diff --git a/src/components/interactives/NeighborSumAvoidance.tsx b/src/components/interactives/NeighborSumAvoidance.tsx
index 3689487..5e75c7a 100644
--- a/src/components/interactives/NeighborSumAvoidance.tsx
+++ b/src/components/interactives/NeighborSumAvoidance.tsx
@@ -41,6 +41,14 @@ const NeighborSumAvoidance = ({ shareUrl }: NeighborSumAvoidanceProps) => {
     };
   }, [isActive, isComplete]);
 
+  // Keep the pre-start arena in sync with the Numbers slider.
+  useEffect(() => {
+    if (!isActive) {
+      setSlots(Array(numberCount).fill(null));
+      setAvailableNumbers(Array.from({ length: numberCount }, (_, i) => i + 1));
+    }
+  }, [numberCount, isActive]);
+
   const isDivisible = (a: number, b: number) => {
     const sum = a + b;
     return sum % 3 === 0 || sum % 5 === 0 || sum % 7 === 0;
@@ -110,12 +118,13 @@ const NeighborSumAvoidance = ({ shareUrl }: NeighborSumAvoidanceProps) => {
   };
 
   const handleDragStart = (num: number, fromSlot: number | null) => {
+    if (!isActive) return;
     setDraggedNumber(num);
     setDraggedFrom(fromSlot);
   };
 
   const handleDrop = (toSlot: number) => {
-    if (draggedNumber === null) return;
+    if (!isActive || draggedNumber === null) return;
 
     if (mode === 'default') {
       // Default mode: place number in slot
@@ -140,6 +149,7 @@ const NeighborSumAvoidance = ({ shareUrl }: NeighborSumAvoidanceProps) => {
   };
 
   const handleSlotClick = (slotIndex: number) => {
+    if (!isActive) return;
     if (mode === 'default') {
       // Remove from slot in default mode
       if (slots[slotIndex] !== null) {
@@ -284,8 +294,9 @@ const NeighborSumAvoidance = ({ shareUrl }: NeighborSumAvoidanceProps) => {
           </CardDescription>
         </CardHeader>
         <CardContent className="space-y-6">
-          {!isActive ? (
-            <div className="space-y-6">
+          {/* Config controls — shown before start */}
+          {!isActive && (
+            <div className="space-y-4">
               <div className="flex items-center justify-center gap-6">
                 <div className="flex items-center gap-4">
                   <Label htmlFor="mode-switch">Default Mode</Label>
@@ -296,7 +307,7 @@ const NeighborSumAvoidance = ({ shareUrl }: NeighborSumAvoidanceProps) => {
                   />
                   <Label htmlFor="mode-switch">Guided Mode</Label>
                 </div>
-                
+
                 <div className="flex items-center gap-4 min-w-[200px]">
                   <Label htmlFor="number-count">Numbers: {numberCount}</Label>
                   <Slider
@@ -311,70 +322,79 @@ const NeighborSumAvoidance = ({ shareUrl }: NeighborSumAvoidanceProps) => {
                 </div>
               </div>
 
