/* Advertisement blocker for Twitter */
@namespace url(http://www.w3.org/1999/xhtml);
@-moz-document domain("twitter.com") {
  .promoted-tweet { display: none !important; }
}

/* Advertisement blocker for Twitter */
@namespace url(http://www.w3.org/1999/xhtml);
@-moz-document domain("twitter.com") {
  .promoted-tweet, .dismissible-container { display: none !important; }
}

Add an element to block
Add an element to block
