One line code blocks poorly render on Firefox

While trying to view a code block from Firefox, if the block only contains one line of code it is rendered closer to the line number.

I tried on the quickstart example this markdown file:

---
title: "My First Post"
date: 2022-01-12T15:47:42+01:00
draft: true
---

## Code block with one line

(this should be a codeblock)
a = [b**2 for b in range(5)]


## Code block with multiple lines

(this should be a codeblock)
a = [b**2 for b in range(5)]
print(a)

with the following config.toml file:

baseURL = "http://example.org/"
languageCode = "en-us"
title = "My New Hugo Site"
theme = "ananke"

[markup]
  [markup.highlight]
  pygmentsUseClasses = true
    anchorLineNos = false
    codeFences = true
    guessSyntax = false
    hl_Lines = ""
    lineAnchors = ""
    lineNoStart = 1
    lineNos = true
    lineNumbersInTable = true

On Chrome and Microsoft Edge everything looks good.

Since this was tried on an empty project I feel like it is more a bug. I noticed that the bug can be fixed if the generated html is free of any white spaces inside the span tags.