demo/quick-styling-inline-css.md is useful as a reminder that raw HTML and inline styles still work when you need a one-off visual proof. That page belongs as an example, not as the theming strategy itself, because the durable hooks live in the layout classes such as .vyasa-navbar-shell, .vyasa-main-shell, .vyasa-sidebar, and .vyasa-footer-card from vyasa/layout_page.py.