.box>li>ul{
 display: none;
}
.box>li:target>ul{
 display:block;
}

body {
    font-family: "Lucida Console", "Courier New", monospace;
    line-height: 1.2;
}

h1 {
  margin: 25px 10px;
}

h2 {
  margin: 25px 10px;
}
h3 {
  margin: 25px 22px;
}