Bootstrap Navbar collapse point < 768px

Question

This is an OLD question for Bootstrap 3 -> changing the collapse point for the navbar, but the methodologies suggested here:

https://coderwall.com/p/wpjw4w/change-the-bootstrap-navbar-breakpoint

and here:

Bootstrap 3 Navbar Collapse

do not work for collapsing below 768px, it only seems to work for extending the collapse point, not retracting it. I have a particular situation where my navbar has 3 buttons, so it doesn't need to collapse so early. I would like it to collapse at 420px instead.

Is there a CSS solution to this? If not, can somebody point me towards the correct attribute in the bootstrap customisation page which I need to change and download? Is it the generic breakpoints perhaps? Because there is nothing I can see which says Navbar breakpoints:

http://getbootstrap.com/customize/

As requested, my HTML for the navbar is simply:

<nav class="navbar navbar-default navbar-fixed-top">
    <div class="container-fluid">
        <div class="navbar-header">
            <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar" aria-expanded="false" aria-controls="navbar">
                <span class="sr-only">Toggle navigation</span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
            </button>
        </div>

        <div class="navbar-collapse collapse" id = "navbar">
            <ul class="nav navbar-nav navbar-left">
                <li class = "navbar_buttons"><a id = "new_route_button"><strong>New Route</strong></a></li>
                <li class="divider-vertical"></li>
                <li class = "navbar_buttons"><a id = "clear_route_button">Clear Route</a></li>
            </ul>
            <ul class="nav navbar-nav navbar-right">    <!--Right justified navbar list-->
                <li class = "navbar_buttons"><a id = "about_button">About</a></li>
            </ul>
        </div>

    </div>  <!-- Container -->

</nav>  <!-- End of Navbar Container -->

Then I have some CSS to add a vertical division:

/*Preventing vertical dividers from appearing collapsed*/
@media (max-width: 420px) {
.navbar-collapse .nav > .divider-vertical {
    display: none;
  }
}

/*Defining the vertical dividers*/
.navbar .divider-vertical {
  height: 50px;
  margin: 0 9px;
  border-right: 1px solid #ffffff;
  border-left: 1px solid #DADADA;
}

.navbar-inverse .divider-vertical {
  border-right-color: #222222;
  border-left-color: #111111;
}

Answer 1

Yes, changing the breakpoint to anything less than 768px is different than changing the breakpoint over 768px. You need to override all of the Bootstrap defaults that normally make it collapse.

@media only screen and (min-width: 420px) {
    .collapse {
        display: block;
    }

    .navbar-header {
        float: left;
    }

    .navbar-toggle {
        display: none;
    }

    .navbar-nav.navbar-left {
       float: left;
       margin: 0;
    }

    .navbar-nav.navbar-right {
       float: right;
       margin: 0;
    }
    .navbar-nav>li {
        float: left;
    }
    .navbar-nav>li>a {
        padding-top: 15px;
        padding-bottom: 15px;
    }
}

@media only screen and (max-width: 420px) {
     .collapse {
        display: none;
     }

     .navbar-header {
        display: block;
     }
}

http://www.bootply.com/wpUuFIZqJ2