Documentation missing or how to to fine-tune CSS?

[FDelporte]

There is documentation available regarding styling on https://rapidocweb.com/css-parts.html

But how can elements within the exposed parts be changed?
For instance, in the following HTML, the inline definition display:flex on view-mode-request is causing too much white space and I would like to change it to display:block:

<div part="section-endpoint-body-expanded" class="endpoint-body get ">
    <div class="summary">
      ...
    </div>  

    <div class="req-resp-container"> 
      <div style="display:flex; flex-direction:column" class="view-mode-request row-layout">
          ...
        </div>  

        ...
      </div>
  </div>

None of these are working:

<style>
rapi-doc {
    --row-layout-display: block !important;
}
</style>

<style>
rapi-doc::part(section-endpoint-body-expanded) {
    --row-layout-display: block !important;
}
</style>

<rapi-doc
    theme="light"
    theme-custom-css="
        .view-mode-request.row-layout {
          display: block !important;
        }
      "
</rapi-doc>