diff --git a/dist/index.html b/dist/index.html
index 0cca11c..f8101ee 100644
--- a/dist/index.html
+++ b/dist/index.html
@@ -5,7 +5,7 @@
     <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>furniture-app</title>
-    <script type="module" crossorigin src="/assets/index-CEvVbPGt.js"></script>
+    <script type="module" crossorigin src="/assets/index-Be3LQNz7.js"></script>
     <link rel="stylesheet" crossorigin href="/assets/index-Gl7EQEpA.css">
   </head>
   <body>
diff --git a/src/App.tsx b/src/App.tsx
index 2dcc5dd..e8f20f2 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -5,6 +5,7 @@ import type { FurnitureConfig, FurniturePreset, LayoutState } from './types';
 import { runRandomSearch } from './optimization/randomSearch';
 import { optimizeWithNN } from './ai/nn';
 import { DEFAULT_PRESETS } from './furniture/presets';
+import { clampRectToRoom, clampStateToRoom } from './geometry/bounds';
 
 const initialState: LayoutState = {
   room: { width: 600, height: 400, gridSize: 10 },
@@ -13,20 +14,29 @@ const initialState: LayoutState = {
   presets: DEFAULT_PRESETS,
 };
 
-function makeFurniture(preset: FurniturePreset, index: number): FurnitureConfig {
+function makeFurniture(preset: FurniturePreset, index: number, room: LayoutState['room']): FurnitureConfig {
+  const spawn = clampRectToRoom(
+    {
+      x: 80 + (index % 5) * 60,
+      y: 80 + Math.floor(index / 5) * 60,
+      width: preset.shape.width,
+      height: preset.shape.height,
+    },
+    room,
+  );
   return {
     id: `${preset.id}_${Date.now()}_${index}`,
     name: `${preset.name} ${index + 1}`,
     type: preset.id,
     shape: {
       ...preset.shape,
-      x: 80 + (index % 5) * 60,
-      y: 80 + Math.floor(index / 5) * 60,
+      x: spawn.x,
+      y: spawn.y,
+      width: spawn.width,
+      height: spawn.height,
     },
     conditions: preset.conditions.map((c) => ({ ...c, params: { ...(c.params || {}) } })),
     color: preset.color,
-    lockedForOptimization: false,
-    placed: false,
   };
 }
 
@@ -49,7 +59,7 @@ function syncFurniture(state: LayoutState): LayoutState {
       furniture = furniture.filter((f) => !removeIds.has(f.id));
     } else if (existing.length < desired) {
       for (let i = existing.length; i < desired; i++) {
-        furniture.push(makeFurniture(preset, i));
+        furniture.push(makeFurniture(preset, i, state.room));
       }
     }
 
@@ -76,7 +86,7 @@ function App() {
   const [timeLeft, setTimeLeft] = useState(15);
 
   useEffect(() => {
-    setState((s) => syncFurniture(s));
+    setState((s) => clampStateToRoom(syncFurniture(s)));
   }, [state.presets]);
 
   useEffect(() => {
@@ -129,6 +139,7 @@ function App() {
             mode={mode}
             selectedId={selectedId}
             onSelect={setSelectedId}
+            showPaths={mode === 'optimize'}
           />
         </div>
       </div>
diff --git a/src/ai/nn.ts b/src/ai/nn.ts
index c76bc0c..4ba4220 100644
--- a/src/ai/nn.ts
+++ b/src/ai/nn.ts
@@ -1,5 +1,6 @@
 import type { LayoutEvaluation, LayoutState } from '../types';
 import { evaluateLayout } from '../layout/evaluator';
+import { clampRectToRoom } from '../geometry/bounds';
 
 export interface NNOptions {
   gridSize?: number;
@@ -55,10 +56,14 @@ export function optimizeWithNN(state: LayoutState, options: NNOptions = {}): { b
     }
     if (targetX < 0) targetX = 0;
     if (targetY < 0) targetY = 0;
-    if (targetX + f.shape.width > candidate.room.width) targetX = candidate.room.width - f.shape.width;
-    if (targetY + f.shape.height > candidate.room.height) targetY = candidate.room.height - f.shape.height;
-    f.shape.x = targetX;
-    f.shape.y = targetY;
+    const b = clampRectToRoom(
+      { x: targetX, y: targetY, width: f.shape.width, height: f.shape.height },
+      candidate.room,
+    );
+    f.shape.x = b.x;
+    f.shape.y = b.y;
+    f.shape.width = b.width;
+    f.shape.height = b.height;
   }
 
