Key sheet: gate the How Best Value row on the feature, like the More info row

The More info row went inside the Best Value card's `if let fuelSavings`, but the
Key sheet row was left ungated, so it stayed visible with Best Value switched off.
It is now gated on `fuelSavingsSettings.isConfigured` — exactly the condition
`savingsForStation` uses, i.e. the same gate as the card — so the two rows appear
and disappear together.

Verified on the simulator by toggling Best Value in Settings and scrolling the Key
sheet to its end (four drags, sheet still up and its footer in view each time):
- OFF: the row is absent at every scroll position, and the More info sheet shows
  neither the card nor the row;
- ON: the row is present, and the More info card and its row are both back.
210 tests pass; Release builds.

FuelBoard/HowBestValueSheet.swift

@@ -0,0 +1,69 @@
+import SwiftUI
+
+/// The "How Best Value works" explanation as its own sheet.
+///
+/// It used to sit inline in the Key sheet as a `Section`; it is one shared view
+/// now so the Key sheet and the More info sheet can both open it, and the copy is
+/// unchanged (the same `Localizable.strings` keys are reused — the old section
+/// header string is the sheet's title).
+struct HowBestValueSheet: View {
+    @Environment(\.dismiss) private var dismiss
+
+    var body: some View {
+        NavigationStack {
+            List {
+                Section {
+                    VStack(alignment: .leading, spacing: 10) {
+                        Text("Best Value compares each station with the closest one. It works out what you could save at the pump, then takes off the fuel used for the extra return journey.")
+                        Text("Your fill-up amount and MPG are used to show whether you could save overall.")
+                        Text("Results are marked “Approx.” until road distances are available.")
+                            .foregroundStyle(.secondary)
+                    }
+                    .font(.subheadline)
+                    .padding(.vertical, 4)
+                }
+            }
+            .navigationTitle("How Best Value works")
+            .navigationBarTitleDisplayMode(.inline)
+            .toolbar {
+                ToolbarItem(placement: .confirmationAction) {
+                    Button("Done") { dismiss() }
+                }
+            }
+        }
+        .presentationDetents([.fraction(0.42)])
+        .presentationBackground(Color(UIColor.systemGroupedBackground))
+    }
+}
+
+/// The row that opens `HowBestValueSheet`. A tappable row with a chevron, like
+/// the other rows in both sheets. `.buttonStyle(.plain)` keeps it from becoming a
+/// row-wide tap target that could swallow a neighbouring control (see the
+/// two-buttons-in-one-row rule).
+struct HowBestValueRow: View {
+    let action: () -> Void
+
+    var body: some View {
+        Button(action: action) {
+            HStack(spacing: 8) {
+                Text("How Best Value works")
+                Spacer(minLength: 8)
+                Image(systemName: "chevron.forward")
+                    .font(.footnote.weight(.semibold))
+                    .foregroundStyle(.tertiary)
+            }
+        }
+        .buttonStyle(.plain)
+    }
+}
+
+#if DEBUG
+/// QA hook support: `-showBestValueInfo` opens this sheet without a tap, so it can
+/// be screenshotted (simctl has no tap command) — the same pattern as
+/// `-showKeySheet` / `-showDetail`.
+enum BestValueInfoQA {
+    static var isRequested: Bool {
+        ProcessInfo.processInfo.arguments.contains("-showBestValueInfo")
+    }
+}
+#endif

FuelBoard/OnboardingView.swift

@@ -98,7 +98,7 @@ struct OnboardingView: View {
     private var welcomePage: some View {
         VStack(spacing: 0) {
             Spacer()
-            AnimatedOnboardingIcon(tint: .accentColor) {
+            AnimatedOnboardingIcon(tint: .accentColor, showsHalo: false) {
                 // The app icon itself, with the standard iOS rounded-corner
                 // treatment (~22% of the size), so onboarding matches the
                 // Home Screen.
@@ -393,6 +393,9 @@ struct AnimatedOnboardingIcon<Content: View>: View {
 
     let tint: Color
     var motion: Motion = .gentle
+    /// The soft circle behind the glyph. The welcome page turns it off: it shows
+    /// the app icon itself and reads better with no container around it.
+    var showsHalo: Bool = true
     @ViewBuilder var content: Content
 
     @State private var settled = false
@@ -402,16 +405,18 @@ struct AnimatedOnboardingIcon<Content: View>: View {
 
     var body: some View {
         ZStack {
-            Circle()
-                .fill(tint.opacity(0.10))
-                .frame(width: 108, height: 108)
-                .scaleEffect(settled ? 1.0 : 0.94)
+            if showsHalo {
+                Circle()
+                    .fill(tint.opacity(0.10))
+                    .frame(width: 108, height: 108)
+                    .scaleEffect(settled ? 1.0 : 0.94)
 
