PROMPT USED
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Build a standalone, fully offline HTML5 page: a cathedral stained-glass window
with sun rays and colored glow. Palette: rich ruby, sapphire, emerald, gold lead
lines. Signature: SVG geometric panels, animated light rays, soft colored glow
pulsing. Hard constraints: one self-contained .html, all CSS in one <style>, all
JS in one <script>, zero external dependencies (system fonts only, no CDN, no
external images/SVG files), responsive 320px→4K, valid HTML5, must run by
double-click with no network requests. WOW bar: Awwwards/SiteInspire-caliber,
distinctive art direction, real motion, one signature effect. A matching .txt
with the same base name must accompany it.


TITLE
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Lumen Vitæ — a luminous rose window that breathes daylight through leaded glass.


DESIGN DESCRIPTION
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A dark cathedral interior opens onto a single, enormous rose window set inside a
pointed gothic-arch stone frame. The window is drawn as real inline SVG: five
concentric rings of annular-sector "glass" panels — each filled with a backlit
radial gradient — are separated by glowing gold lead came (concentric circles,
radial mullions and tracery bosses), all softened by a subtle SVG glow filter. At
the hub sits a radiant medallion with an eight-point core star. Behind the whole
window a large screen-blended, blurred multicolor halo (ruby, sapphire, emerald,
amethyst) pulses slowly as if clouds of light are passing over the glass, while a
slowly rotating conic-gradient cone casts animated colored light rays across the
nave. Below, a trapezoidal projected "light pool" pools on the stone floor and a
field of drifting dust motes twinkles brightest inside the beam. The entire glass
layer gently tilts and rotates toward the pointer for a living, dimensional feel,
and a soft highlight sweeps diagonally across the lead lines like passing sun.


MAJOR VISUAL TECHNIQUES
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- Procedurally generated SVG rose window: annular-sector (donut-segment) paths
  computed in JS for perfect radial symmetry across five color-cycled rings.
- Backlit glass look via per-color radial gradients (bright core → deep edge) and
  a gold linear "lead" gradient for the came, with an SVG feGaussianBlur glow
  filter on every lead line and boundary.
- A pulsing, screen-blended, blurred multicolor halo behind the window for the
  "soft colored glow" that breathes in and out on a 7s ease loop.
- A slowly rotating conic-gradient light-ray cone (mix-blend-mode: screen) plus a
  blurred central bloom, and a matching animated light pool on the floor.
- A canvas dust-mote field (devicePixelRatio-aware) whose particles drift upward,
  twinkle, and brighten the closer they are to the light source.
- Gothic-arch window framing via clip-path polygon; faint masked stone-block grid
  backdrop; a diagonal highlight "sweep" masked across the lead lines.
- Pointer-driven parallax/tilt on the whole glass layer with eased requestAnimationFrame.
- Full prefers-reduced-motion fallback (animations and parallax disabled).


INTENDED INTERACTION MODEL
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- Ambient, always alive: the halo pulses, the ray cone rotates, the floor pool
  breathes, dust motes drift, and a highlight sweeps the lead lines on infinite
  loops so the window feels like real shifting daylight even when idle.
- Pointer move (mouse or touch) over the viewport nudges the entire glass layer
  toward the cursor with eased rotation + translation, giving the glass depth and
  a subtle parallax against the stone frame.
- The light pool and glow intensify/relax together on their pulse cycle, so the
  room appears to brighten and dim as though weather moves outside.
- Responsive: the window stage scales by the smaller of viewport width/height and
  caps at 640px, keeping the arch perfectly square from 320px to 4K; type and
  spacing use fluid clamp() values throughout.
- Reduced-motion users get a still, static window with glow and rays set to a
  fixed state and no parallax or dust drift.