diff --git a/src/main.tsx b/src/main.tsx
index 8ce3ce7..80698ca 100644
--- a/src/main.tsx
+++ b/src/main.tsx
@@ -55,6 +55,21 @@ import '@fontsource/barlow-condensed/700.css';
   }
 })();
 
+// Global error trap — shows error on screen in the APK so we can debug
+// without needing USB/adb. Remove once white screen is fixed.
+window.onerror = (msg, src, line, col, err) => {
+  const div = document.createElement('div');
+  div.style.cssText = 'position:fixed;top:0;left:0;right:0;bottom:0;background:#000;color:#ff0040;padding:16px;font:14px monospace;z-index:99999;overflow:auto;white-space:pre-wrap;word-break:break-all;';
+  div.textContent = `ERROR:\n${msg}\n\n${src}:${line}:${col}\n\n${err?.stack || ''}`;
+  document.body.appendChild(div);
+};
+window.onunhandledrejection = (e) => {
+  const div = document.createElement('div');
+  div.style.cssText = 'position:fixed;top:0;left:0;right:0;bottom:0;background:#000;color:#ff6600;padding:16px;font:14px monospace;z-index:99999;overflow:auto;white-space:pre-wrap;word-break:break-all;';
+  div.textContent = `UNHANDLED REJECTION:\n${e.reason?.stack || e.reason || 'unknown'}`;
+  document.body.appendChild(div);
+};
+
 createRoot(document.getElementById("root")!).render(
   <ErrorBoundary>
     <App />