a:hover {
  background-color: white
}

div.zenh {
  background: #dff;
  color: #000
}
h2 {
  text-align: center
}
div.clear {
  clear: both
}
div.zenl {
  background: #dfd;
  color: #000;
  float: left
}
div.zenr {
  background: #dfd;
  color: #000;
  float: right
}
div.zenf {
  background: #fdd;
  color: #000;
}