Configure your site metadata, rendering configuration and such using YAML configuration. Create a
foo/ folder, and those settings apply only to that route. The YAML structure is the same as your Markdown frontmatter, and vice-versa. Settings in the YAML frontmatter apply onto that Markdown route only; whereas settings in an individual .yaml file apply to that entire sub-route tree. Emanote does a deep-merge of the parent YAML configurations, so you can have children override only what’s necessary. This is sometimes known as “data cascade”. The final merged YAML structure is passed to the HTML templates, of which you have full rendering control over.
Notice how this page’s sidebar colorscheme has changed to green? View the source of this page to see the magic involved. That CSS greenery you just saw too comes from YAML.