CSS gradient generator

Builds a `linear-gradient`, `radial-gradient` or `conic-gradient` with as many colour stops as you want, previewed live, and gives you the CSS that produced exactly what you are looking at.

The angle in a CSS linear gradient is not the angle you may expect. `0deg` points **up** and the angle turns clockwise, so `90deg` runs left to right and `180deg` runs top to bottom. That is the opposite convention to most maths and to SVG, and it is why a gradient copied from a design tool often comes out mirrored. The part worth understanding is interpolation. A gradient between two colours is a straight line through a colour space, and by default that space is sRGB — which is why blue to yellow passes through a muddy grey rather than through green. The fix is to name a better space: `linear-gradient(in oklch, blue, yellow)` keeps the lightness even and passes through colours a person would expect. Support is now broad, and the difference on a two-colour blend is dramatic. One thing to watch: a gradient with hard stops — two stops at the same position — makes stripes rather than a blend, and that is the standard way to build a striped or split background without an image. Put two stops at 50% with different colours and you have a two-tone panel.