Signed-off-by: Matt Bruce <mbrucedogs@gmail.com>

BusinessCard/Design/DesignConstants.swift

@@ -8,10 +8,53 @@
 import SwiftUI
 import Bedrock
 
+// MARK: - Device Size Tier
+
+/// Categorizes devices by screen size for adaptive layouts.
+/// Primarily used to adjust card dimensions on smaller iPhones and constrain width on iPad.
+enum DeviceSizeTier {
+    case compact   // iPhone SE, Mini, older 4.7" devices (height < 700pt)
+    case standard  // Regular iPhone (height 700-850pt)
+    case large     // Pro Max, Plus models (height > 850pt)
+    case tablet    // iPad
+    
+    /// The current device's size tier based on screen dimensions.
+    static var current: DeviceSizeTier {
+        let bounds = UIScreen.main.bounds
+        let height = max(bounds.width, bounds.height)
+        let width = min(bounds.width, bounds.height)
+        
+        // iPad detection: width >= 768pt in portrait
+        if width >= 768 {
+            return .tablet
+        }
+        
+        switch height {
+        case ..<700:
+            return .compact
+        case ..<850:
+            return .standard
+        default:
+            return .large
+        }
+    }
+    
+    /// Whether the current device is an iPad.
+    static var isTablet: Bool {
+        current == .tablet
+    }
+    
+    /// Whether the current device is a compact iPhone (SE, Mini).
+    static var isCompact: Bool {
+        current == .compact
+    }
+}
+
 // MARK: - App-Specific Sizes
 
 extension Design {
     /// BusinessCard-specific size constants.
+    /// Some values adapt based on device size tier.
     enum CardSize {
         static let cardWidth: CGFloat = 320
         static let cardHeight: CGFloat = 340
@@ -20,7 +63,17 @@ extension Design {
         static let avatarLarge: CGFloat = 80
         static let avatarOverlap: CGFloat = 40
         static let logoSize: CGFloat = 64
-        static let bannerHeight: CGFloat = 240
+        
+        /// Banner height adapts to device size to prevent dominating small screens.
+        static var bannerHeight: CGFloat {
+            switch DeviceSizeTier.current {
+            case .compact:  return 180
+            case .standard: return 210
+            case .large:    return 240
+            case .tablet:   return 240
+            }
+        }
+        
         static let qrSize: CGFloat = 200
         static let qrSizeLarge: CGFloat = 260
         static let colorSwatchSize: CGFloat = 40
@@ -29,10 +82,14 @@ extension Design {
         static let widgetPhoneHeight: CGFloat = 120
         static let widgetWatchSize: CGFloat = 100
         static let floatingButtonSize: CGFloat = 56
-        /// Bottom offset for floating button above tab bar.
-        static let floatingButtonBottomOffset: CGFloat = 72
         /// Aspect ratio for logo container (3:2 landscape).
         static let logoContainerAspectRatio: CGFloat = 3.0 / 2.0
+        
+        /// Maximum card width to prevent stretching on iPad.
+        /// On iPhone this returns nil (no constraint needed).
+        static var maxCardWidth: CGFloat? {
+            DeviceSizeTier.isTablet ? 500 : nil
+        }
     }
 }
 

BusinessCard/Views/CardEditorView.swift

@@ -1082,6 +1082,8 @@ private struct CardPreviewSheet: View {
         NavigationStack {
             ScrollView {
                 BusinessCardView(card: card)
+                    .frame(maxWidth: Design.CardSize.maxCardWidth)
+                    .frame(maxWidth: .infinity)
                     .padding(Design.Spacing.large)
             }
             .background(Color.AppBackground.base)

BusinessCard/Views/CardsHomeView.swift

@@ -98,7 +98,9 @@ private struct CardPageView: View {
         ScrollView {
             VStack(spacing: Design.Spacing.large) {
                 BusinessCardView(card: card)
+                    .frame(maxWidth: Design.CardSize.maxCardWidth)
             }
+            .frame(maxWidth: .infinity)
             .padding(.horizontal, Design.Spacing.large)
             .padding(.vertical, Design.Spacing.xLarge)
         }

BusinessCard/Views/RootTabView.swift

@@ -9,10 +9,19 @@ struct RootTabView: View {
     var body: some View {
         @Bindable var appState = appState
         
-        ZStack(alignment: .bottom) {
         TabView(selection: $appState.selectedTab) {
             Tab(String.localized("My Cards"), systemImage: "rectangle.stack", value: AppTab.cards) {
                 CardsHomeView()
+                    .safeAreaInset(edge: .bottom, spacing: 0) {
+                        // Floating share button positioned above tab bar
+                        if !appState.cardStore.cards.isEmpty {
+                            FloatingShareButton {
+                                showingShareSheet = true
+                            }
+                            .frame(maxWidth: .infinity)
+                            .padding(.bottom, Design.Spacing.small)
+                        }
+                    }
             }
 
             Tab(String.localized("Contacts"), systemImage: "person.2", value: AppTab.contacts) {
@@ -23,14 +32,6 @@ struct RootTabView: View {
                 WidgetsView()
             }
         }
-            
-            // Floating share button - only shown on cards tab when cards exist
-            if appState.selectedTab == .cards && !appState.cardStore.cards.isEmpty {
-                FloatingShareButton {
-                    showingShareSheet = true
-                }
-            }
-        }
         .sheet(isPresented: $showingShareSheet) {
             ShareCardView()
         }
@@ -62,7 +63,6 @@ private struct FloatingShareButton: View {
         }
         .accessibilityLabel(String.localized("Share"))
         .accessibilityHint(String.localized("Opens the share sheet to send your card"))
-        .padding(.bottom, Design.CardSize.floatingButtonBottomOffset)
     }
 }