I will optimize the layout for `ContactSection.js` and fix the responsive issues, including the "bottom text" visibility and mobile layout.

### Plan:
1.  **Modify `src/App.css` to fix layout and scrolling issues:**
    *   **Enable Scrolling:** Update the `.section` class to include `overflow-y: auto` and `overflow-x: hidden`. This is critical for mobile devices where content height often exceeds the viewport, ensuring the bottom text (footer) in `ContactSection` is accessible.
    *   **Optimize Mobile Layout for ContactSection:**
        *   Adjust `.contact-section` margins and paddings for mobile screens (`max-width: 768px`) to reduce wasted space and ensure content fits better.
        *   Tweaking `.contact-footer` spacing.
    *   **Verify/Fix HeroSection Video Layout:**
        *   Ensure the container for the video (`.hero-right`) has appropriate sizing on mobile so the video (`stay.mp4`) displays correctly within its container, addressing the user's concern about the "responsive layout" of that element.

2.  **Verify the changes:**
    *   I will verify the CSS changes by checking the code structure and ensuring the styles logically solve the overflow and spacing issues.