使用纯Javascript突出显示包含其他元素的元素的textContent或innerText，该元素也基于用户的searchedWords

function highlightKeywords(searchedWords, parentElement) {
  const elements = parentElement.getElementsByTagName('*');
  
  for (let i = 0; i < elements.length; i++) {
    const element = elements[i];
    const text = element.textContent || element.innerText;
    
    if (text.includes(searchedWords)) {
      const highlightedText = text.replace(new RegExp(searchedWords, 'gi'), '<span class="highlighted">$&</span>');
      element.innerHTML = highlightedText;
    }
  }
}

// 调用示例
const parentElement = document.getElementById('parentElement');
const searchedWords = '关键词';
highlightKeywords(searchedWords, parentElement);