document.querySelectorAll('.bibTeX-section').forEach((section) => {
  const button = section.querySelector('.copy-button')
  if (!button) return

  const codeElement = section.querySelector('.bibTeX')
  const activeСontent = button.querySelector('.active-content')
  const inactiveСontent = button.querySelector('.inactive-content')

  const code = codeElement ? codeElement.innerText : ''

  button.addEventListener('click', () => {
    navigator.clipboard.writeText(code).catch((err) => {
      console.error('Ошибка копирования:', err)
    })

    button.classList.add('copy-button--inactive')
    button.classList.remove('copy-button--active')

    if (activeСontent) activeСontent.style.display = 'none'
    if (inactiveСontent) inactiveСontent.style.display = 'block'

    setTimeout(() => {
      button.classList.remove('copy-button--inactive')
      button.classList.add('copy-button--active')

      if (activeСontent) activeСontent.style.display = 'block'
      if (inactiveСontent) inactiveСontent.style.display = 'none'
    }, 3000)
  })
})