• 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 master branch.

Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

• Ruby version: [by running: ruby -v]
• Gem version: [by running: gem -v]
• Bundler version: [by running: bundle -v]
• Jekyll version: [by running: bundle list | grep " jekyll "]

• OS: [e.g. macOS 10.15.6]
• Browser: [e.g. Chrome 85.0.4183.83 (Official Build) (64-bit)]

• Device: [e.g. iPhone 6]
• OS: [e.g. iOS 13.6.1]
• Browser: [e.g. Chrome 22]