JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="//netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css">
<div id="navbar_top" class="navbar navbar-inverse" role="navigation">
    <div class="container">
      <div class="navbar-header">
        <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
          <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="#">Project name</a>
      </div>
      <form class="navbar-form navbar-right" role="form">
        <div class="form-group">
          <input type="text" placeholder="Login" class="form-control">
        </div>
        <div class="form-group">
          <input type="password" placeholder="Password" class="form-control">
        </div>
        <button type="submit" class="btn btn-success">Sign in</button>
      </form>
    </div>
  </div>
        
  <div id="solid_line"></div>
  <div id="toggle_auth">>>></div>

CSS

#navbar_top {
  border-radius: 0;
  margin-bottom: 0;
  /*display: none;*/
}
#solid_line {
  min-width: 100%;
  width: 100%;
  height: 5px;
  background: #222222;
}
#toggle_auth {
  position: relative;
  margin-left: 100px;
  width: 30px;
  height: 30px;
  background: #222222;
  color: #FFFFFF;
  transform: rotate(350dg);
}
#toggle_auth:hover {
  cursor: pointer;
}

JavaScript

$(document).ready(function() {
    $("#toggle_auth").click(function() {
        $("#navbar_top").slideToggle("slow");
    })
});