Using CSS @import in an external stylesheet can add additional delays during the loading of a web page.
CSS @import allows stylesheets to import other stylesheets. When CSS @import is used from an external stylesheet, the browser is unable to download the stylesheets in parallel, which adds additional round-trip times to the overall page load. For instance, if first.css contains the following content:
@import url("second.css")
The browser must download, parse, and execute first.css before it is able to discover that it needs to download second.css. So to avoid that, use the <link> tag instead of CSS @import