Enhance UI and Improve User Experience (#12)

* refactor(gui): improve layout and code formatting

- Enhance responsive grid layout for better mobile support
- Refactor image gallery and lightbox components
- Improve code readability with consistent formatting
- Remove unnecessary whitespace and blank lines

* feat(gui.py): conditionally render folder input and save button based on DOCKERIZED flag to improve compatibility with Docker environments

* feat(gui.py): add custom styles for a modern UI look and feel
style(gui.py): update UI components with new classes for consistency

* refactor(gui): update UI design and layout

Improve overall user interface with the following changes:
- Switch font to Roboto Mono
- Adjust card styles and shadows
- Reorganize input fields and layout
- Add dark mode toggle
- Enhance button styles and positioning
- Improve responsive design for various screen sizes

* refactor(gui): improve responsive layout

Enhance mobile and desktop UI for better user experience:
- Adjust grid and flex layouts for various screen sizes
- Modify element widths and spacing for improved responsiveness
- Relocate "Download Images" button to the top of output section
- Adjust font size and alignment of "Output" label
- Remove redundant "Download All" button