<nav class="navbar navbar-expand-md navbar-light">
  <button class="navbar-toggler mr-auto mb-2 bg-light" data-toggle="collapse" data-target="#myNavbar">
    <span class="navbar-toggler-icon"></span>
  </button>
  <div class="collapse navbar-collapse" id="myNavbar">
    <div class="container-fluid border border-success">
      <div class="row border border-danger">
        <!-- sidebar -->
        <div class="col-lg-3 bg-info">
			123
        </div>
        <!-- end of sidebar -->

        <!-- top-nav -->
        <div class="col-lg-9 bg-warning">
			456
        </div>
		this row must be full width but it isn't.
        <!-- end of top-nav -->
      </div>
    </div>
  </div>
</nav>