+    }
+
+    return <Modal show={isPopupVisible} onClose={handleClosePopup} children={<ModalContent />} />
+};