line-height being ignored when using flex display without text? http://stackoverflow.com/questions/34703306/why-is-line-height-being-ignored-when-using-flex-display-without-text

<!DOCTYPE html>
<html>
  <head>
  </head>
  <body>
    <h1 style="line-height: 200px; background: blue;  display: flex"><input value="expected large line-height - success." style="width: 250px"/>ALIK</h1>
    <h1 style="line-height: 200px; background: red;  display: flex"><input value="expected large line-height - FAILURE!!!" style="width: 250px"/></h1>
  </body>
</html>