Background in Toogle Navigation in the mobile version. The menu is not deconfigured but rather bottomless!

I have a template which in the mobile version is like the image below:

HowcanImakethemenustayontopofthelogo?Belowthecode:

<divclass="navbar-header">
   <button type="button" class="navbar-toggle" data-toggle="collapse" 
                 data-target=".navbar-collapse" style="z-index: 100000">
   <span class="sr-only">Toggle navigation</span>
   <span class="icon-bar"></span>
   <span class="icon-bar"></span>
   <span class="icon-bar"></span>
   </button>
   <a class="navbar-brand" href="index.html" style="z-index: 0">
      <img src="img/logo.png" alt="Basica" class="img-responsive logoMarca">
   </a>
</div>