> For the complete documentation index, see [llms.txt](https://mpithemes.gitbook.io/shella-shopify-theme/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mpithemes.gitbook.io/shella-shopify-theme/theme-settings/developer.md).

# Developer

### Our recommendations: 

1\) track all the custom changes that you apply to the theme. It will help you greatly in future theme updates.

We recommend using the **GIT software** to track theme file changes.

&#x20;Git - [<mark style="color:blue;">https://en.wikipedia.org/wiki/Git</mark>](https://en.wikipedia.org/wiki/Git)

2\) keep your changes as separate as you can. The next two options are a good example of how to keep CSS and JS code separate.

### Enable custom CSS file&#x20;

&#x20;Add your custom CSS style to custom.css. Edit the file using the online theme editor at Theme actions -> Edit code.

### Enable custom JavaScript file&#x20;

&#x20;Add your custom JavaScript code to custom.js. Edit the file using the online theme editor at Theme actions -> Edit code.