What is the meaning of the "@include" in .css Files?
<p>I don't understand , what is the meaning of the @include tag in .css files.
For Example :</p>

<pre><code>.wrapper {
display: flex;
width: 100%;
@include display(flex);
@include flex-direction(column);
@include align-items(center);
@include justify-content(center);
@include transition(all 2s linear);
}
</code></pre>