   const bestEval = evaluateLayout(candidate, options.gridSize || 10);
diff --git a/src/components/ControlPanel.tsx b/src/components/ControlPanel.tsx
index 7d0d7a7..06cfbae 100644
--- a/src/components/ControlPanel.tsx
+++ b/src/components/ControlPanel.tsx
@@ -1,6 +1,7 @@
 import { useEffect, useState } from 'react';
 import type { ConditionKind, Entrance, FurniturePreset, LayoutState, RoomConfig } from '../types';
 import { NumberField } from './NumberField';
+import { clampStateToRoom } from '../geometry/bounds';
 
 interface ControlPanelProps {
   state: LayoutState;
@@ -58,14 +59,16 @@ export function ControlPanel({
     if (selectedTypeId) setOpenId(selectedTypeId);
   }, [selectedTypeId]);
 
-  const setRoom = (room: Partial<RoomConfig>) => onStateChange({ ...state, room: { ...state.room, ...room } });
+  const setRoom = (room: Partial<RoomConfig>) =>
+    onStateChange(clampStateToRoom({ ...state, room: { ...state.room, ...room } }));
 
   const setEntrance = (entrance: Partial<Entrance>) => {
     if (!state.entrance) return;
-    onStateChange({ ...state, entrance: { ...state.entrance, ...entrance } });
+    onStateChange(clampStateToRoom({ ...state, entrance: { ...state.entrance, ...entrance } }));
   };
 
-  const placeEntrance = () => onStateChange({ ...state, entrance: { x: 20, y: 20, width: 20, height: 20 } });
+  const placeEntrance = () =>
+    onStateChange(clampStateToRoom({ ...state, entrance: { x: 20, y: 20, width: 20, height: 20 } }));
 
   const updateObject = (id: string, patch: Partial<FurniturePreset>) => {
     const presets = objects.map((p) => (p.id === id ? { ...p, ...patch } : p));
diff --git a/src/components/RoomCanvas.tsx b/src/components/RoomCanvas.tsx
index e02338f..fac571a 100644
--- a/src/components/RoomCanvas.tsx
+++ b/src/components/RoomCanvas.tsx
@@ -1,5 +1,7 @@
 import { useEffect, useRef, useState } from 'react';
 import type { LayoutState, Point } from '../types';
+import { computePaths } from '../pathfinding/paths';
+import { clampRectToRoom } from '../geometry/bounds';
 
 interface RoomCanvasProps {
   state: LayoutState;
@@ -7,6 +9,7 @@ interface RoomCanvasProps {
   mode: 'layout' | 'optimize';
   selectedId: string | null;
   onSelect: (id: string | null) => void;
+  showPaths?: boolean;
 }
 
 interface DragState {
@@ -16,14 +19,21 @@ interface DragState {
   resizing?: boolean;
 }
 
-export function RoomCanvas({ state, onStateChange, mode, selectedId, onSelect }: RoomCanvasProps) {
+export function RoomCanvas({ state, onStateChange, mode, selectedId, onSelect, showPaths }: RoomCanvasProps) {
   const canvasRef = useRef<HTMLCanvasElement>(null);
   const [drag, setDrag] = useState<DragState | null>(null);
   const [zoom] = useState(1);
+  const [phase, setPhase] = useState(0);
+
+  useEffect(() => {
+    if (!showPaths) return;
+    const t = setInterval(() => setPhase((p) => (p + 1) % 1000), 60);
+    return () => clearInterval(t);
+  }, [showPaths]);
 
   useEffect(() => {
     draw();
-  }, [state, selectedId, mode, zoom]);
+  }, [state, selectedId, mode, zoom, showPaths, phase]);
 
   const draw = () => {
     const canvas = canvasRef.current;
@@ -58,6 +68,32 @@ export function RoomCanvas({ state, onStateChange, mode, selectedId, onSelect }:
     ctx.lineWidth = 2;
     ctx.strokeRect(0, 0, state.room.width, state.room.height);
 
