prometheus/web/static/css/alerts.css

.alert_header {
  cursor: pointer;
}

.alert_details {
  display: none;
}

.alert_rule {
  padding: 5px;
  color: #333;
  background-color: #ddd;
  font-family: monospace;
  font-weight: normal;
}

.alert_description {
  padding: 8px 0 8px 0;
}