jupyterlab/packages/property-inspector/style/base.css

/*-----------------------------------------------------------------------------
| Copyright (c) 2014-2019, Jupyter Development Team.
|
| Distributed under the terms of the Modified BSD License.
|----------------------------------------------------------------------------*/

.jp-PropertyInspector {
  display: flex;
  color: var(--jp-ui-font-color1);
  background: var(--jp-layout-color1);
}

.jp-PropertyInspector-content {
  flex-grow: 1;
}

.jp-PropertyInspector-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
}

.jp-PropertyInspector-placeholderContent {
  padding: 8px;
}