[Feature] Allow Custom CSS / Theme Styling & Plugin System for UI Customization

[nameIess]

I have searched the existing feature requests, both open and closed, to make sure this is not a duplicate request.

• Yes

The feature

Please consider adding support for custom user styling and/or an extensible plugin system to give users the freedom to customize the UI/UX.

Proposed Solutions:

• Custom CSS/Theme Settings: Allow users and server administrators to inject custom CSS or select/create custom themes (color accents, fonts, border radii, card styles) directly from the Web UI settings.
• Plugin / Extension Architecture: Introduce a modular plugin or theming hooks mechanism where community-created UI themes, layouts, or components can be loaded without modifying core code.
• Custom CSS Variables (Design Tokens): Expose primary theme tokens as accessible CSS variables so tweaking styling across the interface is simple and persistent across updates.

Use Case & Context:

Self-hosted users often prefer tailoring their photo gallery aesthetic to match their personal setup or other services. Giving users native support for custom CSS or theme plugins would provide complete styling freedom without requiring hard-coded forks or fragile reverse-proxy injection hacks.

Platform

• Server
• Web
• Mobile

[bo0tzz]

You can add custom CSS in the admin panel.