diff --git a/src/app/globals.css b/src/app/globals.css
index 36c28d12b..b230f566a 100644
--- a/src/app/globals.css
+++ b/src/app/globals.css
@@ -271,6 +271,10 @@
      the layered .edge-glass-header base and the unlayered max-width:639px
      guard so the values cannot drift apart. lg overrides to 1.5rem. */
   --header-edge-pad: 1rem;
+  /* Borderless app-shell/header height (the min-h-14 bar). Page shells fill the
+     viewport below it via calc(100dvh - var(--shell-header-h)); one token so the
+     header height and those page-fill floors cannot silently drift apart. */
+  --shell-header-h: 4rem;
   /* Keep in sync with mobile-composer-reserve.ts (phone dock clearance). */
   --phone-dock-hidden-pad: 0.75rem;
   --phone-dock-differentials-compare-clearance: 12.5rem;
diff --git a/src/components/clinical-dashboard/favourites-command-library-page.tsx b/src/components/clinical-dashboard/favourites-command-library-page.tsx
index 1b1a1b305..ad07922be 100644
--- a/src/components/clinical-dashboard/favourites-command-library-page.tsx
+++ b/src/components/clinical-dashboard/favourites-command-library-page.tsx
@@ -1074,7 +1074,7 @@ export function FavouritesCommandLibraryPage({ query = "", demoMode }: { query?:
     return (
       <main
         data-testid="favourites-hub"
-        className="min-h-0 overflow-x-clip bg-[color:var(--background)] pb-4 text-[color:var(--text)] sm:min-h-[calc(100dvh-4rem)] sm:pb-32 md:pb-0"
+        className="min-h-0 overflow-x-clip bg-[color:var(--background)] pb-4 text-[color:var(--text)] sm:min-h-[calc(100dvh-var(--shell-header-h))] sm:pb-32 md:pb-0"
       >
         <span data-testid="favourites-command-library" className="sr-only">
           Favourites command library
@@ -1128,14 +1128,14 @@ export function FavouritesCommandLibraryPage({ query = "", demoMode }: { query?:
   return (
     <main
       data-testid="favourites-hub"
-      className="min-h-0 overflow-x-clip bg-[color:var(--background)] pb-4 text-[color:var(--text)] sm:min-h-[calc(100dvh-4rem)] sm:pb-32 md:pb-0"
+      className="min-h-0 overflow-x-clip bg-[color:var(--background)] pb-4 text-[color:var(--text)] sm:min-h-[calc(100dvh-var(--shell-header-h))] sm:pb-32 md:pb-0"
     >
       <span data-testid="favourites-command-library" className="sr-only">
         Favourites command library
       </span>
       <div
         className={cn(
-          "grid min-h-0 min-w-0 overflow-x-clip sm:min-h-[calc(100dvh-4rem)]",
+          "grid min-h-0 min-w-0 overflow-x-clip sm:min-h-[calc(100dvh-var(--shell-header-h))]",
           navCollapsed ? "lg:grid-cols-[5.25rem_minmax(0,1fr)]" : "lg:grid-cols-[17.5rem_minmax(0,1fr)]",
           selectedItem &&
             (navCollapsed
diff --git a/src/components/clinical-dashboard/global-search-shell.tsx b/src/components/clinical-dashboard/global-search-shell.tsx
index 446994c56..5a77df1d6 100644
--- a/src/components/clinical-dashboard/global-search-shell.tsx
+++ b/src/components/clinical-dashboard/global-search-shell.tsx
@@ -753,7 +753,7 @@ function GlobalStandaloneSearchShellClient({
             // Phone: keep a block formatting scrollport (not a column flex). A
             // flex-1 child overflowed past a sibling spacer without extending
             // scrollHeight, which parked long pages under the visible dock.
