website/themes/hugo-theme-monochrome/exampleSite/content/en/layouts/balloon/_index.md

title, bookcase_cover_src, bookcase_cover_src_dark, type

title	bookcase_cover_src	bookcase_cover_src_dark	type
Balloon Layout	cover/balloon.png	cover/balloon_dark.png	bookcase

Balloon layout is useful for demonstrating information step-by-step.

This layout can be used on both section page (_index.md) and regular post (xxx.md).