<!DOCTYPE html>
<html>
<head>
<title>Title of the document</title>
<style>
div {
background-color: #ff7c73;
padding: 10px;
}
div.first {
opacity: 0.1;
}
div.second {
opacity: 0.3;
}
div.third {
opacity: 0.6;
}
</style>
</head>
<body>
<div class="first">
<p>opacity 0.1</p>
</div>
<div class="second">
<p>opacity 0.3</p>
</div>
<div class="third">
<p>opacity 0.6</p>
</div>
<div>
<p>opacity 1 (default)</p>
</div>
</body>
</html>