a {text-decoration: none}
a:target {background-color: yellow}
pre {line-height: 1.4em}
.ext {font-style: italic}
.def {border: 1px solid grey}
.ref {border: 1px dashed grey}
.def, .ref {font-weight: bold}
.id {display: none}
body.id .id {display: inline}