Update app.py

app.py

@@ -312,7 +312,10 @@ js_code = """
     captcha.async = true;
     captcha.defer = true;
     document.head.appendChild(captcha);
-    if (window.self !== window.top) document.getElementById('invariant-header').style.display = 'none';
+    if (window.self !== window.top) {
+        document.getElementById('invariant-header').style.display = 'none';
+        document.body.classList.add("invariant")
+    }
     const discord_webhook =  getStorage('discord_webhook')
     return [discord_webhook];
 })
@@ -325,10 +328,15 @@ css = """
 }
 footer {visibility: hidden}
 
-body.dark {
+body.invariant.dark {
     background-color: #111113;
     --body-background-fill: #111113;
 }
+
+body.invariant:not(.dark) {
+    background-color: white;
+    --body-background-fill: white;
+}
 """
 
 recaptcha_html = (