/*SCSS*/
.btn {
position : absolute;
&.active {
color: red;
}
}
/*CSS*/
.btn {position: absolute;}
.btn.active {color: red;}
$width: 555px;
div {
width: if($width > 300px, $width, null);
}
/*
(해석)
$width > 300px //조건
$width //true
null // false
*/