Scroll-down menu on click

<!--Navbar-->
<nav class="navbar navbar-inverse navbar-fixed-top">
    <div class="navbar-header">
      <a class="navbar-brand" href="#intro">Wake 'n Photo</a>
      <div class="show-menu">☰</div>
    </div>
    <div>
      <ul class="nav navbar-nav">
        <li><a href="#intro" class="page-scroll">Home</a></li>
        <li><a href="#gallery" class="page-scroll">Gallery</a></li>
        <li><a href="#contact" class="page-scroll">Contact</a></li>
      </ul>
    </div>
</nav>

@media screen and (max-width: 770px) {
    .navbar-nav {
        width: 100%;
        margin: 0px;
    }

    .navbar-fixed-top {
        background: #2C3E50;
    }

    .navbar-nav {
        display: none;
    }

    .navbar-nav > li {
        width: 100%;
        float: left;
        background: #2C3E50;
    }

    .show-menu {
        display: block;
    }
}