-            Circle()
-                .stroke(tint.opacity(0.18), lineWidth: 1)
-                .frame(width: 118, height: 118)
-                .scaleEffect(settled ? 1.03 : 0.97)
-                .opacity(settled ? 1.0 : 0.55)
+                Circle()
+                    .stroke(tint.opacity(0.18), lineWidth: 1)
+                    .frame(width: 118, height: 118)
+                    .scaleEffect(settled ? 1.03 : 0.97)
+                    .opacity(settled ? 1.0 : 0.55)
+            }
 
             content
                 .scaleEffect(iconScale)

FuelBoard/StationDetailView.swift

@@ -29,10 +29,13 @@ struct StationDetailView: View {
     var onToggleFavourite: (() -> Void)? = nil
     @Environment(\.dismiss) private var dismiss
     @State private var showingReportIssueConfirmation = false
-    /// Transient "Copied" confirmation on the Address row. Cleared by a task so
+    /// Transient "Postcode copied" confirmation on the Address row. Cleared by a task so
     /// the caption fades out on its own.
     @State private var showingCopied = false
     @State private var copyResetTask: Task<Void, Never>?
+    /// The "How Best Value works" sheet, opened from the row at the bottom of the
+    /// Best Value card (the Key sheet opens the same shared view).
+    @State private var showBestValueInfo = false
 
     private let reportIssueURL = URL(string: "https://www.gov.uk/guidance/report-an-error-in-fuel-prices-or-forecourt-details")!
 
