NetBox's rack elevation stylesheet uses CSS custom properties, which WeasyPrint and cairosvg cannot resolve, so empty slots fell back to a black fill. Replace the embedded stylesheet with fixed light-theme colors, add equivalent presentation attributes as a fallback and drop the hover-only "Add Device" labels. Bump version to 0.3.1. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>