Size rules were forcing display:inline-block on both footer logos with
higher specificity than the night-hide rule. Decouple display toggle,
raise selector weight, align dark hooks with header/theme.js, and drop
unused part-1 light/dark logo-img rules.
Make show-slide header overlay the hero, dual-class nav/footer shells
toward zibll selectors, and add a small footer layout bridge for logo,
contact, and float buttons.