@@ -118,12 +121,92 @@ struct StationDetailView: View {
                         .accessibilityHint(String(localized: "Opens Apple Maps with driving directions",
                                                   comment: "Accessibility hint for the tappable map preview in the More info sheet"))
                     }
-                    .listRowInsets(EdgeInsets())
-                }
-                // The two station actions live in their OWN section, so they
-                // render as a separate card BELOW the map instead of sharing the
-                // map's card and looking attached to the map tap target.
-                Section {
+                    // No hairline between the map and the Address row: the map
+                    // already reads as its own block, so the line only added
+                    // clutter. The Address/Distance and Distance/actions lines
+                    // stay.
+                    .listRowSeparator(.hidden, edges: .bottom)
+                    // The map, the address, the distance, any notices and the two
+                    // station actions all share ONE card (the list's own row
+                    // hairlines separate them), so no hand-rolled Divider here —
+                    // adding one would double the line.
+                    //
+                    // The station name is NOT repeated: the sheet header already
+                    // shows it.
+                    //
+                    // The whole row is a copy control: it puts JUST the postcode
+                    // on the clipboard so it can be pasted into another
+                    // navigation app. The copy glyph sits ON the address line,
+                    // and the "Postcode copied" confirmation is a capsule that floats OVER
+                    // THIS ROW — it confirms the address, so it must not hover
+                    // over the map. It is an overlay, so nothing moves while it is
+                    // up, and `allowsHitTesting(false)` keeps the row tappable
+                    // through the capsule.
+                    Button {
+                        copyPostcode()
+                    } label: {
+                        HStack(alignment: .firstTextBaseline, spacing: 8) {
+                            Text("Address")
+                            Spacer(minLength: 8)
+                            Text(addressLine)
+                                .multilineTextAlignment(.trailing)
+                                .foregroundStyle(.secondary)
+                            // Stays the plain copy glyph — the capsule carries
+                            // the confirmation, so swapping this to a checkmark
+                            // would say it twice.
+                            Image(systemName: "doc.on.doc")
+                                .font(.footnote.weight(.semibold))
+                                .foregroundStyle(.secondary)
+                        }
+                    }
+                    .buttonStyle(.plain)
+                    .disabled(postcodeForCopying.isEmpty)
+                    .accessibilityLabel(String(localized: "Address: \(addressLine)",
+                                               comment: "Accessibility label for the address row in the More info sheet"))
+                    .accessibilityHint(postcodeForCopying.isEmpty
+                        ? ""
+                        : String(localized: "Copies the postcode",
+                                 comment: "Accessibility hint for the address row in the More info sheet"))
+                    // Horizontally centred over the address line itself.
+                    .overlay(alignment: .center) {
+                        if showingCopied {
+                            HStack(spacing: 4) {
+                                Image(systemName: "checkmark")
+                                Text("Postcode copied")
+                            }
+                            .font(.footnote.weight(.semibold))
+                            .foregroundStyle(.green)
+                            .padding(.horizontal, 10)
+                            .padding(.vertical, 6)
+                            // A material base keeps it legible where the tint
+                            // alone (the notice-capsule recipe) washes out.
+                            .background {
+                                Capsule()
+                                    .fill(.regularMaterial)
+                                    .overlay(Capsule().fill(Color.green.opacity(0.22)))
+                            }
+                            .allowsHitTesting(false)
+                            .accessibilityHidden(true)
+                            .transition(.opacity)
+                        }
+                    }
+                    if let location {
+                        let distance = FuelStore.stationDistanceDisplay(
+                            station: station, userLat: location.lat, userLng: location.lng
+                        )
+                        LabeledContent("Distance", value: distance.labelWithReturn(unit: distanceUnit))
+                            .monospacedDigit()
+                    }
+                    ForEach(StationNotice.notices(for: station)) { notice in
+                        Label(notice.title, systemImage: notice.symbolName)
+                            .font(.subheadline.weight(.semibold))
+                            .foregroundStyle(.orange)
+                            .padding(.horizontal, 10)
+                            .padding(.vertical, 6)
+                            .background(Capsule().fill(Color.orange.opacity(0.14)))
+                    }
+                    // The two station actions are the LAST row of the card: half
+                    // the width each, on one line, below Address and Distance.
                     HStack(spacing: 12) {
                         Button {
                             openDirections()
@@ -145,65 +228,6 @@ struct StationDetailView: View {
                     // button its own hit area — the half-row frame above.
                     .buttonStyle(.borderless)
                 }
-                Section {
-                    // The station name is NOT repeated here: the sheet header
-                    // (navigationTitle, inline) already shows it, and the address
-                    // line below has any leading repeat of the name stripped, so
-                    // a "Name" row only said it twice.
-                    //
-                    // The whole row is a copy control: it puts JUST the postcode
-                    // on the clipboard so it can be pasted into another
-                    // navigation app. The copy glyph and its "Copied"
-                    // confirmation share a SECOND line that is always there, so
-                    // the confirmation can never reflow the address above it.
-                    Button {
-                        copyPostcode()
-                    } label: {
-                        VStack(alignment: .leading, spacing: 6) {
-                            HStack(alignment: .firstTextBaseline, spacing: 8) {
-                                Text("Address")
-                                Spacer(minLength: 8)
-                                Text(addressLine)
-                                    .multilineTextAlignment(.trailing)
-                                    .foregroundStyle(.secondary)
-                            }
-                            HStack(spacing: 4) {
-                                Spacer(minLength: 0)
-                                if showingCopied {
-                                    Text("Copied")
-                                        .foregroundStyle(.green)
-                                        .transition(.opacity)
-                                }
-                                Image(systemName: showingCopied ? "checkmark" : "doc.on.doc")
-                                    .foregroundStyle(showingCopied ? Color.green : Color.secondary)
-                            }
-                            .font(.footnote.weight(.semibold))
-                        }
-                    }
-                    .buttonStyle(.plain)
-                    .disabled(postcodeForCopying.isEmpty)
-                    .accessibilityLabel(String(localized: "Address: \(addressLine)",
-                                               comment: "Accessibility label for the address row in the More info sheet"))
-                    .accessibilityHint(postcodeForCopying.isEmpty
-                        ? ""
-                        : String(localized: "Copies the postcode",
-                                 comment: "Accessibility hint for the address row in the More info sheet"))
-                    if let location {
-                        let distance = FuelStore.stationDistanceDisplay(
-                            station: station, userLat: location.lat, userLng: location.lng
-                        )
-                        LabeledContent("Distance", value: distance.labelWithReturn(unit: distanceUnit))
-                            .monospacedDigit()
-                    }
-                    ForEach(StationNotice.notices(for: station)) { notice in
-                        Label(notice.title, systemImage: notice.symbolName)
-                            .font(.subheadline.weight(.semibold))
-                            .foregroundStyle(.orange)
-                            .padding(.horizontal, 10)
-                            .padding(.vertical, 6)
-                            .background(Capsule().fill(Color.orange.opacity(0.14)))
-                    }
-                }
                 // Only shown while Fuel Savings backs it. `fuelSavings` is nil
                 // when the feature is off — `savingsLookup` returns nil when it
                 // is not configured — so the heading cannot be left dangling
@@ -219,6 +243,13 @@ struct StationDetailView: View {
                     } header: {
                         Text("Best Value")
                     }
+
+                    // The explanation lives in its own sheet now, opened from this
+                    // row. The row sits INSIDE the `if let` so it carries the same
+                    // gate as the card above: no card, no row.
+                    Section {
+                        HowBestValueRow { showBestValueInfo = true }
+                    }
                 }
 
