2026-08-19 — Contrast band proportional scaling

Summary

The header contrast-band splines stay a full-bleed attractor. Geometry lives in a constant viewBox so zoom no longer shortens the path, and the homepage no longer grows a horizontal scrollbar from overshoot paint.

Highlights

  • Band box is --ftn-band-height: 6rem; SVG is width: 100% of the header. User space is a fixed 0 0 1440 96 box; the path always runs left edge to right edge plus a small overshoot for CSS drift.

  • Wavelength is a fraction of viewBox width (constant cycle count). Amplitude is a fraction of band height. preserveAspectRatio="none" maps that box to the layout size so zoom cannot letterbox empty space on the right.

  • ResizeObserver (and resize) only changes sample density from svg.clientWidth. It does not shrink viewBox or the right endpoint to CSS innerWidth.

  • Stroke uses vector-effect: non-scaling-stroke for thickness only. html/body use overflow-x: clip so drift overshoot cannot create a page scrollbar; the band still overflows vertically over the header seam.