If we have changed something in CSS styles or JS scripts, then at most of users (who visited the site earlier) these changes can not be displayed or applyed. It occurs for the reason that the browser has the internal caching of styles and JS of scripts.
How to force to work changes in CSS and JS? It is necessary to add some GET parameter in the address of the css or js file.
For example, it is possible to add the version of the file ?v=1. Below the example is shown.
<link rel="stylesheet" href="/styles/styles.css?v=1" type="text/css" />