Batch 2: List-map layout rework — 420px fixed column, sticky headers

- WizardLayout ListMapLayout: 420px fixed left column (D-B), flex:1
  right panel, back link rendered inside left panel instead of above
  the split (eliminates gap above map)
- LAYOUT_MAP type updated to accept backLink prop for list-map variant
- ProvidersStep: heading + search + filters wrapped in sticky Box
  that pins at top of scrollable left panel while card list scrolls
- VenueStep: same sticky header treatment, heading moved inside form
  for consistent wrapper structure

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/components/pages/ProvidersStep/ProvidersStep.tsx

@@ -146,7 +146,18 @@ export const ProvidersStep: React.FC<ProvidersStepProps> = ({
         )
       }
     >
-      {/* Header */}
+      {/* Sticky header — stays pinned while card list scrolls */}
+      <Box
+        sx={{
+          position: 'sticky',
+          top: 0,
+          zIndex: 1,
+          bgcolor: 'background.default',
+          pb: 1,
+          mx: -3,
+          px: 3,
+        }}
+      >
         <Typography variant="display3" component="h1" sx={{ mb: 0.5 }} tabIndex={-1}>
           Choose a funeral provider
         </Typography>
@@ -185,11 +196,12 @@ export const ProvidersStep: React.FC<ProvidersStepProps> = ({
         <Typography
           variant="caption"
           color="text.secondary"
-        sx={{ mb: 2, display: 'block' }}
+          sx={{ mb: 0, display: 'block' }}
           aria-live="polite"
         >
           {providers.length} provider{providers.length !== 1 ? 's' : ''} found
         </Typography>
+      </Box>
 
       {/* Error message */}
       {error && (

src/components/pages/VenueStep/VenueStep.tsx

@@ -193,7 +193,27 @@ export const VenueStep: React.FC<VenueStepProps> = ({
         )
       }
     >
-      {/* Page heading */}
+      <Box
+        component="form"
+        noValidate
+        aria-busy={loading}
+        onSubmit={(e: React.FormEvent) => {
+          e.preventDefault();
+          if (!loading) onContinue();
+        }}
+      >
+        {/* Sticky header — stays pinned while card list scrolls */}
+        <Box
+          sx={{
+            position: 'sticky',
+            top: 0,
+            zIndex: 1,
+            bgcolor: 'background.default',
+            pb: 1,
+            mx: -3,
+            px: 3,
+          }}
+        >
           <Typography variant="display3" component="h1" sx={{ mb: 0.5 }} tabIndex={-1}>
             Where would you like the service?
           </Typography>
@@ -204,17 +224,8 @@ export const VenueStep: React.FC<VenueStepProps> = ({
               : 'Choose a venue for the funeral service. You can filter by location, features, and religion.'}
           </Typography>
 
-      <Box
-        component="form"
-        noValidate
-        aria-busy={loading}
-        onSubmit={(e: React.FormEvent) => {
-          e.preventDefault();
-          if (!loading) onContinue();
-        }}
-      >
           {/* ─── Search + Filters ─── */}
-        <Box sx={{ mb: 3 }}>
+          <Box sx={{ mb: 2 }}>
             <TextField
               placeholder="Search a town or suburb..."
               value={values.search}
@@ -243,10 +254,11 @@ export const VenueStep: React.FC<VenueStepProps> = ({
           </Box>
 
           {/* ─── Results count ─── */}
-        <Typography variant="body2" color="text.secondary" sx={{ mb: 2 }} aria-live="polite">
+          <Typography variant="body2" color="text.secondary" sx={{ mb: 0 }} aria-live="polite">
             Found {venues.length} venue{venues.length !== 1 ? 's' : ''}
             {locationName ? ` near ${locationName}` : ''}
           </Typography>
+        </Box>
 
         {/* ─── Venue card grid ─── */}
         <Box

src/components/templates/WizardLayout/WizardLayout.tsx

@@ -142,11 +142,12 @@ const CenteredFormLayout: React.FC<{ children: React.ReactNode }> = ({ children
   </Container>
 );
 
-/** List + Map: ~40% scrollable list (left) / ~60% map (right) */
+/** List + Map: 420px fixed scrollable list (left) / flex map (right) — D-B */
 const ListMapLayout: React.FC<{
   children: React.ReactNode;
   secondaryPanel?: React.ReactNode;
-}> = ({ children, secondaryPanel }) => (
+  backLink?: React.ReactNode;
+}> = ({ children, secondaryPanel, backLink }) => (
   <Box
     sx={{
       display: 'flex',
@@ -156,18 +157,20 @@ const ListMapLayout: React.FC<{
   >
     <Box
       sx={{
-        width: { xs: '100%', md: '40%' },
+        width: { xs: '100%', md: 420 },
+        flexShrink: 0,
         overflowY: 'auto',
         px: { xs: 2, md: 3 },
         py: 3,
       }}
     >
+      {backLink}
       {children}
     </Box>
     <Box
       sx={{
-        display: { xs: 'none', md: 'block' },
+        display: { xs: 'none', md: 'flex' },
-        width: '60%',
+        flex: 1,
         position: 'relative',
       }}
     >
@@ -246,7 +249,11 @@ const DetailTogglesLayout: React.FC<{
 
 const LAYOUT_MAP: Record<
   WizardLayoutVariant,
-  React.FC<{ children: React.ReactNode; secondaryPanel?: React.ReactNode }>
+  React.FC<{
+    children: React.ReactNode;
+    secondaryPanel?: React.ReactNode;
+    backLink?: React.ReactNode;
+  }>
 > = {
   'centered-form': CenteredFormLayout,
   'list-map': ListMapLayout,
@@ -313,8 +320,8 @@ export const WizardLayout = React.forwardRef<HTMLDivElement, WizardLayoutProps>(
         {/* Stepper + running total bar (grid-sidebar, detail-toggles only) */}
         {showStepper && <StepperBar stepper={progressStepper} total={runningTotal} />}
 
-        {/* Back link — inside a container for consistent alignment */}
+        {/* Back link — inside left panel for list-map, above content for others */}
-        {showBackLink && (
+        {showBackLink && variant !== 'list-map' && (
           <Container
             maxWidth={variant === 'centered-form' ? 'sm' : 'lg'}
             sx={{ pt: 2, px: { xs: 4, md: 3 } }}
@@ -325,7 +332,16 @@ export const WizardLayout = React.forwardRef<HTMLDivElement, WizardLayoutProps>(
 
         {/* Main content area */}
         <Box component="main" sx={{ display: 'flex', flexDirection: 'column', flex: 1 }}>
-          <LayoutComponent secondaryPanel={secondaryPanel}>{children}</LayoutComponent>
+          <LayoutComponent
+            secondaryPanel={secondaryPanel}
+            backLink={
+              showBackLink && variant === 'list-map' ? (
+                <BackLink label={backLabel} onClick={onBack} />
+              ) : undefined
+            }
+          >
+            {children}
+          </LayoutComponent>
         </Box>
 
         {/* Sticky help bar */}