TITLE Tangram Menagerie PROMPT A tangram puzzle game: the seven classic pieces (two large triangles, one medium triangle, two small triangles, a square, a parallelogram, all cut from one square) and a set of silhouettes to fill. Built in SVG with precise geometry. Concept: seven shapes, a whole zoo; the reward for solving is that the animal comes alive. Mood: playful, bright, mid-century children's-book modern. Palette: warm paper #F7F3E8; pieces in flat colours: vermilion #E4572E, turquoise #17BEBB, sun yellow #FFC914, leaf green #76B041, plus charcoal-aubergine #2E282A (used for silhouettes, type, and two of the pieces in lighter tints: #5A5257 and #8C8287, and one small triangle in the charcoal itself, so all seven pieces are distinguishable). Light page, flat colour, a faint paper grain, soft short shadows under lifted pieces. Layout: the work mat in the centre holds the target silhouette (solid charcoal at 18% tint with a subtle dotted outline); the seven pieces start in a loose scattered arrangement around or below it (on phones: in a tray beneath, scaled to fit); a puzzle selector on the left as a column of tiny silhouette thumbnails with names; a header with the title in big, chunky, friendly geometric type (Futura/"Century Gothic"/"Trebuchet MS", bold, lowercase: "tangram menagerie") where the letter counters are filled with little triangles. Puzzles (at least eight, each defined by exact piece placements on the classic unit grid so the silhouette is a true tangram union and the solution check is exact): swan, cat, rabbit, fish, dancer, sailing boat, house, bird in flight. Solution detection must be shape-based, not piece-identity-based: compare the covered area with the silhouette (e.g. rasterise/sample points or polygon tests with tolerance), so interchangeable pieces and alternative solutions count; the two orientations of the parallelogram are handled with a flip. Interaction: drag a piece (pointer events with capture; the piece lifts with scale 1.04 and a deeper shadow); rotate in 45° steps by tapping/clicking a selected piece's rotate handle, mouse wheel while dragging, the R key, or a two-finger twist; flip the parallelogram with F or a flip handle. Pieces snap magnetically when a vertex or edge comes within a few pixels of the silhouette's valid positions or of other pieces' vertices (snap with a quick spring settle and a tiny "click" squash). Keyboard: Tab cycles pieces, arrows move, R rotates, F flips. A "hint" control shows the outline of one unplaced piece in its place for two seconds (dotted line drawing itself); a "start over" control scatters the pieces with a playful toss. Signature moment: completion. When the silhouette is fully covered, the seams between pieces glow briefly, then the assembled animal animates as a creature while still made of its seven pieces: the swan glides across the mat with its neck piece bobbing and ripple lines beneath; the cat's tail triangle swishes and it blinks a drawn eye; the rabbit hops with ears flicking; the fish swims with tail wagging and bubbles; the boat rocks on drawn waves; the dancer sways with arms waving and notes drifting up; the house pops its roof like a lid, lights its windows and puffs smoke; the bird flaps past speed lines. A hand-lettered style caption appears ("a swan, from seven pieces, in 1 minute 12") and a small stamp is added to a progress row of eight animal stamps. Then "next" slides the pieces apart with a staggered spring and loads the next silhouette. Entrance: the seven pieces begin as the original square in the centre, hold for half a second, then burst apart into the scatter and the first silhouette draws on: a strong first three seconds. Details: a move counter and timer in tiny tabular numerals; the unused-thumbnail silhouettes wiggle on hover; pieces show a subtle grain direction so rotations are legible. Optional sound toggle (off by default): soft wooden clicks on snap and a short pentatonic flourish on completion. Reduced motion: no burst or creature animation; solved state shown with a simple colour flash and caption. DESCRIPTION A bright, paper-coloured tangram table in the manner of a mid-century picture book. The title is drawn letter by letter in chunky geometric strokes so that every counter and arch can hold a small coloured triangle. Seven flat-coloured wooden pieces begin as the classic square, burst apart into a loose scatter, and a pale dotted silhouette draws itself onto the work mat. The viewer drags, turns and flips the pieces until the shape is covered; the seams then glow, the silhouette fades, and the finished figure wakes up while still visibly made of its seven pieces: a swan glides over ripples, a cat blinks and swishes its tail, a rabbit hops, a fish wags through bubbles, a dancer sways, a boat rocks on waves, a house puffs smoke, a bird flaps. A lettered caption reports the time, and a vermilion stamp is pressed into a row of eight. VISUAL TECHNIQUES - Inline SVG stage with exact tangram geometry on square and diagonal unit lattices; every silhouette is a true union of the seven pieces - Silhouette outline computed in the page by splitting and cancelling shared edges, drawn as a dotted line revealed through an animated stroke mask - Shape-based solution test by sampling points of the silhouette against the pieces' polygons, so interchangeable pieces and alternative solutions count - Hand-rolled spring physics for position, rotation, lift, flip and snap squash, with staggered toss choreography - Creature animation by composing body and limb transforms over the pieces the viewer actually placed, plus small drawn extras (eyes, ripples, bubbles, waves, smoke, notes) - Title lettering constructed from SVG strokes with triangles popping into the counters - Procedural paper grain tile drawn once to canvas, wood-grain lines clipped to each piece, blurred short shadows that deepen on lift - Print-style flat controls with hard offset shadows, dotted rules, stamp marks and tabular numerals - Optional synthesised sound: wooden clicks and a pentatonic flourish INTERACTION MODEL Drag any piece with mouse, pen or finger; it lifts, follows the pointer and, on release, snaps magnetically to silhouette corners or other pieces' corners with a small squash. A selected piece shows a rotate handle (and a flip handle on the parallelogram); the mouse wheel, the R key or a two-finger twist turn it in 45 degree steps, and F flips the parallelogram. With the keyboard, Tab cycles through pieces, arrow keys move (Shift for fine steps), R rotates, F flips and Enter drops with a snap. "hint" draws the dotted outline of one unplaced piece for two seconds; "start over" tosses the pieces back into a scatter and resets the move counter and timer; the sound button turns on clicks and the completion flourish. The column of thumbnails (a scrolling strip on phones, where pieces wait in a tray under the mat) switches puzzles. Covering the silhouette triggers the glow, the living animal, the caption and a stamp; "next" calms the creature, tosses the pieces apart and draws the next silhouette. With reduced motion the entrance burst and creature are replaced by an immediate layout, a colour flash and the caption.