-            "min-w-0 focus-visible:outline focus-visible:outline-2 focus-visible:outline-offset-[-2px] focus-visible:outline-[color:var(--focus)] max-sm:min-h-0 max-sm:flex-1 max-sm:overflow-x-hidden max-sm:overflow-y-auto max-sm:overscroll-contain max-sm:[-webkit-overflow-scrolling:touch] sm:min-h-[calc(100dvh-4rem)] sm:overflow-x-clip",
+            "min-w-0 focus-visible:outline focus-visible:outline-2 focus-visible:outline-offset-[-2px] focus-visible:outline-[color:var(--focus)] max-sm:min-h-0 max-sm:flex-1 max-sm:overflow-x-hidden max-sm:overflow-y-auto max-sm:overscroll-contain max-sm:[-webkit-overflow-scrolling:touch] sm:min-h-[calc(100dvh-var(--shell-header-h))] sm:overflow-x-clip",
             // sm+: static desktop clearance; use var(--safe-area-bottom) so tests
             // can simulate insets without depending on env() in Chromium.
             !reservesFloatingComposer
@@ -773,7 +773,7 @@ function GlobalStandaloneSearchShellClient({
           */}
           <div data-testid="mobile-composer-reserve-pad" className="max-sm:pb-[var(--mobile-composer-reserve)]">
             <ClientHydrationBoundary
-              fallback={<div className="min-h-[calc(100dvh-4rem)] overflow-x-hidden" aria-hidden />}
+              fallback={<div className="min-h-[calc(100dvh-var(--shell-header-h))] overflow-x-hidden" aria-hidden />}
             >
               <SearchCommandProvider value={searchCommandContextValue}>{children}</SearchCommandProvider>
             </ClientHydrationBoundary>
diff --git a/src/components/clinical-dashboard/medication-record-page.tsx b/src/components/clinical-dashboard/medication-record-page.tsx
index e159a07df..42d973756 100644
--- a/src/components/clinical-dashboard/medication-record-page.tsx
+++ b/src/components/clinical-dashboard/medication-record-page.tsx
@@ -496,7 +496,10 @@ export function MedicationRecordPage({
   const governance = data?.governance ?? (error ? undefined : fallbackGovernance);
 
   return (
-    <main className="min-h-[calc(100dvh-4rem)] text-[color:var(--text)]" data-testid={`medication-page-${slug}`}>
+    <main
+      className="min-h-[calc(100dvh-var(--shell-header-h))] text-[color:var(--text)]"
+      data-testid={`medication-page-${slug}`}
+    >
       <div className="mx-auto max-w-7xl px-3 pt-3 sm:px-6 lg:px-8">
         <Link
           href={`/?mode=prescribing&q=${encodeURIComponent(slug)}`}
diff --git a/src/components/differentials/differential-presentation-workflow-page.tsx b/src/components/differentials/differential-presentation-workflow-page.tsx
index a238bc937..72e1b5aaa 100644
--- a/src/components/differentials/differential-presentation-workflow-page.tsx
+++ b/src/components/differentials/differential-presentation-workflow-page.tsx
@@ -640,7 +640,7 @@ export function DifferentialPresentationWorkflowPage({
   return (
     <main
       data-testid="differential-presentation-page"
-      className="min-h-0 overflow-x-clip bg-[color:var(--background)] px-3 pb-[calc(6.25rem+env(safe-area-inset-bottom))] pt-4 text-[color:var(--text)] sm:min-h-[calc(100dvh-4rem)] sm:px-5 md:pb-8 xl:px-7 xl:pt-6"
+      className="min-h-0 overflow-x-clip bg-[color:var(--background)] px-3 pb-[calc(6.25rem+env(safe-area-inset-bottom))] pt-4 text-[color:var(--text)] sm:min-h-[calc(100dvh-var(--shell-header-h))] sm:px-5 md:pb-8 xl:px-7 xl:pt-6"
     >
