I want to use bootstrap only on the video. :       
      <div class="wrapper">
        <div class="overlay active">
          <div class="embed-responsive embed-responsive-16by9">
            <iframe class="embed-responsive-item" src="https://www.youtube.com/embed/DtNAqK_V-lg" frameborder="0" allowfullscreen></iframe>
          </div>
        </div>
      </div>
    </body>

</html>

I have a lot of other elements in my html file, and I don't want to tha bootstrap rules change them! I just want the bootstrap to the "wrapper" div and its inside. 
But when I paste the link of bootstrap on the <head> tag, it changes everything.

Is it possible?

Thank you for all help. :))