Everything is in the folder you uploaded: the stylesheets, the JavaScript, a module per section and a template per page type. Nothing compiles, so the file you open is the file that runs.
Where the reasoning lives
The parts that are easy to break carry their explanation in the source. The partial that wires theme settings into CSS opens with why its selector is written the way it is, what happens with a different one, and which values are deliberately emitted only when they differ from the shipped default.
Extending it
A new section is a copy of a module folder with different fields and markup. It picks up the tokens by reading the same custom properties, so a module written a year later still matches the site without being told what the brand colours are.
What you inherit
Header, footer, blog post header, related articles and the icon renderer are partials rather than repeated blocks, and the header and footer are global, so an edit lands on every page at once.
Open the page, click the section, and its settings are on the right: headings, body copy, links, the icon on each item, how many columns, which colour scheme. Publishing the page is the whole workflow.
Making a new page
Create from a template and the arrangement comes with it. Sections can be dragged into a different order, duplicated, or removed, and none of that touches the template other pages are built from.
Changing the look
Colour, type and spacing sit in theme settings, away from page content. Picking a different preset repaints the site and leaves every word, field and section order exactly where it was.
What you cannot break from here
Editing a field changes that page. It does not edit a module, a template or another page, so there is no version of this where a copy change takes the site down.
