- Replace the baked-in full-logo PNG in the header with the standalone
Bildmarke (SVG) + live Apex Brush wordmark; "Regenbogen" uses the
rainbow gradient (same as headings)
- Responsive: icon-only on mobile, two-line wordmark on sm–lg, one-line
on xl; move nav breakpoint md->lg so the two-line wordmark doesn't
collide with the inline nav (tablet uses the menu button)
- Footer and elsewhere keep the full logo
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>