使用引导程序访问此导航栏的正确方法是什么？

Question

我已经提供了一些现有代码的片段，希望可以给大家一些有关我采用的方法类型的想法。

header {
  height: 170px;
  text-align:center;
  border-top: 3px solid;
  border-image:   linear-gradient(to right, #e86125 33%, #90bb3f 33%, #90bb3f 66%, #ffcb0a 66%, #ffcb0a 99%) 5;
}
.header-logo {
  height: 75px;
}

<!-- Jquery -->
    <script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
    <!-- popper.min.js -->
    <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/umd/popper.min.js" integrity="sha384-ZMP7rVo3mIykV+2+9J3UJ46jBk0WLaUAdn689aCwoqbBJiSnjAK/l8WvCWPIPm49" crossorigin="anonymous"></script>
    <!-- Bootstrap -->
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" integrity="sha384-MCw98/SFnGE8fJT3GXwEOngsV7Zt27NXFoaoApmYm81iuXoPkFOJwJ8ERdknLPMO" crossorigin="anonymous">
    <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js" integrity="sha384-ChfqqxuZUCnJSK3+MXmPNIyE6ZbWh2IMqE241rYiqJxyMiZ6OW/JmZQ5stwEULTy" crossorigin="anonymous"></script>
<!-- Header/Navigation Bar -->
    <header>
      <nav class="navbar navbar-expand-sm navbar-dark bg-dark ">
        <a class="navbar-brand" href="index.html">
          Logo
        </a>
        <button class="navbar-toggler collapsed" type="button" data-toggle="collapse" data-target="#header-navigation" aria-controls="header-navigation" aria-expanded="false" aria-label="Toggle Navigation">
          <span class="navbar-toggler-icon"></span>
        </button>

        <div class="navbar-collapse collapse" id="header-navigation" style="">
          <ul class="navbar-nav ml-auto">
            <li class="nav-item active">
              <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
            </li>
            <li class="nav-item dropdown">
              <a class="nav-link dropdown-toggle" href="#" id="dropdown03" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Products</a>
              <div class="dropdown-menu" aria-labelledby="dropdown03">
                <a class="dropdown-item" href="#">1</a>
                <a class="dropdown-item" href="#">2</a>
                <a class="dropdown-item" href="#">3</a>
              </div>
            </li>
            <li class="nav-item">
              <a class="nav-link" href="#">About</a>
            </li>
            <li class="nav-item">
              <a class="nav-link" href="#">Contact</a>
            </li>
          </ul>
          <a href="#" class="">Customer Portal</a>

        </div>
      </nav>
    </header>

我坚持使用正确的方法来使用Bootstrap开发此标头。我尝试将导航栏上方的按钮分配给绝对属性，但这在移动设备上看起来不太好。任何帮助深表感谢。我提供了即时贴的屏幕截图。

documentation

我的代码：

<button class="navbar-toggler collapsed" type="button" data-toggle="collapse" data-target="#header-navigation" aria-controls="header-navigation" aria-expanded="false" aria-label="Toggle Navigation">
      <span class="navbar-toggler-icon"></span>
    </button>

    <div class="navbar-collapse collapse" id="header-navigation" style="">
      <ul class="navbar-nav ml-auto">
        <li class="nav-item active">
          <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
        </li>
        <li class="nav-item dropdown">
          <a class="nav-link dropdown-toggle" href="#" id="dropdown03" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Products</a>
          <div class="dropdown-menu" aria-labelledby="dropdown03">
            <a class="dropdown-item" href="#">1</a>
            <a class="dropdown-item" href="#">2</a>
            <a class="dropdown-item" href="#">3</a>
          </div>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">About</a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Contact</a>
        </li>
      </ul>
      <a href="#" class="">Customer Portal</a>