Custom CSS and JavaScript

Before you start

• Selectors and scripts tested against the live website
• A rollback plan for website markup changes

Configure and verify

1. Write app-only CSS

   Add CSS up to the configured 5000-character limit. Use it for small app-specific adjustments, not a second complete website theme.

2. Write defensive JavaScript

   Add JavaScript up to 5000 characters. Check for elements before modifying them and avoid synchronous long-running work.

3. Save and rebuild

   The code is included in the generated settings and injected after page load inside the app.

4. Test navigation

   Visit multiple pages and SPA route changes, because elements and script state can differ after navigation.

5. Monitor website changes

   Recheck selectors after any website redesign. A stale selector can silently stop working.

CSS example

.desktop-only, footer { display: none !important; }

JavaScript example

window.addEventListener("load", function () {
  const headline = document.querySelector(".headline");
  if (headline) headline.textContent = "Welcome to the app";
});

Error containment

Android injects CSS into a dedicated style element and wraps custom JavaScript in try/catch so page script errors are logged without crashing the shell.

Test before release

• Public website is unchanged
• No critical controls are hidden
• Script handles missing elements
• SPA navigation was tested
• Performance remains acceptable