JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/css/bootstrap.min.css">
<nav class="navbar navbar-light" style="background-color: #2C3E50 ;">
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="#navbarNav" aria-expanded="false" aria-label="Toggle navigation"> <span class="navbar-toggler-icon "></span> </button>
    <h1 class="navbar-brand mb-0 move-header ">NavBrand</h1>
    <div class="collapse width" id="navbarNav">
        <ul class="navbar-nav">
            <li class="nav-item active"> <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a> </li>
            <li class="nav-item"> <a class="nav-link" href="#">Features</a> </li>
            <li class="nav-item"> <a class="nav-link" href="#">Pricing</a> </li>
            <li class="nav-item"> <a class="nav-link disabled" href="#">Disabled</a> </li>
        </ul>
    </div>
</nav>

<script src="https://code.jquery.com/jquery-3.1.1.slim.min.js" integrity="sha384-A7FZj7v+d/sdmMqp/nOQwliLvUsJfDHW+k9Omg/a/EheAdgtzNs3hpfag6Ed950n" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/tether/1.4.0/js/tether.min.js" integrity="sha384-DztdAPBWPRXSA/3eYEEUWrWCy7G5KFbe8fFjk5JAIxUYHKkDx6Qin1DkWx51bBrb" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/js/bootstrap.min.js" integrity="sha384-vBWWzlZJ8ea9aCX4pEW3rVHjgjt7zpkNpZk+02D9phzyeVkE+jo0ieGizqPLForn" crossorigin="anonymous"></script>

CSS

.navbar {
    margin-top: 40px;
    display: inline-block;
    transition: all .5s ease-in-out;
}
    .navbar {
    border-bottom-right-radius: 200px;
    border-top-right-radius: 200px;
}

.navbar-nav {
  flex-flow: row nowrap;
  transition: all .5s ease-in-out;
}

.navbar {
    flex-flow: row nowrap;
    display: inline-flex;
    transition: all .5s ease-in-out;
}