+    if (showPaths && state.entrance) {
+      const paths = computePaths(state, state.room.gridSize || 10);
+      ctx.save();
+      ctx.lineWidth = 2;
+      ctx.setLineDash([6, 6]);
+      ctx.lineDashOffset = -phase * 1.5;
+      for (const { path } of paths) {
+        if (path.length < 2) continue;
+        ctx.strokeStyle = 'rgba(79, 140, 255, 0.6)';
+        ctx.beginPath();
+        ctx.moveTo(path[0].x, path[0].y);
+        for (let i = 1; i < path.length; i++) {
+          ctx.lineTo(path[i].x, path[i].y);
+        }
+        ctx.stroke();
+        const end = path[path.length - 1];
+        ctx.setLineDash([]);
+        ctx.fillStyle = 'rgba(79, 140, 255, 0.9)';
+        ctx.beginPath();
+        ctx.arc(end.x, end.y, 3, 0, Math.PI * 2);
+        ctx.fill();
+        ctx.setLineDash([6, 6]);
+      }
+      ctx.restore();
+    }
+
     if (state.entrance) {
       const e = state.entrance;
       const w = e.width ?? 20;
@@ -166,25 +202,40 @@ export function RoomCanvas({ state, onStateChange, mode, selectedId, onSelect }:
     if (drag.id === '__entrance__' && state.entrance) {
       const en = state.entrance;
       if (drag.resizing) {
-        const newW = Math.max(10, pos.x - en.x);
-        const newH = Math.max(10, pos.y - en.y);
-        onStateChange({ ...state, entrance: { ...en, width: newW, height: newH } });
+        const b = clampRectToRoom(
+          { x: en.x, y: en.y, width: pos.x - en.x, height: pos.y - en.y },
+          state.room,
+          10,
+        );
+        onStateChange({ ...state, entrance: { ...en, ...b } });
       } else {
-        onStateChange({
-          ...state,
-          entrance: { ...en, x: pos.x - drag.offsetX, y: pos.y - drag.offsetY },
-        });
+        const b = clampRectToRoom(
+          { x: pos.x - drag.offsetX, y: pos.y - drag.offsetY, width: en.width ?? 20, height: en.height ?? 20 },
+          state.room,
+          10,
+        );
+        onStateChange({ ...state, entrance: { ...en, x: b.x, y: b.y } });
       }
       return;
     }
     const updated = state.furniture.map((f) => {
       if (f.id !== drag.id) return f;
+      const b = clampRectToRoom(
+        {
+          x: pos.x - drag.offsetX,
+          y: pos.y - drag.offsetY,
+          width: f.shape.width,
+          height: f.shape.height,
+        },
+        state.room,
+        10,
+      );
       return {
         ...f,
         shape: {
           ...f.shape,
-          x: pos.x - drag.offsetX,
-          y: pos.y - drag.offsetY,
+          x: b.x,
+          y: b.y,
         },
       };
     });
diff --git a/src/geometry/bounds.ts b/src/geometry/bounds.ts
new file mode 100644
index 0000000..6a70aaa
--- /dev/null
+++ b/src/geometry/bounds.ts
@@ -0,0 +1,41 @@
+import type { Entrance, FurnitureConfig, LayoutState, Rect, RoomConfig } from '../types';
+
+export interface Bounds {
+  x: number;
+  y: number;
+  width: number;
+  height: number;
+}
+
+export function clampRectToRoom(rect: Bounds, room: RoomConfig, minSize = 10): Bounds {
+  const width = Math.min(Math.max(minSize, rect.width), room.width);
+  const height = Math.min(Math.max(minSize, rect.height), room.height);
+  const x = Math.min(Math.max(0, rect.x), Math.max(0, room.width - width));
+  const y = Math.min(Math.max(0, rect.y), Math.max(0, room.height - height));
+  return { x, y, width, height };
+}
+
+export function clampStateToRoom(state: LayoutState): LayoutState {
+  const room = state.room;
+  const furniture: FurnitureConfig[] = state.furniture.map((f) => {
+    const b = clampRectToRoom(
+      { x: f.shape.x, y: f.shape.y, width: f.shape.width, height: f.shape.height },
+      room,
+    );
+    return { ...f, shape: { ...f.shape, ...b } };
+  });
+  let entrance: Entrance | null = state.entrance;
+  if (entrance) {
+    const ev = clampRectToRoom(
+      { x: entrance.x, y: entrance.y, width: entrance.width ?? 20, height: entrance.height ?? 20 },
+      room,
+      10,
+    );
+    entrance = { ...entrance, x: ev.x, y: ev.y, width: ev.width, height: ev.height };
+  }
+  return { ...state, furniture, entrance };
+}
+
+export function rectsOverlap(a: Rect, b: Rect): boolean {
+  return !(a.x + a.width <= b.x || b.x + b.width <= a.x || a.y + a.height <= b.y || b.y + b.height <= a.y);
+}
diff --git a/src/layout/evaluator.ts b/src/layout/evaluator.ts
index e1d25b6..fdec1a1 100644
--- a/src/layout/evaluator.ts
+++ b/src/layout/evaluator.ts
@@ -1,5 +1,5 @@
 import type { AccessibilityResult, FurnitureConfig, LayoutEvaluation, LayoutState, Point, Rect } from '../types';
-import { buildGrid } from '../pathfinding/grid';
+import { buildGrid, gridToWorld, nearestWalkable } from '../pathfinding/grid';
 import { aStar } from '../pathfinding/aStar';
 
