Custom CSS

When enabled, Obsidian will look for a file called obsidian.css in your vault root directory, and if it exists, applies it to the app itself.

The Obsidian Community has produced a great number of themes, and some of these are featured in the app. If Custom CSS is enabled, a Community Themes option will open in the Settings. Any of these themes can be used by clicking the Use button underneath. In the upper right of the Community Themes tab, there is a switch to determine whether to only see themes that are optimized for light or dark mode (whichever mode you are currently in). Turn this off to see all themes.

If you are building or modifying your own css, you can open the developer tools by using Ctrl/Cmd+Shift+I to get information on the elements you want to customize. Changes to obsidian.css will be detected automatically and reapplied. You do not need to restart the app. Be aware that applying a theme from Community Themes will overwrite your obsidian.css file, so if you have made changes be sure to move or rename your file if you want to keep them.