SKILL.md
iOS 26 Platform
iOS 26 introduces Liquid Glass, Apple's next-generation material design system that dynamically bends light, moves organically, and adapts automatically across all platforms.
Overview
iOS 26 modernizes UI with new materials (Liquid Glass), SwiftUI APIs (WebView, Chart3D, @Animatable), and advanced features (@BackoffAnimation, free-form windows). The core principle: modern UI gets updated automatically at compile time; most Liquid Glass benefits are "free" from recompiling with Xcode 26.
Reference Loading Guide
ALWAYS load reference files if there is even a small chance the content may be required. It's better to have the context than to miss a pattern or make a mistake.
| Reference | Load When |
|---|---|
| [Liquid Glass](references/liquid-glass.md) | Implementing glass effects, choosing Regular vs Clear variants, or understanding visual properties |
| [Automatic Adoption](references/automatic-adoption.md) | Understanding what iOS 26 changes automatically vs what requires code |
| [SwiftUI APIs](references/swiftui-apis.md) | Using WebView, Chart3D, @Animatable, AttributedString, or new view modifiers |
| [Toolbar & Navigation](references/toolbar-navigation.md) | Customizing toolbars with spacers, morphing, glass button styles, or search |
| [Backward Compatibility](references/backward-compat.md) | Supporting iOS 17/18 alongside iOS 26, or using UIDesignRequiresCompatibility |
Core Workflow
- Check deployment target — iOS 26+ required for Liquid Glass
- Recompile with Xcode 26 — Standard controls get glass automatically
- Identify navigation layer — Apply glass to tab bars, toolbars, navigation (not content)
- Choose variant — Regular (95% of cases) or Clear (media-rich backgrounds only)
- Add @available guards — For backward compatibility with iOS 17/18
- Test accessibility — Verify Reduce Transparency, Increase Contrast, Reduce Motion
Common Mistakes
- Ignoring backward compatibility — Targeting iOS 26+ without
@availableguards breaks iOS 17/18 support. Always useif #available(iOS 26, *)for Liquid Glass or new APIs.
- Over-using glass effect — Applying glass to content areas, not just navigation, creates visual noise. Glass works for: tab bars, toolbars, sheets, navigation. NOT for content areas.
- Animation performance issues — Liquid Glass animations can be expensive. Respect Reduce Motion accessibility setting and profile with Instruments 26 before shipping.
- Assuming Clear variant looks good — Clear is for media-rich backgrounds only (photos, video). Regular variant is correct 95% of the time. Only use Clear if you explicitly need the ultra-transparency.
- Not testing on actual devices — Simulator rendering differs from hardware. Test glass effects on iPhone 15 Pro, iPad, and Mac to verify visual quality.
- Using old UIView patterns with new glass — Mixing UIView-based navigation with iOS 26 glass creates inconsistent appearances. Migrate fully to SwiftUI or wrap carefully with UIViewRepresentable.