v0.13.20

Changes

• Footer brand row follows the page theme and reuses the hero WebP (quieter cover + left fade). The copyright strip stays navy.
• Header and reading-progress track are opaque paper, so scrolling copy no longer shows through the magenta rule.
• Footer tagline stays on one line on desktop.

Hugo Modules: hugo mod get github.com/splunk/hugo-theme-splunk-workshop@v0.13.20