function fixTweetMentions () {
  document.querySelectorAll('div.tweet-text> p').forEach((p) => {
    for (const node of p.childNodes) {
      if (node.nodeType === Node.ELEMENT_NODE && node.tagName === 'A' && node.classList.contains('mention')) {
        node.classList.add('initial-mention');
      } else if (node.nodeType === Node.TEXT_NODE && node.textContent.trim() === '') {
        // nothing to do
      } else {
        // we got to the main text of the tweet and must stop
        return;
      }
    }
  });
}
document.addEventListener('DOMContentLoaded', fixTweetMentions, false);