I'm just starting out with bootstrap and I could really use some guidance on how to customize it. I managed to create a sample site, but I'm struggling to make modifications beyond the basic bootstrap settings. I have a "container" with blue font, but when I try to customize another container called "container new-place" with internal CSS, it doesn't seem to work. Is there a way for me to create my own custom bootstrap classes? Also, how can I change the text styles for ten instances of "container new-place" and five instances of "container" separately?
<!doctype html>
<html lang="en">
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" http-equiv="X-UA-Compatible" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" integrity="sha384-Vkoo8x4CGsO3+Hhxv8T/Q5PaXtkKtu6ug5TOeNV6gBiFeWPGFN9MuhOf23Q9Ifjh" crossorigin="anonymous">
<style>
h1 {
color: yellow;
}
.container{
color: blue;
}
.container.new-place {
color: red;
}
</style>
<title>Practice Title</title>
</head>
<body>
<div class="jumbotron jumbotron-fluid">
<div class="container">
<h1 class="display-3">Fluid jumbo heading</h1>
<p class="lead">Jumbo helper text</p>
<hr class="my-2">
<p>More info</p>
<p class="lead">
<a class="btn btn-primary btn-lg" href="Jumbo action link" role="button">Jumbo action name</a>
</p>
</div>
</div;
<div class="container new-place" date-time="00:00">
<h1>hello</h1>
</div>
<!-- Optional JavaScript -->
<!-- jQuery first, then Popper.js, then Bootstrap JS -->
<script src="https://code.jquery.com/jquery-3.4.1.slim.min.js" integrity="sha384-J6qa4849blE2+poT4WnyKhv5vZF5SrPo0iEjwBvKU7imGFAV0wwj1yYfoRSJoZ+n" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js" integrity="sha384-Q6E9RHvbIyZFJoft+2mJbHaEWldlvI9IOYy5n3zV9zzTtmI3UksdQRVvoxMfooAo" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js" integrity="sha384-wfSDF2E50Y2D1uUdj0O3uMBJnjuUD4Ih7YwaYd1iqfktj0Uod8GCExl3Og8ifwB6" crossorigin="anonymous"></script>
</body>
</html>