Nav dropdowns display error with Firefox

[azmeuk]

Describe the issue

Current Behavior

The nav dropdown example from the PicoCSS website display badly in Firefox

https://picocss.com/docs/nav#dropdowns

How Firefox displays it:

How Chromium displays it:

Expected Behavior

I would expect in Firefox the same display as in Chromium.

Reproduction URL

Just visit https://picocss.com/docs/nav#dropdowns

Environment

Example: ArchLinux + GNOME 49 Wayland + Firefox 143 and Chromium 140

[EpocDotFr]

Same here.

Firefox 143.0.3 (snap) on Ubuntu

[slavcodev]

This helps me (143.0.1)

nav details.dropdown {
  display: inline-block;
}