Flex items with same height in same row

Question

I have a div (.news-container) display flex. Inside that div, I have 5 items, the first one is 100% width, the other 4 are 50% width. The problem is those 4 items don't have the same height even they are flex item with align-content: stretch. Are they supposed to have same height when we set parent display flex or did i do something wrong here?

body {
  font-family: "Open Sans", Arial, sans-serif;
}

a {
  text-decoration: none;
}

h1,
h2,
h3,
h4,
h5 {
  margin: 0 0 20px 0;
}

.clearfix::after {
  content: "";
  clear: both;
  display: table;
}

.content {
  margin: 20px auto;
}

.float-content {
  float: left;
}

.left-content {
  width: 60%;
}

.right-content {
  width: 40%;
}

.news-container {
  display: flex;
  flex-wrap: wrap;
  padding-right: 5px;
  overflow: hidden;
  align-items: stretch;
  -webkit-align-content: stretch;
  -ms-flex-line-pack: stretch;
  align-content: stretch;
  -webkit-box-pack: justify;
  -webkit-justify-content: space-between;
  -ms-flex-pack: justify;
  justify-content: space-between;
}

.news-list-container {
  padding-left: 5px;
}

.news-container .item {
  position: relative;
  margin-bottom: 10px;
  width: calc(50% - 5px);
  padding: 0;
}

.news-container .item:nth-child(even) {
  margin-right: 10px;
}

.news-container .item:first-child {
  width: 100%;
  margin-right: 0;
}

.news-container .item .news-link {
  position: absolute;
  top: 0;
  left: 0;
  z-index: 2;
  background: #DC191B;
  color: #fff;
  padding: 10px;
  text-transform: uppercase;
}

.news-container .item img {
  width: 100%;
  display: block;
  margin-bottom: 0;
}

.news-container .item a.caption {
  display: block;
  padding: 10px 20px 13px 20px;
  background-color: #000;
  color: #fff;
  font-family: 'Roboto Condensed', sans-serif;
  font-size: 28px;
  font-weight: bold;
}

@media screen and (min-width: 1200px) {
  .content {
    max-width: 970px;
  }
}

<div class="wrapper">
  <div class="content clearfix">
    <div class="left-content float-content">
      <div class="news-container">
        <div class="item">
          <a class="news-link" href="#">
                        New
                    </a>
          <img src="https://www.w3schools.com/html/pic_trulli.jpg" />
          <a class="caption" href="#" target="_blank">
                        Lorem ipsum
                    </a>
        </div>
        <div class="item">
          <img src="https://www.w3schools.com/html/pic_trulli.jpg" />
          <a class="caption" href="#" target="_blank">
                        Lorem ipsum dolor sit amet
                    </a>
        </div>
        <div class="item">
          <img src="https://www.w3schools.com/html/pic_trulli.jpg" />
          <a class="caption" href="#" target="_blank">
                        Lorem ipsum dolor sit amet, consectetur adipiscing elit. Morbi a turpis sagittis, viverra nibh a, lobortis libero.
                    </a>
        </div>
        <div class="item">
          <img src="https://www.w3schools.com/html/pic_trulli.jpg" />
          <a class="caption" href="#" target="_blank">
                        Neque porro quisquam est qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit...
                    </a>
        </div>
        <div class="item">
          <img src="https://www.w3schools.com/html/pic_trulli.jpg" />
          <a class="caption" href="#" target="_blank">
                        Quisque sed tincidunt neque. Sed ut lacinia ex.
                    </a>
        </div>
      </div>
    </div>
    <div class="right-content float-content">
      <div class="news-list-container">
        <h2>
          Latest update
        </h2>
        <ul>
          <li>
            News Number 1
          </li>
          <li>
            News Number 2
          </li>
          <li>
            News Number 3
          </li>
          <li>
            News Number 4
          </li>
        </ul>
      </div>
    </div>
  </div>
</div>

Answer 1

Actually, your items are the same height. It's just the content in each item isn't expanding to cover the height of the item. Here's an example:

As shown with the dev tools outline, the item on the left (with shorter content) is the same height as the item on the right.

You can use display: flex on the items, so align-items: stretch gets applied to the content.

Add this to your code:

.news-container .item:nth-child(2),
.news-container .item:nth-child(4),
.news-container .item:nth-child(5) {
  display: flex;
  flex-wrap: wrap;
}

Now the content fills each item.

jsFiddle demo