Fenêtre modale

<script>
  function openModal(id) {
    let modal = document.getElementById(id);
    modal.classList.add('animate-modal');
    setTimeout(function(){ modal.classList.add('animated-modal'); modal.classList.remove('animate-modal'); }, 400);
  }
  
  function closeModal(id) {
    let modal = document.getElementById(id);
    modal.classList.add('animate-out-modal');
    modal.classList.remove('animated-modal');
    setTimeout(function(){  modal.classList.remove('animate-out-modal'); }, 400);
  }
</script>

<style>
  /* ===================================================================*/
  /* ============================= MODAL ============================ */
  /* ===================================================================*/

  .modal-mahii {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: rgba(31,32,38,.7);
    z-index: 99;
  }
  .modal-mahii-content {
      position: fixed;
      top: 10vh;
      left: 50%;
      transform: translateX(-50%);
      width: 600px;
      max-width: 95vw;
      background-color: #fff;
      padding: 30px 0 30px 30px;
  }
  .modal-mahii-content-inner {
      max-height: 70vh;
      overflow: auto;
  }
  .modal-mahii-header {
      padding-bottom: 12px;
  }
  .close-modal {
    position: absolute;
    top: 0px;
    right: 15px;
    cursor: pointer;
    font-size: 4rem;
    color: #000;
  }

  .animate-modal {
    display: block !important;
    opacity: 0;
    animation: fadeIn 0.4s ease-in-out 1 forwards;
  }

  .animated-modal {
    display: block !important;
    opacity: 1;
  }

  .animate-out-modal {
    display: block !important;
    animation: fadeIn 0.4s ease-in-out 1 reverse backwards;
  }

  @keyframes fadeIn {
    from {
      opacity: 0;
    }
    to {
      opacity: 1;
    }
  }

</style>