Update styles.css

[Imran-imtiaz48]

Changes made to the CSS code for better readability, consistency, and logic improvement:

1. Formatting and Consistency: o Ensured consistent spacing and indentation throughout the code. o Combined multiple background properties into a single shorthand property where appropriate. o Used the shorthand margin and padding properties for conciseness.
2. Improved Selectors and Properties: o Simplified the background properties using shorthand notation. o Ensured consistent use of units (e.g., 0 instead of 0px). o Replaced redundant properties with more efficient ones (e.g., background shorthand instead of separate properties).
3. Structure and Comments: o Grouped related styles together under more logical sections. o Added comments to better organize and explain sections.
4. Responsive Design: o Moved the media query closer to the relevant section to improve logical grouping.
5. Removed Redundancies: o Eliminated unnecessary vendor prefixes and properties where modern browser support makes them redundant.