Removed styles for `.sidebar` and `.top-row` elements, including their background, layout, and responsive behavior, as they are no longer used. Simplified `main` and `article` elements by standardizing `margin` and `padding` to `0`.
Removed media query styles for `.top-row` and `.sidebar` to streamline responsive design. Updated global styles in `app.css` to ensure consistent spacing and alignment for `html`, `body`, `main`, and `.page`.
Focused on creating a cleaner, more minimal design by removing redundant styles and ensuring uniformity across the layout.
