Example
<!DOCTYPE html>
<html>
<head>
<meta content="text/html;charset=utf-8" http-equiv="Content-Type">
<title>CSS test: all</title>
<style>
div { border: 1px solid black;
width: 300px;
margin-bottom: 5px;
}
div.warning { background-color: yellow;
color: red;
font-weight: bold;
}
div.ok { background-color: Chartreuse;
color: DarkGreen;
font-weight: bold;
}
div.normal { all: initial;}
</style>
</head>
<body>
<div >Some text</div>
<div class='warning'>Take care!</div>
<div class='ok' >All is good.</div>
<div class='normal' >Normal text</div>
<div >More text</div>
</body>
</html>