text: const login_container = document.querySelector('.login-container')
  const sign_in_btn = document.querySelector('#sign-in-btn')
  const sign_up_btn = document.querySelector('#sign-up-btn')
  
  // event when click sign up btn
  
  sign_up_btn.addEventListener('click', () => {
      login_container.classList.add('sign_up_mode');
  })
  // event when click sign in btn
  sign_in_btn.addEventListener('click', () => {
      login_container.classList.remove('sign_up_mode')
  })
  