Apple HIG Design Principles and Mindsets (12 Core Principles / Fluid Interfaces / Intentional Design / Multisensory / ML Experiences)
The most 'methodology-focused' layer of Apple's design system — it does not talk about which component to use, but about why. Design philosophy (why Human Interface is called Human · design serves people · 6 qualities of great design) + 12 core design principles (Wayfinding / Feedback / Visibility / Consistency / Mental Model / Proximity / Grouping / Mapping / Affordance / Progressive Disclosure / 80-20 / Symmetry) + 5 elements of Intentional Design (radical simplification / deep understanding / extreme focus / personal connection / direct communication) + Fluid Interfaces (dynamic motion vs timed animation · elastic physics · projected momentum · 6 sub-principles) + complete workflow from concept to interface (structure → navigation → content → visuals, with a vinyl record App hands-on example) + multisensory design (sound design · 3 haptic principles · transient/continuous · technical constraints) + multilingual, intelligence and ML experiences (data/metrics · system intelligence journey) + 60-minute rapid prototyping.