As I am not a professional UI developer, I always learn and get confused about the CSS selector.
In this post, I just want to remember myself that for a HTML class, we can assign a number of class names. For example,
<!DOCTYPE html>
<html>
<head>
<style>
.header{
color: red;
}
.small-header{
font-size: 0.5em;
}
</style>
</head>
<body>
<div class="header small-header">
<h3>I am a header</h3>
</div>
<div class="header">
<h3>I am a normal header</h3>
</div>
</body>
</html>In this html, a class can have two class which is header and small-header.
If you run the page, it will look like:
