introduce .auth-shell and .auth-card classes for the centered,
narrow-card layout shared by login and register, then apply them
to the login template. form ids and the #login-error element are
preserved so the existing cypress auth flows still target them.
apply the page shell to the text detail page and add a scoped
.node-tree style block to app.css. the tree dom rendered by text.js
must keep ul/li with buttons and inputs as direct children of each
li (cypress relies on > selectors), so styling is applied entirely
via descendant selectors without wrapping the rendered nodes.
extend app.css with the every-layout style primitives (container,
stack, cluster, center) used to compose page shells, plus a small
component layer: site-header, btn (primary/secondary/danger), card
and card-link, list-cards, modal, error and a few utility classes.
no template changes here - templates start adopting these classes
in the per-page styling commits that follow.
introduce a single shared stylesheet under public/css. this first
section covers a minimal reset, warm/readable design tokens (color,
typography, spacing, radii, shadows), and base element styling for
headings, links, lists, forms, and buttons. layout primitives and
component classes follow in subsequent commits.
