<main>
  <button class="button" data-title="Good job!" data-msg="You clicked the button.">modal-window</button>
</main>

<div class="modal">
  <article class="modal__article">
    <h4 class="modal-title"></h4>
    <p class="modal-msg"></p>
  </article>
  
  <footer>
    <button class="button -full -close">close</button>
  </footer>
</div>

.modal {
	width: 24rem;
  color: #33465E;
  background-color: white;
	position: fixed;
	top: -50%;
	left: 50%;
	transform: translate(-50%, -50%);
  box-shadow: 0 0 1rem rgba(black, 0.1);
	opacity: 0;
	transition: opacity 550ms ease-in-out;
  
  &__article {
    text-align: center;
    padding: 2.5rem;
    
    .modal-title {
      font-size: 1.25rem;
      font-weight: 600;
      margin-bottom: 0.75rem;
    }
  }
  
  &__footer {
    width: 100%;
    height: 3rem;
  }
  
  &.in {
		opacity: 1;
		top: 50%;
	}
}

.button {
  font-weight: bold;
  color: #fff;
  padding: 15px 35px;
  border: 2px solid #fff;
  transition: all 250ms ease-in-out;
  
  &:hover {
    color: #fff;
    background-color: HSLA(0, 0%, 100%, .2);
  }
  
  &.-full {
    background-color: #33465E;
    width: 100%;
    height: 100%;
  }
}

main {
  width: 100vw;
  height: 100vh;
  color: #E0DEDE;
  background: linear-gradient(-90deg, #8DABD6, #95BFD6, #8DABD6);
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

var Modal = (function() {
  var modalOpen = function() {
    var title = $(this).data('title');
    var msg = $(this).data('msg');
    $('.modal-title').text(title);
    $('.modal-msg').text(msg);
    $('.modal').addClass('in');
  };
  
  var modalClose = function() {
    $('.modal').removeClass('in');
  };
  
  $('.button').click(modalOpen);
  $('.-close').click(modalClose);
})();