Phase 4 of the reader redesign (foliate-js ea268df):
- Webtoon mode for comics: continuous vertical scroll of all pages
(900px centered column on wide screens), lazy-loaded with a 150%
IntersectionObserver margin, far pages unloaded to bound memory
with stable aspect-ratio placeholders so the scrollbar never jumps.
Chosen per book (Paged | Webtoon segmented control in Settings →
Layout & Display; stored in localStorage per media item since a
webtoon title and a paged manga volume want different flows).
Toggling reloads the reader — the renderer is chosen at open time —
and progress restores from the saved page. Relocate events flow
through the same pipeline, so the slider, progress saving, back
stack, tap zones, and edge zones all work unchanged. Zoom/fit/
magnifier/spread controls hide in webtoon (natural-width scroll).
- Display filters for fixed-layout: brightness (30-130%) and
contrast (70-130%) sliders with live preview, plus Night Mode
(invert) — also a quick row in the ⋯ tools menu. One --fx-filter
CSS var drives everything: ::part(filter) on foliate-view iframes
(forwarded via the new exportparts attribute) and the webtoon
page images alike. Persisted as fx_brightness/fx_contrast/fx_invert
(types + defaults both sides); Restore Defaults resets them.