@jupyter-lsp/jupyterlab-lsp/style/tooltip.css

Language Server Protocol integration for JupyterLab

.lsp-tooltip .jp-RenderedHTMLCommon {
  /* Reduce the default padding from 20px to 0px */
  padding-right: 0px;
}

.lsp-tooltip .jp-RenderedHTMLCommon > *:last-child {
  /* Reduce the default margin */
  margin-bottom: 0;
}