Flexbox模型中的元素未完全对齐

Question

在所有链接下方的链接非常简单。有两个要素。一个在另一个内部。内部元素中心对齐（垂直）...应该是。但是不是，为什么？

https://jsfiddle.net/w2dL8feg/2/

.header {
  height: 67px;
  background-color: pink;
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: space-between;
}

.block {
  display: flex;
  flex-direction: column;
  font-family: "Standart", "PT Sans Narrow", sans-serif;
  font-size: 1.1rem;
  font-weight: 300;
  line-height: 1.1rem;
  text-align: center;
  background-color: green;
}

<div class="header">
  <div class="block">
    <div>text</div>
    <div class="phone-accent">8888888881</div>
  </div>
</div>