       <div className="mx-auto grid w-full max-w-[94rem] gap-5 xl:grid-cols-[minmax(0,1fr)_23.5rem]">
         <div className="min-w-0">
diff --git a/src/components/differentials/differential-stream-page.tsx b/src/components/differentials/differential-stream-page.tsx
index 3aba60696..eba178f6e 100644
--- a/src/components/differentials/differential-stream-page.tsx
+++ b/src/components/differentials/differential-stream-page.tsx
@@ -40,7 +40,7 @@ const streamCopy: Record<
 export function DifferentialStreamPage({ stream, query = "" }: DifferentialStreamPageProps) {
   const copy = streamCopy[stream];
   return (
-    <main className="min-h-[calc(100dvh-4rem)] bg-[color:var(--background)] px-4 py-10 text-[color:var(--text)] sm:px-6 lg:px-8">
+    <main className="min-h-[calc(100dvh-var(--shell-header-h))] bg-[color:var(--background)] px-4 py-10 text-[color:var(--text)] sm:px-6 lg:px-8">
       <div className="mx-auto grid w-full max-w-6xl gap-6">
         <section className="rounded-lg border border-[color:var(--border-lux)] bg-[color:var(--surface-lux)] p-4 shadow-[var(--shadow-soft)] sm:p-6">
           <p className="text-xs font-bold uppercase tracking-[0.08em] text-[color:var(--clinical-accent)]">
diff --git a/src/components/forms/form-detail-page.tsx b/src/components/forms/form-detail-page.tsx
index 64051ca74..36004c05d 100644
--- a/src/components/forms/form-detail-page.tsx
+++ b/src/components/forms/form-detail-page.tsx
@@ -559,7 +559,7 @@ export function FormDetailPage({ form }: { form: FormRecord }) {
   return (
     <main
       data-testid="form-detail-page"
-      className="max-sm:min-h-0 bg-[color:var(--background)] px-3 pb-4 pt-4 text-[color:var(--text)] sm:min-h-[calc(100dvh-4rem)] sm:px-5 sm:pb-10 sm:pt-6 lg:px-8"
+      className="max-sm:min-h-0 bg-[color:var(--background)] px-3 pb-4 pt-4 text-[color:var(--text)] sm:min-h-[calc(100dvh-var(--shell-header-h))] sm:px-5 sm:pb-10 sm:pt-6 lg:px-8"
     >
       <div className={pageContainer}>
         {notice ? (
diff --git a/src/components/formulation/formulation-ui.tsx b/src/components/formulation/formulation-ui.tsx
index becae60a0..c80523e4e 100644
--- a/src/components/formulation/formulation-ui.tsx
+++ b/src/components/formulation/formulation-ui.tsx
@@ -13,7 +13,7 @@ export function FormulationPageShell({ children, className }: { children: ReactN
       className={cn(
         // Phone shell owns dock clearance; avoid 100dvh min-height overflowing the
         // inset scrollport the way service/form detail pages used to.
-        "max-sm:min-h-0 bg-[color:var(--background)] px-3 py-4 pb-4 text-[color:var(--text)] sm:min-h-[calc(100dvh-4rem)] sm:px-5 sm:py-6 sm:pb-10 lg:px-7",
+        "max-sm:min-h-0 bg-[color:var(--background)] px-3 py-4 pb-4 text-[color:var(--text)] sm:min-h-[calc(100dvh-var(--shell-header-h))] sm:px-5 sm:py-6 sm:pb-10 lg:px-7",
         className,
       )}
     >
diff --git a/src/components/mode-home-page-skeleton.tsx b/src/components/mode-home-page-skeleton.tsx
index 3280ca630..d15b2792e 100644
--- a/src/components/mode-home-page-skeleton.tsx
+++ b/src/components/mode-home-page-skeleton.tsx
@@ -32,7 +32,7 @@ export function ModeHomePageSkeleton() {
 
 export function ModeHomeRouteLoading() {
   return (
-    <div className="grid min-h-[calc(100dvh-13.5rem-env(safe-area-inset-top)-env(safe-area-inset-bottom))] items-center justify-items-center bg-[color:var(--background)] sm:min-h-[calc(100dvh-4rem)]">
