[style] .back-top fixes for larger screens
[style] .back-top proportions
[style] .site-footer proportion fix for large screens
[style] CSS reorganization (joining header and footer styles)
[style] [structure] new .alt-nav (back-top plus home)
[style] [fix] proportion and stroke adjustments – .back-home svg
[style] [fix] .back-home logo svg fix
[style] larger .alt-nav; reversed temporary colors
[style] .back-home svg padding adjustment