# Syntax Highlighting For syntax highlighting I use [Highlight.js](https://highlightjs.org) with a custom theme. Automatic language detection has been turned off, so you will probably want to specify the programming language you use like this
```rust
fn main() {
// Some code
}
```
## Improve default theme
If you think the default theme doesn't look quite right for a specific language, or could be improved.
Feel free to [submit a new issue](https://github.com/azerupi/mdBook/issues) explaining what you have in mind and I will take a look at it.
You could also create a pull-request with the proposed improvements.
Overall the theme should be light and sober, without to many flashy colors.
## Custom theme
Like the rest of the theme, the files used for syntax highlighting can be overwritten with your own.
- ***highlight.js*** normally you shouldn't have to overwrite this file. But if you need to, you can.
- ***highlight.css*** theme used by highlight.js for syntax highlighting.
If you want to use another theme for `highlight.js` download it from their website, or make it yourself,
rename it to `highlight.css` and put it in `src/theme` (or the equivalent if you changed your source folder)
Now your theme will be used instead of the default theme.