Message if iframe.

main.py

@@ -936,6 +936,52 @@ def render_kta():
     return out_div
 
 
+iframe_overlay_style= """
+#iframe-overlay {
+    display: none;
+    position: fixed;
+    top: 0;
+    left: 0;
+    width: 100%;
+    height: 100%;
+    background-color: rgba(0, 0, 0, 0.8);
+    z-index: 9999;
+    font-family: Arial, sans-serif;
+}
+
+#iframe-overlay-content {
+    position: absolute;
+    top: 50%;
+    left: 50%;
+    transform: translate(-50%, -50%);
+    text-align: center;
+    background-color: rgba(255, 255, 255, 0.9);
+    padding: 20px;
+    border-radius: 10px;
+    box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
+}
+
+#iframe-overlay-content h2 {
+    color: #333;
+    margin-bottom: 10px;
+}
+
+#iframe-overlay-content p {
+    color: #555;
+    margin-bottom: 15px;
+}
+
+#iframe-overlay-content a {
+    color: #10A010;
+    text-decoration: none;
+    font-weight: bold;
+    font-size: 32px; 
+}
+
+#iframe-overlay-content a:hover {
+    text-decoration: underline;
+}"""
+
 iframe_js_detect = """
 function isInIframe() {
     try {
@@ -945,14 +991,25 @@ function isInIframe() {
     }
 }
 
-// Usage
+function showOverlay() {
+    const overlay = document.getElementById('iframe-overlay');
+    overlay.style.display = 'block';
+}
+
 if (isInIframe()) {
-    console.log("This page is in an iframe");
-} else {
-    console.log("This page is not in an iframe");
+    showOverlay();
 }
 """
 
+def html_get_iframe_overlay():
+    msgs = [
+        H2("Access the space directly to get full functionality:"),
+        H3("Click the link below:"),
+        A("ml-visoft-c-reviewer.hf.space", href="https://ml-visoft-c-reviewer.hf.space/"),
+    ]
+    divs = Div(Div(*msgs, id="iframe-overlay-content"), id="iframe-overlay")
+    return divs
+
 @rt("/")
 def index_get(session):
     if 'session_id' not in session:
@@ -973,7 +1030,10 @@ def index_get(session):
     title = Title('C code review for students')
     kta_social = render_kta()
     iframe_script = Script(iframe_js_detect)
+    iframe_css = Style(iframe_overlay_style)
     preamble = [
+        iframe_css,
+        html_get_iframe_overlay(),
         iframe_script,
         auth_area,
         H1("Evaluate your C code!"),