at/static/css/basic.css

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
}