3x-ui/frontend/src/components/form/JsonEditor.css

.json-editor-host {
  border: 1px solid var(--ant-color-border);
  border-radius: 6px;
  overflow: hidden;
  background: var(--ant-color-bg-container);
}

.json-editor-host .cm-editor,
.json-editor-host .cm-editor.cm-focused {
  outline: none;
}

.json-editor-host:focus-within {
  border-color: var(--ant-color-primary);
  box-shadow: 0 0 0 2px color-mix(in srgb, var(--ant-color-primary) 10%, transparent);
}