 #if DEBUG
@@ -244,6 +275,8 @@ struct StationDetailView: View {
             } message: {
                 Text("Are you sure you want to report an error in fuel prices or forecourt details? This will open in your chosen browser.")
             }
+            // Nested sheet: the More info sheet stays put behind the explanation.
+            .sheet(isPresented: $showBestValueInfo) { HowBestValueSheet() }
             .toolbar {
                 ToolbarItem(placement: .cancellationAction) {
                     Button("Done") { dismiss() }
@@ -263,12 +296,12 @@ struct StationDetailView: View {
                     )
                 }
             }
-            // The "Copied" fade-out task must not outlive the sheet.
+            // The "Postcode copied" fade-out task must not outlive the sheet.
             .onDisappear { copyResetTask?.cancel() }
 #if DEBUG
             // QA hook: `-qaCopyPostcode` runs the REAL copy on open, so the
             // clipboard value (read back with `xcrun simctl pbpaste`) and the
-            // "Copied" confirmation can be verified without a tap — simctl
+            // "Postcode copied" confirmation can be verified without a tap — simctl
             // cannot drive taps into the Simulator.
             .task {
                 guard ProcessInfo.processInfo.arguments.contains("-qaCopyPostcode") else { return }

FuelBoard/StationsView.swift

@@ -35,6 +35,11 @@ struct StationsView: View {
     /// info button in the header — keeps the list focused on stations.
     @State private var showKey = false
 
+    /// The "How Best Value works" sheet. The explanation used to be a section in
+    /// the Key sheet; it is its own sheet now, opened from a row at the bottom of
+    /// the Key sheet and from the More info sheet.
+    @State private var showBestValueInfo = false
+
     /// Station picked for the More-info sheet (tap action = showDetails).
     @State private var detailStation: FuelStation?
 
@@ -218,6 +223,18 @@ struct StationsView: View {
                 if ProcessInfo.processInfo.arguments.contains("-showKeySheet") {
                     showKey = true
                 }
+                // QA hook: `-showBestValueInfo` opens the Key sheet and then the
+                // explanation on top of it, so the copy can be screenshotted
+                // without a tap. It has to chain: the explanation's `.sheet` lives
+                // inside the Key sheet's content, so it cannot present while the
+                // Key sheet is shut.
+                if BestValueInfoQA.isRequested {
+                    showKey = true
+                    Task { @MainActor in
+                        try? await Task.sleep(nanoseconds: 1_200_000_000)
+                        showBestValueInfo = true
+                    }
+                }
 #endif
             }
             .task(id: stations.count) {
@@ -299,15 +316,15 @@ struct StationsView: View {
                             .listRowInsets(EdgeInsets(top: 4, leading: 16, bottom: 4, trailing: 16))
                         }
 
-                        Section("How Best Value works") {
-                            VStack(alignment: .leading, spacing: 10) {
-                                Text("Best Value compares each station with the closest one. It works out what you could save at the pump, then takes off the fuel used for the extra return journey.")
-                                Text("Your fill-up amount and MPG are used to show whether you could save overall.")
-                                Text("Results are marked “Approx.” until road distances are available.")
-                                    .foregroundStyle(.secondary)
+                        // The explanation is its own sheet now, opened from this
+                        // row. Gated exactly like the More info row and the Best
+                        // Value card itself: `isConfigured` is the same condition
+                        // `savingsForStation` uses, so the row appears and
+                        // disappears with the feature.
+                        if fuelSavingsSettings.isConfigured {
+                            Section {
+                                HowBestValueRow { showBestValueInfo = true }
                             }
-                            .font(.subheadline)
-                            .padding(.vertical, 4)
                         }
                     }
                     .navigationTitle("Key")
@@ -317,6 +334,8 @@ struct StationsView: View {
                             Button("Done") { showKey = false }
                         }
                     }
+                    // Nested sheet: the Key sheet stays behind the explanation.
+                    .sheet(isPresented: $showBestValueInfo) { HowBestValueSheet() }
                 }
                 .presentationDetents([.fraction(0.6)])
                 .presentationBackground(Color(UIColor.systemGroupedBackground))

FuelBoard/en.lproj/Localizable.strings

@@ -71,8 +71,8 @@
 "Name" = "Name";
 "Address" = "Address";
 "Distance" = "Distance";
-"Copied" = "Copied";
 "Copies the postcode" = "Copies the postcode";
+"Postcode copied" = "Postcode copied";
 "Address: %@" = "Address: %@";
 "Directions to %@" = "Directions to %@";
 "Opens Apple Maps with driving directions" = "Opens Apple Maps with driving directions";