<main>

    <div id="carousel">

       <div class="hideLeft">
        <img src="https://i1.sndcdn.com/artworks-000165384395-rhrjdn-t500x500.jpg">
      </div>

      <div class="prevLeftSecond">
        <img src="https://i1.sndcdn.com/artworks-000185743981-tuesoj-t500x500.jpg">
      </div>

      <div class="prev">
        <img src="https://i1.sndcdn.com/artworks-000158708482-k160g1-t500x500.jpg">
      </div>

      <div class="selected">
        <img src="https://i1.sndcdn.com/artworks-000062423439-lf7ll2-t500x500.jpg">
      </div>

      <div class="next">
        <img src="https://i1.sndcdn.com/artworks-000028787381-1vad7y-t500x500.jpg">
      </div>

      <div class="nextRightSecond">
        <img src="https://i1.sndcdn.com/artworks-000108468163-dp0b6y-t500x500.jpg">
      </div>

      <div class="hideRight">
        <img src="https://i1.sndcdn.com/artworks-000064920701-xrez5z-t500x500.jpg">
      </div>

    </div>

    <div class="buttons">
      <button id="prev">Prev</button>
      <button id="next">Next</button>
    </div>

  </main>

html, body, main
  width: 100%
  height: 100%
  margin: 0
  padding: 0

#carousel
  position: relative
  height: 400px
  top: 50%
  transform: translateY(-50%)
  overflow: hidden

  div
    position: absolute
    transition: transform 1s, left 1s, opacity 1s, z-index 0s
    opacity: 1

    img
      width: 400px
      transition: width 1s

    &.hideLeft
      left: 0%
      opacity: 0
      transform: translateY(50%) translateX(-50%)

      img
        width: 200px

    &.hideRight
      left: 100%
      opacity: 0
      transform: translateY(50%) translateX(-50%)
      img
        width: 200px

    &.prev
      z-index: 5
      left: 30%
      transform: translateY(50px) translateX(-50%)

      img
        width: 300px

    &.prevLeftSecond
      z-index: 4
      left: 15%
      transform: translateY(50%) translateX(-50%)
      opacity: .7

      img
        width: 200px

    &.selected
      z-index: 10
      left: 50%
      transform: translateY(0px) translateX(-50%)

    &.next
      z-index: 5
      left: 70%
      transform: translateY(50px) translateX(-50%)

      img
        width: 300px

    &.nextRightSecond
      z-index: 4
      left: 85%
      transform: translateY(50%) translateX(-50%)
      opacity: .7

      img
        width: 200px

.buttons
  position: fixed
  left: 50%
  transform: translateX(-50%)
  bottom: 10px

function moveToSelected(element) {

  if (element == "next") {
    var selected = $(".selected").next();
  } else if (element == "prev") {
    var selected = $(".selected").prev();
  } else {
    var selected = element;
  }

  var next = $(selected).next();
  var prev = $(selected).prev();
  var prevSecond = $(prev).prev();
  var nextSecond = $(next).next();

  $(selected).removeClass().addClass("selected");

  $(prev).removeClass().addClass("prev");
  $(next).removeClass().addClass("next");

  $(nextSecond).removeClass().addClass("nextRightSecond");
  $(prevSecond).removeClass().addClass("prevLeftSecond");

  $(nextSecond).nextAll().removeClass().addClass('hideRight');
  $(prevSecond).prevAll().removeClass().addClass('hideLeft');

}

// Eventos teclado
$(document).keydown(function(e) {
    switch(e.which) {
        case 37: // left
        moveToSelected('prev');
        break;

        case 39: // right
        moveToSelected('next');
        break;

        default: return;
    }
    e.preventDefault();
});

$('#carousel div').click(function() {
  moveToSelected($(this));
});

$('#prev').click(function() {
  moveToSelected('prev');
});

$('#next').click(function() {
  moveToSelected('next');
});