- Shipped
- September 5, 2026 at 7:24 PM UTC
- Author
- Kamo
- Commit
- 6810799
The sheen now dies completely at the top-right and bottom-left corners and peaks, at half opacity, over the top-left and bottom-right. Each revolution reads as two episodes that rise and fall across a corner rather than one continuous lap, and the corner it dies on is the one the ribbon occupies, so the two never compete. Implemented as a static mask on the wrappers rather than a keyframed opacity, because the angle at which a corner sits depends on the pane's aspect ratio: 58 degrees off vertical at 1440x900, 24 at 390x844. Timed opacity would need retiming per viewport, and would drift the moment the window was resized. `to bottom right` does that geometry itself — CSS places the two corners the gradient line does not run through, here the top-right and the bottom-left, at exactly the 50% stop whatever the shape of the box, so a transparent stop at 50% is transparent at both by construction. Being static, it also costs nothing per frame; the mask is applied once and the spin underneath it is still the only thing that moves. The rim needed a nested element to carry it. Its ring already occupies .kamo-glimmer-edge's own mask property, and stacking the envelope on as a third layer would mean a three-way mask-composite list — whose failure mode, if a browser drops the list as invalid, is every layer compositing with `add` and the gradient filling the entire pane. A nested element multiplies the two masks instead and degrades to nothing worse than a missing fade. Measured by sampling the gap pixel just outside each corner at the moment the core reaches it, against the same pixel with the glimmer removed. Luma delta: top-left +24.0, bottom-right +24.0, top-right 0.0, bottom-left 0.0 — half of the +48.9 the full-strength envelope gave, and gone entirely at the other two.