<!DOCTYPE html>
<meta charset="UTF-8">
<style>
.header {
  height: 81px;
  border-bottom: 1px solid #ddd;
}

.container-fluid {
  display: table;
  height: 100%;
}

.inner-nav, .extra-nav {
  display: table-cell;
  height: 100%;
}
</style>
<header class="header">
  <div class="container-fluid">
    <div class="inner-nav">
      <a id="invariant" href="#">Office Lunch</a>
    </div>
    <div class="extra-nav">
    </div>
  </div>
</header>
