npm install -g sass

Reference

sass --watch styles/style.scss styles/style.css

link rel="stylesheet" href="proxy.php?url=https%3A%2F%2FDevelopmentGuide.github.io%2F.%2Fstyles%2Fstyle.css"

$myColor: red;

#test {
color: $myColor;
}

nav {
ul {
margin: 0;
padding: 0;
list-style: none;
}
li {
display: inline-block;
}
p {
display: block;
padding: 6px 12px;
text-decoration: none;
}
}