+    <div className="grid min-h-[calc(100dvh-13.5rem-env(safe-area-inset-top)-env(safe-area-inset-bottom))] items-center justify-items-center bg-[color:var(--background)] sm:min-h-[calc(100dvh-var(--shell-header-h))]">
       <ModeHomePageSkeleton />
     </div>
   );
@@ -59,7 +59,11 @@ export function DocumentSearchPageSkeleton() {
 
 export function DocumentViewerPageSkeleton() {
   return (
-    <div className="flex h-[calc(100dvh-4rem)] flex-col gap-4 px-4 py-4" role="status" aria-label="Loading document">
+    <div
+      className="flex h-[calc(100dvh-var(--shell-header-h))] flex-col gap-4 px-4 py-4"
+      role="status"
+      aria-label="Loading document"
+    >
       <SkeletonBlock className="h-10 w-full max-w-lg" />
       <SkeletonBlock className="min-h-0 flex-1 rounded-lg" />
       <span className="sr-only">Loading document</span>
diff --git a/src/components/mode-home-template.tsx b/src/components/mode-home-template.tsx
index 4fc9af56a..34c55dc7e 100644
--- a/src/components/mode-home-template.tsx
+++ b/src/components/mode-home-template.tsx
@@ -146,7 +146,7 @@ export function ModeHomeMain({
     <main
       data-testid={testId}
       className={cn(
-        "flex min-h-0 w-full flex-1 flex-col items-center bg-[color:var(--background)] px-0 pb-4 text-[color:var(--text)] sm:min-h-[calc(100dvh-4rem)] sm:px-6 sm:pb-[clamp(1.75rem,5vh,3.25rem)] lg:px-8",
+        "flex min-h-0 w-full flex-1 flex-col items-center bg-[color:var(--background)] px-0 pb-4 text-[color:var(--text)] sm:min-h-[calc(100dvh-var(--shell-header-h))] sm:px-6 sm:pb-[clamp(1.75rem,5vh,3.25rem)] lg:px-8",
         withoutJustifyUtilities(className),
         MODE_HOME_MAIN_ALIGN_CLASS[contentAlign],
       )}
diff --git a/src/components/services/service-detail-page.tsx b/src/components/services/service-detail-page.tsx
index 4756992ca..1ac66e5d9 100644
--- a/src/components/services/service-detail-page.tsx
+++ b/src/components/services/service-detail-page.tsx
@@ -508,7 +508,7 @@ export function ServiceDetailPage({ service }: { service: ServiceRecord }) {
       // Phone shell already owns dock clearance via --mobile-composer-reserve.
       // A 100dvh min-height here overflows the inset scrollport and parks the
       // page footer under the visible dock even when the shell pad is correct.
-      className="max-sm:min-h-0 max-sm:shrink-0 bg-[color:var(--background)] px-3 py-4 pb-4 text-[color:var(--text)] sm:min-h-[calc(100dvh-4rem)] sm:px-5 sm:py-6 sm:pb-10 lg:px-8"
+      className="max-sm:min-h-0 max-sm:shrink-0 bg-[color:var(--background)] px-3 py-4 pb-4 text-[color:var(--text)] sm:min-h-[calc(100dvh-var(--shell-header-h))] sm:px-5 sm:py-6 sm:pb-10 lg:px-8"
     >
       <div className={pageContainer}>
         {notice ? (
diff --git a/src/components/specifiers/specifier-ui.tsx b/src/components/specifiers/specifier-ui.tsx
index 09ab25f8f..101d842d8 100644
--- a/src/components/specifiers/specifier-ui.tsx
+++ b/src/components/specifiers/specifier-ui.tsx
@@ -26,7 +26,7 @@ export function SpecifierPageShell({ children, className }: { children: ReactNod
       className={cn(
         // Phone shell owns dock clearance; avoid 100dvh min-height overflowing the
         // inset scrollport the way service/form detail pages used to.
