title: How to extend/modify (customize) Bootstrap with SASS
body: <p>I want to create a website theme based on Bootstrap. I want to extend Bootstrap's default components and change some of them. For this, I would need <em>access</em> to SASS variables that Bootstrap defines so I can override them.</p>
  
  <p>I though of cloning Bootstrap from GitHub and changing it directly, but I heard that's actually not good practice. Could you give me some advice please?</p>