
Duotone Map
A true gradient-map duotone that remaps shadows and highlights to two colors via an SVG filter.

A true gradient-map duotone that remaps shadows and highlights to two colors via an SVG filter.
Duotone Map is a true gradient-map duotone: an SVG filter desaturates the image to luminance, then remaps shadows to color A and highlights to color B (the Fire preset is a tritone). Switch --ifx-duo between the pre-baked filter ids (SVG filter attributes can't read CSS vars, so palettes are presets) and layer --ifx-contrast on top. IMPORTANT: the effect needs both the CSS and the accompanying inline <svg> <filter> block in the DOM — the copied HTML/React bundles it; a CSS-only integration must add the <svg> once. Fully static: identical on touch, nothing to reduce for prefers-reduced-motion.
Enhanced — SVG filter. This effect uses an enhanced feature — provide a graceful fallback for older browsers.