Glass Pen Nib

Lumen pack asset: a pen nib in frosted, halftone-printed glass, hovering over a separate base bar. Every few seconds it taps down: the bar squashes, the slit flexes open, and the nib springs back up. Raymarched in WebGL with refraction, so the slit and breather hole show their inner walls. Five tints or your own colors. Zero dependencies; any number share one WebGL context.