Gradient Track is a browser game. A palette is selected by its two endpoint hex codes, followed by 30 or 100 cards. Both counts use the same track with fixed endpoint colors and 100 intervening slots. Cards arrive in batches of five, with each new batch dealt after all five are placed. Dragging a card to a track position places it.
Cards follow the finger along the track. Placement in an occupied slot shifts the existing card one slot. Holding a placed card for 0.3 seconds removes it for repositioning. On mobile, pinching zooms and moving two fingers together pans. On desktop, the mouse wheel or trackpad zooms, dragging empty space pans, and a double click resets the view. A round may be scored at any time.
Results display the correct gradient and connect each card to its correct position. Accuracy weights position and order equally, using the round count as denominator. Position scores decrease with distance: zero slots earns full credit; 12 or more, or unplaced cards, earn zero. Order counts correctly ordered pairs with both cards placed. Full placement, correct order, and every card within two slots constitute a perfect result and trigger a special animation.
Best records for each palette are stored on the device, separately for 30 and 100 cards. Four palettes are currently available, with more to be added. Results generate a shareable image with two styles, Swatch Book and Full Gradient, and two content options, Gradient Strip and Game State. Sharing includes the image, result text, and a link.