How to remove gap between bootstrap navbar and dropdown item

Question

I am struggling to find the source if this small transparent gap between my navbar and dropdown items. It is killing me. Can anyone lend a hand and help me locate and remove it?

My HTML

 <!-- Static navbar -->
<nav id="custom-bootstrap-menu" class="navbar navbar-default navbar-static-top">
  <div class="container">
    <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 id="navlogo">            
            <a class="navbar-brand" href="#">CHEEZ-IT!</a>
          </div>
        </div>
        <div id="navbar" class="navbar-collapse collapse">
          <ul class="nav navbar-nav">
            <li><a href="#">Home</a></li>
            <li class="dropdown">
              <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">About Us <span class="caret"></span></a>
              <ul class="dropdown-menu">
                <li><a href="#">Who are Cheez-it's</a></li>
                <li><a href="#">Credentials</a></li>
              </ul>
            </li>
            <li><a href="#contact">Our Services</a></li>
            <li class="dropdown">
              <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Industries <span class="caret"></span></a>
              <ul class="dropdown-menu">
                <li><a href="#">Cheeze-it Solar</a></li>
                <li><a href="#">Cheeze-it Infrastructure</a></li>
                <li><a href="#">Cheeze-it Harvest</a></li>                
              </ul>
            </li>

            <li><a href="#contact">Partners</a></li>
            <li><a href="#contact">Contact</a></li>
          </ul>
        </div><!--/.nav-collapse -->
      </div>
    </nav>

Here is my CSS, but I don't think any of this is causing it.

#custom-bootstrap-menu.navbar-default .navbar-brand {
    color: #fbb216;
}
#custom-bootstrap-menu.navbar-default {
    font-size: 14px;
    background-color: rgba(13, 65, 103, 1);
    border-width: 0px;
    border-radius: 0px;
}
#custom-bootstrap-menu.navbar-default .navbar-nav>li>a {
    color: rgba(255, 255, 255, 1);
    background-color: rgba(13, 65, 103, 1);
}
#custom-bootstrap-menu.navbar-default .navbar-nav>li>a:hover,
#custom-bootstrap-menu.navbar-default .navbar-nav>li>a:focus {
    color: rgba(13, 65, 103, 1);
    background-color: rgba(255, 255, 255, 1);
}
#custom-bootstrap-menu.navbar-default .navbar-nav>.active>a,
#custom-bootstrap-menu.navbar-default .navbar-nav>.active>a:hover,
#custom-bootstrap-menu.navbar-default .navbar-nav>.active>a:focus {
    color: rgba(13, 65, 103, 1);
    background-color: rgba(255, 255, 255, 1);
}
#custom-bootstrap-menu.navbar-default .navbar-toggle {
    border-color: #ffffff;
}
#custom-bootstrap-menu.navbar-default .navbar-toggle:hover,
#custom-bootstrap-menu.navbar-default .navbar-toggle:focus {
background-color: #ffffff;
}
#custom-bootstrap-menu.navbar-default .navbar-toggle .icon-bar {
background-color: #ffffff;
}
#custom-bootstrap-menu.navbar-default .navbar-toggle:hover .icon-bar,
#custom-bootstrap-menu.navbar-default .navbar-toggle:focus .icon-bar {
background-color: #ffffff;
}

Appreciate any help! Thanks

Answer 1

This rule (border-width: 0px;) is causing the gap.

You can add a bottom border that's the same color as your navbar (or you can reduce the margin of the dropdown-menu class by 1px but it does look awkward since the dropdown-menu is not perfectly inline with the dropdown trigger).

Alternative approach with margin

@media (min-width: 768px) {
    #custom-bootstrap-menu.navbar-default .dropdown-menu {
        border: none;
        margin-top: -1px;
    }
}

Bottom Border Approach: See Working Example

html {
  background-color: red;
}
#custom-bootstrap-menu.navbar-default .navbar-brand {
  color: #fbb216;
}
#custom-bootstrap-menu.navbar-default {
  font-size: 14px;
  background-color: rgba(13, 65, 103, 1);
  border: none;
  border-bottom: 1px solid rgba(13, 65, 103, 1);
  border-radius: 0px;
}
#custom-bootstrap-menu.navbar-default .navbar-nav > li > a {
  color: rgba(255, 255, 255, 1);
  background-color: rgba(13, 65, 103, 1);
}
#custom-bootstrap-menu.navbar-default .navbar-nav > li > a:hover,
#custom-bootstrap-menu.navbar-default .navbar-nav > li > a:focus {
  color: rgba(13, 65, 103, 1);
  background-color: rgba(255, 255, 255, 1);
}
#custom-bootstrap-menu.navbar-default .navbar-nav > .active > a,
#custom-bootstrap-menu.navbar-default .navbar-nav>.active>a:hover,
#custom-bootstrap-menu.navbar-default .navbar-nav>.active>a:focus {
  color: rgba(13, 65, 103, 1);
  background-color: rgba(255, 255, 255, 1);
}
#custom-bootstrap-menu.navbar-default .navbar-toggle {
  border-color: #ffffff;
}
#custom-bootstrap-menu.navbar-default .navbar-toggle:hover,
#custom-bootstrap-menu.navbar-default .navbar-toggle:focus {
  background-color: #ffffff;
}
#custom-bootstrap-menu.navbar-default .navbar-toggle .icon-bar {
  background-color: #ffffff;
}
#custom-bootstrap-menu.navbar-default .navbar-toggle:hover .icon-bar,
#custom-bootstrap-menu.navbar-default .navbar-toggle:focus .icon-bar {
  background-color: #ffffff;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.0.0/css/bootstrap.min.css" rel="stylesheet" />
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.0.0/js/bootstrap.min.js"></script>
<nav id="custom-bootstrap-menu" class="navbar navbar-default navbar-static-top">
  <div class="container">
    <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 id="navlogo"> <a class="navbar-brand" href="#">CHEEZ-IT!</a>

      </div>
    </div>
    <div id="navbar" class="navbar-collapse collapse">
      <ul class="nav navbar-nav">
        <li><a href="#">Home</a>

        </li>
        <li class="dropdown"> <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">About Us <span class="caret"></span></a>

          <ul class="dropdown-menu">
            <li><a href="#">Who are Cheez-it's</a>

            </li>
            <li><a href="#">Credentials</a>

            </li>
          </ul>
        </li>
        <li><a href="#contact">Our Services</a>

        </li>
        <li class="dropdown"> <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Industries <span class="caret"></span></a>

          <ul class="dropdown-menu">
            <li><a href="#">Cheeze-it Solar</a>

            </li>
            <li><a href="#">Cheeze-it Infrastructure</a>

            </li>
            <li><a href="#">Cheeze-it Harvest</a>

            </li>
          </ul>
        </li>
        <li><a href="#contact">Partners</a>

        </li>
        <li><a href="#contact">Contact</a>

        </li>
      </ul>
    </div>
    <!--/.nav-collapse -->
  </div>
</nav>