Reverse footnote rendering not correctly when having multipule reverse links

[SericaLaw]

Checklist

• I have read the tutorials and know the correct effect of the functional design.
• There are no similar reports on existing issues (including closed ones).
• I found the bug on the latest code of the master branch.

Describe the bug

If a footnote is referred to in more than one place in the article, the reverse footnote links will overlap with each other.

To Reproduce

Steps to reproduce the behavior:

Some sample markdown snippets:

content with reference1[^1]

other content with the same reference[^1]

reference again[^1]

reference again and again[^1]

References:

[^1]: footnote

Expected behavior

The reverse links should be separated from each other.

Screenshots

Desktop (Chrome)

Smartphone (Safari)

Software

• Ruby version: 2.7.0p0
• Gem version: 3.1.2
• Bundler version: 2.2.29
• Jekyll version: 4.2.1
• Theme version: 4.3.3

Desktop

• OS: Windows 10
• Browser: Chrome 93.0.4577.63

Smartphone

• OS: iOS 15.0.2
• Browser: Safari

Additional context