-              <div className="space-y-4 text-center">
-                <div className="text-sm text-muted-foreground space-y-2">
-                  {mode === 'default' ? (
-                    <>
-                      <p>Drag numbers from below into the circle slots.</p>
-                      <p>Adjacent numbers that sum to a multiple of 3, 5, or 7 will show a red arc.</p>
-                      <p>Click a filled slot to remove the number.</p>
-                    </>
-                  ) : (
-                    <>
-                      <p>Numbers are connected by edges if their sum is NOT divisible by 3, 5, or 7.</p>
-                      <p>Click two slots to swap their numbers and form a cycle on the circle's edge.</p>
-                    </>
-                  )}
-                </div>
-                <Button onClick={() => startGame(mode)} size="lg">
-                  Start {mode === 'default' ? 'Default' : 'Guided'} Mode
-                </Button>
+              <div className="text-sm text-muted-foreground space-y-2 text-center">
+                {mode === 'default' ? (
+                  <>
+                    <p>Drag numbers from below into the circle slots.</p>
+                    <p>Adjacent numbers that sum to a multiple of 3, 5, or 7 will show a red arc.</p>
+                    <p>Click a filled slot to remove the number.</p>
+                  </>
+                ) : (
+                  <>
+                    <p>Numbers are connected by edges if their sum is NOT divisible by 3, 5, or 7.</p>
+                    <p>Click two slots to swap their numbers and form a cycle on the circle's edge.</p>
+                  </>
+                )}
               </div>
             </div>
-          ) : (
-            <div className="space-y-6">
-              <div className="flex items-center justify-between">
-                <div className="flex items-center gap-2">
-                  <Timer className="w-4 h-4" />
-                  <span className="font-mono">{formatTime(time)}</span>
-                </div>
-                {mode === 'guided' && (
-                  <div className="text-sm text-muted-foreground">
-                    Swaps: {swaps}
-                  </div>
-                )}
-                <Button variant="outline" size="sm" onClick={restart}>
-                  <RotateCcw className="w-4 h-4 mr-2" />
-                  Restart
-                </Button>
+          )}
+
+          {/* Timer + controls — shown after start */}
+          {isActive && (
+            <div className="flex items-center justify-between">
+              <div className="flex items-center gap-2">
+                <Timer className="w-4 h-4" />
+                <span className="font-mono">{formatTime(time)}</span>
               </div>
-
-              {renderCircle()}
-
-              {mode === 'default' && availableNumbers.length > 0 && (
-                <div className="flex flex-wrap justify-center gap-4">
-                  {availableNumbers.map(num => (
-                    <div
-                      key={num}
-                      draggable
-                      onDragStart={() => handleDragStart(num, null)}
-                      className="w-12 h-12 rounded-full border-2 border-primary bg-background flex items-center justify-center text-lg font-bold cursor-move hover:scale-110 transition-transform"
-                    >
-                      {num}
-                    </div>
-                  ))}
+              {mode === 'guided' && (
+                <div className="text-sm text-muted-foreground">
+                  Swaps: {swaps}
                 </div>
               )}
+              <Button variant="outline" size="sm" onClick={restart}>
+                <RotateCcw className="w-4 h-4 mr-2" />
+                Restart
+              </Button>
+            </div>
+          )}
 
-              {isComplete && (
-                <div className="text-center space-y-4">
-                  <p className="text-lg font-semibold text-primary">
-                    🎉 Congratulations! You solved it in {formatTime(time)}
-                    {mode === 'guided' && ` with ${swaps} swaps`}!
-                  </p>
-                  <Button onClick={restart}>Play Again</Button>
+          {/* Arena — always visible */}
+          <div className={!isActive ? 'opacity-60 pointer-events-none' : ''}>
+            {renderCircle()}
+          </div>
+
+          {/* Start button — shown before start */}
+          {!isActive && (
+            <div className="text-center">
+              <Button onClick={() => startGame(mode)} size="lg">
+                Start {mode === 'default' ? 'Default' : 'Guided'} Mode
+              </Button>
+            </div>
+          )}
+
+          {/* Available numbers for default mode */}
+          {isActive && mode === 'default' && availableNumbers.length > 0 && (
+            <div className="flex flex-wrap justify-center gap-4">
+              {availableNumbers.map(num => (
+                <div
+                  key={num}
+                  draggable
+                  onDragStart={() => handleDragStart(num, null)}
+                  className="w-12 h-12 rounded-full border-2 border-primary bg-background flex items-center justify-center text-lg font-bold cursor-move hover:scale-110 transition-transform"
+                >
+                  {num}
                 </div>
-              )}
+              ))}
+            </div>
+          )}
+
+          {isComplete && (
+            <div className="text-center space-y-4">
+              <p className="text-lg font-semibold text-primary">
+                🎉 Congratulations! You solved it in {formatTime(time)}
+                {mode === 'guided' && ` with ${swaps} swaps`}!
+              </p>
+              <Button onClick={restart}>Play Again</Button>
             </div>
           )}
         </CardContent>
diff --git a/src/data/admin-data.json b/src/data/admin-data.json
index 4875a14..6c50267 100644
--- a/src/data/admin-data.json
+++ b/src/data/admin-data.json
@@ -333,8 +333,10 @@
       {
         "id": "474e8061-c7a2-49a2-ba85-a8c57814ea28",
         "text": "in both default and guided mode, show the arena. to begin with all interactions should be disabled, and enabled as soon as the user clicks the start button (this should set off th etimer too, as it does now).",
-        "done": false,
-        "refId": "T1"
+        "done": true,
+        "refId": "T1",
+        "remark": "Arena now renders pre-start (greyed with opacity-60 pointer-events-none). Drag/drop/click handlers short-circuit on !isActive as defense-in-depth. Start button still triggers startGame (kicks off timer + populates slots). Added a useEffect to resync slots/availableNumbers when the Numbers slider changes before start, so the pre-start arena always matches the chosen count.",
+        "doneDate": "2026-04-17"
       }
     ]
   }