My toggle menu is hiding my slider in mobile device and enquire button popup is going back to slider?

My toggle menu is hiding my slider in mobile device and also click enquire now menu. The popup menu will come, but the slider is hiding the popup, and popup form is going back to slider, stuck with css properties to overcome this problem.

<div class="header">
<!--Top-Bar-->
<div class="top-bar">
<div class="container">
<div class="header-nav">
<div class="row">
<div class="col-md-3">
<h1><a class="navbar-brand" href="index.html">
<a href="http://lotusvaluedevelopers.com/"><img src="images/logoweb.png"  height="60"/></a></h1>
</div>
<div class="col-md-9">
<nav class="navbar navbar-default">
<!-- Brand and toggle get grouped for better mobile display -->
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
</div>
<!-- Collect the nav links, forms, and other content for toggling -->
<div class="collapse navbar-collapse nav-wil" id="bs-example-navbar-collapse-1">
<nav class="linkEffects linkHoverEffect_12">
<ul>
<li><a class="active" href="http://lotusvaluedevelopers.com"><span>Home</span></a></li> 
<li><a class="scroll" href="#about"><span>About Us</span></a></li> 
<li><a class="scroll" href="#service"><span>Services</span></a></li>
<li><a class="scroll" href="#layout"><span>Layout Plan</span></a></li>
<li><a class="scroll" href="#contact" id="popup" onclick="div_show()"><span>Enquire Now</span></a></li> 
</ul>
</nav>  
</div>
</nav>
</div>
</div>
</div>
</div>
</div>

css:

   @media(max-width:736px)
    {
    .navbar-toggle
    {
    display:inline-block;
    }
.navbar-collapse.in 
    {
        overflow-y: hidden;
    }
    }

Here is the link: http://lotusvaluedevelopers.com/HeritageParks/