<div id="wrap">
  <div class="center">
    <div class="section">

      <div class="tabbed">
        
        <div class="tabbed__tabs">
          <div class="tab tab--active"><span>video #1</span></div>
          <div class="tab"><span>video #2</span></div>
          <div class="tab"><span>video #3</span></div>
        </div>
        
        <div class="tabbed__pages">
          <div class="page page--active">
            <iframe src="https://www.youtube.com/embed/lfWDnyxt4bo" frameborder="0" allowfullscreen></iframe>
          </div>
          <div class="page">
            <iframe src="https://www.youtube.com/embed/lfWDnyxt4bo" frameborder="0" allowfullscreen></iframe>
          </div>
          <div class="page">
            <iframe src="https://www.youtube.com/embed/lfWDnyxt4bo" frameborder="0" allowfullscreen></iframe>
          </div>
        </div>
        
      </div>

    </div>
  </div>
</div>

// autoprefixer: true

html,
body {
  margin: 0;
  padding: 0;
  font-family: sans-serif;
  font-size: 16px;
  line-height: 1.4;
  color: #555;
  background: #fff;
}

* {
  box-sizing: border-box;
}

#wrap {
  position: relative;
  padding-top: 60px;
  transition: padding-top .3s ease;
}

.section {
  padding: 40px;
}

.center {
  width: 100%;
  max-width: 1200px;
  margin: auto;
}

.tabbed {
  &__tabs {
    display: flex;
  }
  
  &__pages {
    position: relative;
    padding-top: 56.21%;
  }
}

.tab {
  padding: 10px 20px;
  background: #eee;
  cursor: pointer;
  user-select: none;
  
  &--active {
    background: #aef0cd;
    cursor: default;
  }
}

.page {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  visibility: hidden;
  
  iframe {
    width: 100%;
    height: 100%;
  }
  
  &--active {
    opacity: 1;
    visibility: visible;
    z-index: 1;
  }
}

$(function() {
  $('.tab').click(function() {
    var tabIndex = $(this).index();
    
    $('.tab').eq(tabIndex).addClass('tab--active').siblings().removeClass('tab--active');
    $('.page').eq(tabIndex).addClass('page--active').siblings().removeClass('page--active');
  });
});