<style>
.float-left {
float: left;
width: 100px;
height: 50px;
background-color: lightblue;
}
.float-right {
float: right;
width: 100px;
height: 50px;
background-color: lightpink;
}
.clear-both {
clear: both;
background-color: lightgray;
padding: 10px;
}
</style>
</head>
<body>
<div class="float-left">Float sinistra</div>
<div class="float-right">Float destra</div>
<div class="clear-both">Dopo clear: both</div>