gecko-dev/devtools/client/jsonview/css/json-panel.css

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/******************************************************************************/
/* JSON Panel */

.jsonPrimitiveValue,
.jsonParseError {
  font-size: 12px;
  font-family: Lucida Grande, Tahoma, sans-serif;
  line-height: 15px;
  padding: 10px;
}

.jsonParseError {
  color: red;
}