-        "max-sm:min-h-0 bg-[color:var(--background)] px-3 py-4 pb-4 text-[color:var(--text)] sm:min-h-[calc(100dvh-4rem)] sm:px-5 sm:py-6 sm:pb-10 lg:px-7",
+        "max-sm:min-h-0 bg-[color:var(--background)] px-3 py-4 pb-4 text-[color:var(--text)] sm:min-h-[calc(100dvh-var(--shell-header-h))] sm:px-5 sm:py-6 sm:pb-10 lg:px-7",
         className,
       )}
     >
diff --git a/src/components/therapy-compass/therapy-compass.css b/src/components/therapy-compass/therapy-compass.css
index ba98ea575..64ac06016 100644
--- a/src/components/therapy-compass/therapy-compass.css
+++ b/src/components/therapy-compass/therapy-compass.css
@@ -1,5 +1,5 @@
 .tc-root {
-  min-height: calc(100dvh - 4rem);
+  min-height: calc(100dvh - var(--shell-header-h));
   background: var(--surface-chrome);
   color: var(--text);
 }
@@ -1293,7 +1293,7 @@
   padding: 32px 40px 40px;
 }
 .tc-root .tc-workspace-006 {
-  min-height: calc(100dvh - 4rem);
+  min-height: calc(100dvh - var(--shell-header-h));
   background: var(--surface-chrome);
   color: var(--text);
 }
diff --git a/src/components/ui-primitives.tsx b/src/components/ui-primitives.tsx
index 79591013f..6bb92c20e 100644
--- a/src/components/ui-primitives.tsx
+++ b/src/components/ui-primitives.tsx
@@ -132,7 +132,7 @@ export const searchPageCanvas = "bg-[color:var(--background)] text-[color:var(--
 // --mobile-composer-reserve so it can collapse when the dock hides. Do not bake
 // a second dock-sized safe-area pad into page shells.
 export const searchPageShell =
-  "min-h-[calc(100dvh-4rem)] overflow-x-hidden px-3 py-3 pb-4 sm:px-5 sm:py-5 sm:pb-8 lg:px-6";
+  "min-h-[calc(100dvh-var(--shell-header-h))] overflow-x-hidden px-3 py-3 pb-4 sm:px-5 sm:py-5 sm:pb-8 lg:px-6";
 export const searchPageContainer = "mx-auto w-full max-w-[1500px]";
 // Canonical content-page width. Detail pages (service / form / differential),
 // medication record + prescribing workspace, and the forms results view converge
diff --git a/tests/mobile-interaction-regressions.test.ts b/tests/mobile-interaction-regressions.test.ts
index 1fde939a4..d2001e93f 100644
--- a/tests/mobile-interaction-regressions.test.ts
+++ b/tests/mobile-interaction-regressions.test.ts
@@ -27,12 +27,14 @@ describe("mobile interaction regressions", () => {
     const differentialsHomeSource = source("src/components/clinical-dashboard/differentials-home.tsx");
 
     expect(presentationSource).toMatch(
-      /data-testid="differential-presentation-page"\s+className="[^"]*min-h-0[^"]*overflow-x-clip[^"]*sm:min-h-\[calc\(100dvh-4rem\)\]/,
+      /data-testid="differential-presentation-page"\s+className="[^"]*min-h-0[^"]*overflow-x-clip[^"]*sm:min-h-\[calc\(100dvh-var\(--shell-header-h\)\)\]/,
     );
     expect(favouritesSource).toMatch(
-      /data-testid="favourites-hub"\s+className="[^"]*min-h-0[^"]*overflow-x-clip[^"]*sm:min-h-\[calc\(100dvh-4rem\)\]/,
+      /data-testid="favourites-hub"\s+className="[^"]*min-h-0[^"]*overflow-x-clip[^"]*sm:min-h-\[calc\(100dvh-var\(--shell-header-h\)\)\]/,
+    );
+    expect(favouritesSource).toContain(
+      '"grid min-h-0 min-w-0 overflow-x-clip sm:min-h-[calc(100dvh-var(--shell-header-h))]"',
     );
-    expect(favouritesSource).toContain('"grid min-h-0 min-w-0 overflow-x-clip sm:min-h-[calc(100dvh-4rem)]"');
     // overflow-x-hidden would force overflow-y:auto and nest a scrollport under #main-content.
     expect(differentialsHomeSource).toMatch(
       /data-testid="differentials-search-results"[\s\S]*?className="[^"]*overflow-x-clip[^"]*"/,