This commit includes the following changes:
Gallery Page (gallery.html):
- Moved inline CSS to gallery.css for better organization and caching.
- Implemented a skeleton loader to improve perceived loading performance.
- Added a 'No results' message when search/filter yields no photos.
- Enhanced responsive image handling in the modal to load full-resolution images.
Admin Page (admin/index.html):
- Moved inline CSS to admin.css for better organization and caching.
- Fixed an aesthetic issue with the hover style on the 'Clear selection' button.
- Introduced a confirmation modal for bulk delete operations to prevent accidental data loss.
- Implemented a progress bar for file uploads, providing better user feedback.
