Optimize header link spacing and add visual feedback for active pages:
- Reduce link padding and gap for more compact navigation
- Shorten German labels: "In Saison" to "Saison", "Stichwörter" to "Tags"
- Remove "Tipps" section from navigation menu
Add active page highlighting across all layouts:
- Highlight current page links in red (matching hover color)
- Desktop: animated red underline that smoothly slides between links
- Mobile: static red underline for active links in hamburger menu
- Underline aligns precisely with text width (excludes padding)
Improve transitions:
- Fix color transition to only animate color, not layout properties
- Disable underline transition during window resize to prevent lag
- Underline updates immediately on resize for perfect alignment