Window Shade

A cabin window with a shade you pull down by hand. The panel stays wherever it is let go, and the whole cabin crosses from a white ground to a near-black one as it comes, so half way down is a place to stop rather than a moment between two states.

Key insight: the theme is not a switch, it is the position of a control. The stage carries one number and every tone on it is a color-mix between one of the site's light tokens and its inverse-* twin at that number, so a deliberately light-only design gets a light and dark crossing without gaining a second theme. In oklab rather than sRGB, or the ramp is already dark for most of its travel.

Text is the one thing on the stage that cannot interpolate. A colour crossing from dark to light passes through the ground it is sitting on, and the ground is crossing the other way at the same time, so the two meet: the readout and the wall are the same value at half travel. It steps over 0.04 of the travel instead, where the two sides measure 4.2 and 4.0 against a wall that is 13.2 and 19.0 at the ends.

What holds the dark state is a gap rather than an effect. The panel is a couple of pixels narrower than the pane, which is the clearance it needs to slide at all, so a seated shade leaves two hairlines of daylight down its sides and a stage that would otherwise finish as an empty rectangle finishes as a closed shade in a dark cabin.

The cabin is line art and the only soft things in it are light: the pool on the wall, the falloff away from it, the bloom under the panel's foot and that leak. A panel joint in the sidewall is a groove rather than a tone, since a shadow carries it on the light wall and a lit lip carries it on the dark one, which is the one line here that escapes the flip.

Outside the glass the split is by distance instead, and nothing out there is a shape. The cloud is feTurbulence rather than the row of white ovals it started as, since a lump reads as a cartoon at any falloff and cloud is made of turbulence, not of ovals. The sun is a bloom with no disc in it, the wing reads by tone rather than by an outline round it, and a vignette and a film grain over the pane tie the three layers into one image. Two decks drift at a 2.8 ratio, which is what makes the parallax read as depth rather than as one thing moving. All of it then sits behind one blur, since a view drawn this precisely competes with the panel that is the actual demo, and the inner pane of a cabin window is scratched acrylic anyway: the sheen, the vignette and the grain stay sharp, being the glass rather than what is past it.

Grab and pull, not aim and jump, which is why this is not a native range the way the signature player's scrubber is: a range moves its thumb to the click, and a shade that leaps to meet your finger is not a shade. The cost is spelling out the keys. A phone keeps its scroll everywhere but the grip, and a tap on the glass throws the panel at whichever end it is not near.