GroundRules: Skill for Claude Code

iOS Design Guidelines for iPhone

Comprehensive rules derived from Apple's Human Interface Guidelines. Apply these when building, reviewing, or refactoring any iPhone app interface.

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1. Layout & Safe Areas

Impact: CRITICAL

Rule 1.1: Minimum 44pt Touch Targets

All interactive elements must have a minimum tap target of 44x44 points. This includes buttons, links, toggles, and custom controls.

Correct:

Button("Save") { save() }
    .frame(minWidth: 44, minHeight: 44)

Incorrect:

// 20pt icon with no padding — too small to tap reliably
Button(action: save) {
    Image(systemName: "checkmark")
        .font(.system(size: 20))
}
// Missing .frame(minWidth: 44, minHeight: 44)

Rule 1.2: Respect Safe Areas

Never place interactive or essential content under the status bar, Dynamic Island, or home indicator. Use SwiftUI's automatic safe area handling or UIKit's safeAreaLayoutGuide.

Correct:

struct ContentView: View {
    var body: some View {
        VStack {
            Text("Content")
        }
        // SwiftUI respects safe areas by default
    }
}

Incorrect:

struct ContentView: View {
    var body: some View {
        VStack {
            Text("Content")
        }
        .ignoresSafeArea() // Content will be clipped under notch/Dynamic Island
    }
}

Use .ignoresSafeArea() only for background fills, images, or decorative elements — never for text or interactive controls.

Rule 1.3: Primary Actions in the Thumb Zone

Place primary actions at the bottom of the screen where the user's thumb naturally rests. Secondary actions and navigation belong at the top.

Correct:

VStack {
    ScrollView { /* content */ }
    Button("Continue") { next() }
        .buttonStyle(.borderedProminent)
        .padding()
}

Incorrect:

VStack {
    Button("Continue") { next() } // Top of screen — hard to reach one-handed
        .buttonStyle(.borderedProminent)
        .padding()
    ScrollView { /* content */ }
}