How to include css library correctly?

Question

css

There is a specific project structure, which has a directory containing sass fragments that are collected in one main.sass file. One of these fragments is the _libs.sass file in which css libraries are connected. They are connected using import, and since the file extension is .css, when compiling sass to css, there will be an extra http request.
Since it is correct to connect libraries; initially convert the library to a sass file or what?

Answer 1

.css remove