引导导航栏链接颜色不会更改

Question

我需要将导航栏链接更改为白色，并在导航栏上留出空间。我已经为此编写了代码，但我似乎不明白为什么/在哪里它一直被覆盖。导航栏的背景是一个图像，链接似乎变为白色，而图像不在其中，那么有没有办法修复这个问题并将图像保留在背景中？

有人能帮我理解我做错了什么吗？

.navbar {
  background-image: url("images/navbarbgnew.png");
  background-size: cover;
  margin: -30px 0 15px 0;
}

.navbar ul {
  display: flex;
  justify-content: space-around;
}

.navbar ul li a {
  color: #FFF;
  font-family: "Helvetica," sans-serif;
  font-weight: 600;
  font-size: 14px;
}

<nav class="navbar navbar-expand-md navbar-light bg-light mb-3">
  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation"><span class="navbar-toggler-icon"></span></button>
  <div class="collapse navbar-collapse" id="navbarSupportedContent">
    <ul class="nav navbar-nav">
      <li class="nav-item dropdown">
        <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
          BOOKS
        </a>
        <div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
          <a class="dropdown-item" href="#">Branding Sutra</a>
        </div>
      </li>
      <li class="nav-item dropdown">
        <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
          LEARNING LAB
        </a>
        <div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
          <a class="dropdown-item" href="#">Workshops</a>
          <a class="dropdown-item" href="#">Classes</a>
          <a class="dropdown-item" href="#">Audio Downloads</a>
        </div>
      </li>
      <li class="nav-item">
        <a class="nav-link" href="#">SERVICES</a>
      </li>
    </ul>
  </div>
</nav>

Answer 1

有人能帮我理解我做错了什么吗？

自定义css规则的特定性必须匹配或超过相应引导规则的特定性。

因此，在这种情况下，您需要一个如下所示的规则：

.navbar-light .navbar-nav .nav-link {
    color: red;
}

单击下面的“运行代码段”按钮，并展开到整个页面以验证其是否有效：

html lang-html prettyprint-override"><link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">

<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
    
<style>
.navbar-light .navbar-nav .nav-link {
    color: red;
}
</style>

<nav class="navbar navbar-expand-md navbar-light bg-light mb-3">
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation"><span class="navbar-toggler-icon"></span></button>
    <div class="collapse navbar-collapse" id="navbarSupportedContent">
        <ul class="nav navbar-nav">
            <li class="nav-item dropdown">
                <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                    BOOKS
                </a>
                <div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
                    <a class="dropdown-item" href="#">Branding Sutra</a>
                </div>
            </li>
            <li class="nav-item dropdown">
                <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                    LEARNING LAB
                </a>
                <div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
                    <a class="dropdown-item" href="#">Workshops</a>
                    <a class="dropdown-item" href="#">Classes</a>
                    <a class="dropdown-item" href="#">Audio Downloads</a>
                </div>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="#">SERVICES</a>
            </li>
        </ul>
    </div>
</nav>