Hi I am trying to override some bootstrap 4 CSS/SCSS but my code does not work but when I run it in w3 school it works. am I missing something or am I just dumb? Also modifying the custom.scss file is not really an option as I want different CSS files to be served to the user depending on whether or not an option is enabled
<html>
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" integrity="sha384-MCw98/SFnGE8fJT3GXwEOngsV7Zt27NXFoaoApmYm81iuXoPkFOJwJ8ERdknLPMO" crossorigin="anonymous">
<style>
.active {
color: red;
}
</style>
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
<a class="navbar-brand" href="#">HTUDelta</a>
<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="navbar-nav mr-auto">
<li class="nav-item">
<a class="nav-link active" href="#">Home
<span class="sr-only">(current)</span>
</a>
</li>
<li class="nav-item active">
<a class="nav-link" href="#">Users only
<span class="sr-only">Users only</span>
</a>
</li>
<li class="nav-item active">
<a class="nav-link" href="#">Featchers
<span class="sr-only">Upcoming</span>
</a>
</li>
</ul>
<ul class="navbar-nav ml-auto">
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true"
aria-expanded="false">Dropdown </a>
<div class="dropdown-menu" aria-labelledby="colourBlindDropDown">
<a class="dropdown-item" href="?colour=Trichromacy&set=true">Trichromacy</a>
<a class="dropdown-item" href="?colour=Deuteranomaly&set=true">Deuteranomaly</a>
<a class="dropdown-item" href="?colour=Protanomaly&set=true">Protanomaly</a>
<a class="dropdown-item" href="?colour=Tritanomaly&set=true">Tritanomaly</a>
<a class="dropdown-item" href="?colour=Monochromaticy&set=true">Monochromaticy</a>
<div class="dropdown-divider"></div>
</div>
</li>
</ul>
<form class="form-inline my-2 my-lg-0">
<input class="form-control mr-sm-2" type="text" placeholder="Username" aria-label="Username">
<input class="form-control mr-sm-2" type="password" placeholder="Password" aria-label="password">
<button class="btn btn-outline-success my-2 my-sm-0" type="submit">Login</button>
</form>
</div>
</nav>
<!-- Optional JavaScript -->
<!-- jQuery first, then Popper.js, then Bootstrap JS -->
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<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>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js" integrity="sha384-ChfqqxuZUCnJSK3+MXmPNIyE6ZbWh2IMqE241rYiqJxyMiZ6OW/JmZQ5stwEULTy" crossorigin="anonymous"></script>
</body>
</html>The problem is that the selector isn't specific enough. Have a look at the following.
<html>
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" integrity="sha384-MCw98/SFnGE8fJT3GXwEOngsV7Zt27NXFoaoApmYm81iuXoPkFOJwJ8ERdknLPMO" crossorigin="anonymous">
<style>
.navbar-dark .navbar-nav .nav-link.active.active {
color: red;
}
</style>
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
<a class="navbar-brand" href="#">HTUDelta</a>
<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="navbar-nav mr-auto">
<li class="nav-item">
<a class="nav-link active" href="#">Home
<span class="sr-only">(current)</span>
</a>
</li>
<li class="nav-item active">
<a class="nav-link" href="#">Users only
<span class="sr-only">Users only</span>
</a>
</li>
<li class="nav-item active">
<a class="nav-link" href="#">Featchers
<span class="sr-only">Upcoming</span>
</a>
</li>
</ul>
<ul class="navbar-nav ml-auto">
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true"
aria-expanded="false">Dropdown </a>
<div class="dropdown-menu" aria-labelledby="colourBlindDropDown">
<a class="dropdown-item" href="?colour=Trichromacy&set=true">Trichromacy</a>
<a class="dropdown-item" href="?colour=Deuteranomaly&set=true">Deuteranomaly</a>
<a class="dropdown-item" href="?colour=Protanomaly&set=true">Protanomaly</a>
<a class="dropdown-item" href="?colour=Tritanomaly&set=true">Tritanomaly</a>
<a class="dropdown-item" href="?colour=Monochromaticy&set=true">Monochromaticy</a>
<div class="dropdown-divider"></div>
</div>
</li>
</ul>
<form class="form-inline my-2 my-lg-0">
<input class="form-control mr-sm-2" type="text" placeholder="Username" aria-label="Username">
<input class="form-control mr-sm-2" type="password" placeholder="Password" aria-label="password">
<button class="btn btn-outline-success my-2 my-sm-0" type="submit">Login</button>
</form>
</div>
</nav>
<!-- Optional JavaScript -->
<!-- jQuery first, then Popper.js, then Bootstrap JS -->
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<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>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js" integrity="sha384-ChfqqxuZUCnJSK3+MXmPNIyE6ZbWh2IMqE241rYiqJxyMiZ6OW/JmZQ5stwEULTy" crossorigin="anonymous"></script>
</body>
</html>Also note that you use the class active on different elements which doesn't work as expected. You use both li and a elements. Choose one element and adjust the selector according.
<li class="nav-item">
<a class="nav-link active" href="#">Home
<span class="sr-only">(current)</span>
</a>
</li>
<li class="nav-item active">
<a class="nav-link" href="#">Users only
<span class="sr-only">Users only</span>
</a>
</li>
A dirty way would by to overwrite style by using important. But it is not recommended. It also doesn't work since the 2 different elements
.active {
color: red !important;
}