# Theme ## Overview A theme is a collection of files (.twig, .css, .js, ...) that determine how the CMS website looks.\ The goal of a theme system is to let the end user change the look of the entire site all at once, on every page, while leaving the content intact. Even if the site has thousands of pages, you can change to a new theme quickly. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://harmonycms.gitbook.io/platform/marketplace/theme.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.