script.js

document.addEventListener('click', function (event) {
  let tagItem = event.target.closest('.m5dd_list')
  let resultArea = event.target.closest('#m5dd_result')
  if (tagItem) {
    if (tagItem.classList.contains('use')) {
      tagItem.classList.remove('use')
    } else {
      tagItem.classList.add('use')
    }
    document.getElementById('m5dd_result').innerText =
      Array.from(document.querySelectorAll('.m5dd_list.use>span:nth-child(1)'))
        .map(v => v.innerText)
        .join(', ')
  } else if (resultArea) {
    const selection = window.getSelection()
    selection.removeAllRanges()
    const range = document.createRange()
    range.selectNodeContents(resultArea)
    selection.addRange(range)
  } else {
    return
  }
})