.theme input {
  display: none;
}

.theme {
  margin: 0 0.3em 0 0;
}

.theme input + label {
  color: #f90;
  cursor: pointer;
  border-bottom: 3px solid transparent;
  padding-bottom: 0.1em;
  margin-left:0.6em;
}

.theme input:hover + label,
.theme input:checked + label {
  border-bottom: 3px solid #eee;
  color: #eee;
}