Bootstrap CSS class .navbar-toggler

<nav class="navbar navbar-expand-lg navbar-light bg-light">
  <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarTogglerDemo02" aria-controls="navbarTogglerDemo02" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
  </button>
  <a class="navbar-brand" href="#">Navbar</a>

  <div class="collapse navbar-collapse" id="navbarTogglerDemo02">
    <ul class="navbar-nav mr-auto mt-2 mt-md-0">
      <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="#">Link</a>
      </li>
    </ul>
  </div>
</nav>

/* _navbar.scss:184 */
.navbar-toggler {
  display: none;
}

/* _navbar.scss:228 */
.navbar-toggler {
  color: $navbar-light-color;
  border-color: $navbar-light-toggler-border-color;
}

/* _navbar.scss:280 */
.navbar-toggler {
  color: $navbar-dark-color;
  border-color: $navbar-dark-toggler-border-color;
}