[BUG] TOC CSS style error in Chrome (invalid property value)

[gertvdijk]

Mandatory Step

• I am using latest production release of Elegant

Recommended Step

• I have attached link to my blog source code repository, so that developers can try to reproduce the issue at the end
• I can't my source code but I have linked my pelican configuration files to help developers reproduce the issue

Description

Describe the bug
Enable the TOC in an article. Then observe two things.

Two parts:

• In Google Chrome; a CSS style property value is shown as an error, and rendering as below in screenshot.
• In Firefox, the property value is accepted, but the rendering seems odd.

I am not sure what would be the intentional rendering, with or without list items. An ordered list with numbers seems odd in a <ul>, so I suspect something else was intended with this change in #509.

To Reproduce
See description.

Expected behavior
Firefox and Chrome to render the TOC identically.

Screenshots
Error in Chrome:

Rendering in Chrome (left) vs Firefox (right):

Desktop (please complete the following information):

• OS: Linux
• Browser Chrome Version 83.0.4103.61 (Official Build) (64-bit), Firefox 76.0.1 (64-bit).

Smartphone (please complete the following information):
not tested.

Additional context
Seems to be caused by #509 in commit 2d597ab.

[talha131]

Thank you. TOC needs overhaul. We haven't worked much on it since the first release.