Same as https://github.com/go-gitea/gitea/pull/29822 but for light theme. Slight shift towards blue and made the themes match more, like on header and footer background. Before <img width="1342" alt="Screenshot 2024-03-16 at 00 43 03" src="https://github.com/go-gitea/gitea/assets/115237/b46021a1-241c-446a-b220-ca25cc90f3bf"> After <img width="1343" alt="Screenshot 2024-03-16 at 00 45 21" src="https://github.com/go-gitea/gitea/assets/115237/1c898875-a6bb-4bd3-b059-f82e1a145c99"> Before <img width="1018" alt="Screenshot 2024-03-16 at 00 43 13" src="https://github.com/go-gitea/gitea/assets/115237/d237ee7d-b4cc-4688-a074-1e96515ac475"> After <img width="1022" alt="Screenshot 2024-03-16 at 00 43 50" src="https://github.com/go-gitea/gitea/assets/115237/89b1da77-6bc9-4b38-9688-546e794aadfa"> (cherry picked from commit 68169133a3b0d29fe348ee065088d33f6dd1b087)
