p.error {
  color: red
}
p.message {
  color: green
}
table.devices, .devices td, .devices th {
  padding: .5em;
  border: 1px solid black;
  border-collapse: collapse;
}
td.invisible {
  background-color: red
}
td.visible {
  background-color: green
}
body {
  width: 100%;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}
table {
  width: 100%;
}
.active tr { position: relative; }
.active td, th {
    width: 75%;
}
.active td:first-child, th:first-child {
    width: 25%;
}
.bar {
  position: absolute;
  height: 100%;
  background-color: grey;
  right: 0;
}
