Hello
I tested code from this book with DW 8 and it seems not working for me for example

ul#nav {
font-family: Verdana, Geneva, Helvetica, sans-serif;
font-size: .82em;
background-color: #DDD;
}
ul#nav li a {
border: 1px solid #000;
display: block;
float: left;
padding: 3px;
}