I have problem with vertically centering the element in the navigation bar on my page. This is my code:
body {
  margin:0;
}
header {
  background-color: #f2f2f2;
  height: 50px;
}
div {
  display: flex;
  justify-content: space-between;
  margin: auto 30px;
}<header>
  <div>
    <a href="#"><img class="header-logo" alt="logo"></a>
    <nav>
      <a href="#">Home</a>
      <a href="#">About</a>
      <a href="#">Services</a>
      <a href="#">Contact</a>
    </nav>
  </div>
</header>My question is why the div element is not centered in the header, since in the CSS code the top and bottom margins of the div element are set to auto, and that's what I do to center vertically.
 
     
     
    