mdBook Auto Theme is a browser extension designed to automatically apply themes to websites generated by mdBook. This extension allows users to easily switch between different themes for both light and dark mode, making it convenient for those who frequently visit mdBook websites.

One of the standout features of mdBook Auto Theme is the ability to define selected themes globally. This means that users don't have to manually select the theme on every new page they load. However, it's important to note that changing the theme does require a page refresh.

To access the settings menu, users can simply click on the extension icon located in the top right corner of their browser. It's worth mentioning that the extension menu may need to be opened in order to find the icon.

Users can try out mdBook Auto Theme on the mdBook website itself, which is generated with mdBook. The extension supports a variety of themes, including "Light", "Rust", "Coal", "Navy", and "Ayu".