Simple Elegant Modal Popup With JavaScript

A simple, elegant modal popup built with JavaScript and animated with CSS3 transitions & transforms.

How to use it:

Create the modal content following the html structure as these:

<div data-modal="trigger-demo" class="modal">
  <article class="content-wrapper">
    <button class="close"></button>
    <header class="modal-header">
      <h2>This is a modal</h2>
    </header>
    <div class="content">
      <p>More modal content here</p>
    </div>
    <footer class="modal-footer">
      <button>Okey</button>
      <button>Cancel</button>
    </footer>
  </article>
</div>

Create the trigger button to launch the modal. Note that the ‘data-modal-trigger’ attribute must match the value of the modal’s ‘data-modal’ attribute.

<button data-modal-trigger="trigger-demo" class="trigger">
  Launch
</button>

The primary CSS/CSS3 rules for the modal popup.

.modal {
  display: none;
  background-color: transparent;
  transition: all 0.25s ease;
}
.modal.open {
  position: fixed;
  top: 0;
  left: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100vh;
  background-color: rgba(0, 0, 0, 0.5);
}
.modal .content-wrapper {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  width: 50%;
  margin: 0;
  padding: 2.5rem;
  background-color: white;
  border-radius: 0.3125rem;
  box-shadow: 0 0 2.5rem rgba(0, 0, 0, 0.5);
}
.modal .content-wrapper .close {
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border: none;
  background-color: transparent;
  font-size: 1.5rem;
  transition: 0.25s linear;
}
.modal .content-wrapper .close:before, .modal .content-wrapper .close:after {
  position: absolute;
  content: '';
  width: 1.25rem;
  height: 0.125rem;
  background-color: black;
}
.modal .content-wrapper .close:before { transform: rotate(-45deg); }
.modal .content-wrapper .close:after { transform: rotate(45deg); }
.modal .content-wrapper .close:hover { transform: rotate(360deg); }
.modal .content-wrapper .close:hover:before, .modal .content-wrapper .close:hover:after { background-color: tomato; }
.modal .content-wrapper .modal-header {
  position: relative;
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  margin: 0;
  padding: 0 0 1.25rem;
}
.modal .content-wrapper .modal-header h2 {
  font-size: 1.5rem;
  font-weight: bold;
}
.modal .content-wrapper .content {
  position: relative;
  display: flex;
}
.modal .content-wrapper .content p {
  font-size: 0.875rem;
  line-height: 1.75;
}
.modal .content-wrapper .modal-footer {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  width: 100%;
  margin: 0;
  padding: 1.875rem 0 0;
}
.modal .content-wrapper .modal-footer > button {
  margin-left: 0.625rem;
  padding: 0.625rem 1.25rem;
  border: none;
  background-color: slategray;
  color: white;
  font-size: 0.87rem;
  font-weight: 300;
}
.modal .content-wrapper .modal-footer > button:first-child { background-color: #2ecc71; }
.modal .content-wrapper .modal-footer > button:last-child { background-color: #e74c3c; }

The main JavaScript to activate the modal window.

const buttons = document.querySelectorAll(`button[data-modal-trigger]`);
for(let button of buttons) {
  modalEvent(button);
}
function modalEvent(button) {
  button.addEventListener('click', () => {
    const trigger = button.getAttribute('data-modal-trigger');
    const modal = document.querySelector(`[data-modal=${trigger}]`);
    const contentWrapper = modal.querySelector('.content-wrapper');
    const close = modal.querySelector('.close');
    close.addEventListener('click', () => modal.classList.remove('open'));
    modal.addEventListener('click', () => modal.classList.remove('open'));
    contentWrapper.addEventListener('click', (e) => e.stopPropagation());
    modal.classList.toggle('open');
  });
}