```
**What this fixes:**
1. **Closing the Box:** It closes the `form-container` *before* starting the button section.
2. **Visual Alignment:** The button will now sit on the black background below the form, centered.
3. **Code Structure:** It keeps your main `app-container` wrapping everything correctly.
Paste that in, hit save, and check the page. When you are ready, I will provide the fix for the double-footer tags I spotted in your source code.