 export function evaluateLayout(state: LayoutState, gridSize: number = 10): LayoutEvaluation {
@@ -19,12 +19,15 @@ export function evaluateLayout(state: LayoutState, gridSize: number = 10): Layou
   const conditionScores: Record<string, number> = {};
 
   const entrancePoint = state.entrance ? { x: state.entrance.x, y: state.entrance.y } : { x: 0, y: 0 };
+  const entranceCell = nearestWalkable(grid, entrancePoint, gridSize);
+  const entranceWorld = entranceCell ? gridToWorld(entranceCell.col, entranceCell.row, gridSize) : entrancePoint;
 
   for (const f of state.furniture) {
     const cx = f.shape.x + f.shape.width / 2;
     const cy = f.shape.y + f.shape.height / 2;
-    const target: Point = { x: cx, y: cy };
-    const path = aStar(entrancePoint, target, grid, gridSize);
+    const targetCell = nearestWalkable(grid, { x: cx, y: cy }, gridSize);
+    const target: Point = targetCell ? gridToWorld(targetCell.col, targetCell.row, gridSize) : { x: cx, y: cy };
+    const path = aStar(entranceWorld, target, grid, gridSize);
     if (path === null) {
       accessibility.push({ furnitureId: f.id, distanceFromEntrance: null, reachable: false, pathLength: null });
       penalty += 100;
diff --git a/src/optimization/randomSearch.ts b/src/optimization/randomSearch.ts
index b3d4f47..d8f3214 100644
--- a/src/optimization/randomSearch.ts
+++ b/src/optimization/randomSearch.ts
@@ -1,6 +1,7 @@
 import type { LayoutEvaluation, LayoutState } from '../types';
 import { evaluateLayout } from '../layout/evaluator';
 import { Furniture } from '../furniture/Furniture';
+import { clampRectToRoom } from '../geometry/bounds';
 
 export interface RandomSearchOptions {
   iterations: number;
@@ -20,12 +21,19 @@ export function runRandomSearch(
     const candidate = cloneState(bestState);
     for (const f of candidate.furniture) {
       if (f.lockedForOptimization) continue;
-      f.shape.x = Math.random() * (options.roomWidth - f.shape.width);
-      f.shape.y = Math.random() * (options.roomHeight - f.shape.height);
-      if (f.shape.x < 0) f.shape.x = 0;
-      if (f.shape.y < 0) f.shape.y = 0;
-      if (f.shape.x + f.shape.width > options.roomWidth) f.shape.x = options.roomWidth - f.shape.width;
-      if (f.shape.y + f.shape.height > options.roomHeight) f.shape.y = options.roomHeight - f.shape.height;
+      const b = clampRectToRoom(
+        {
+          x: Math.random() * Math.max(0, options.roomWidth - f.shape.width),
+          y: Math.random() * Math.max(0, options.roomHeight - f.shape.height),
+          width: f.shape.width,
+          height: f.shape.height,
+        },
+        { width: options.roomWidth, height: options.roomHeight },
+      );
+      f.shape.x = b.x;
+      f.shape.y = b.y;
+      f.shape.width = b.width;
+      f.shape.height = b.height;
     }
     const evalRes = evaluateLayout(candidate, options.gridSize || 10);
     if (evalRes.totalScore > bestEval.totalScore + 1e-9) {
diff --git a/src/pathfinding/grid.ts b/src/pathfinding/grid.ts
index 5111e6b..3721d2e 100644
--- a/src/pathfinding/grid.ts
+++ b/src/pathfinding/grid.ts
@@ -36,3 +36,31 @@ export function worldToGrid(p: Point, gridSize: number): { col: number; row: num
 export function gridToWorld(col: number, row: number, gridSize: number): Point {
   return { x: col * gridSize + gridSize / 2, y: row * gridSize + gridSize / 2 };
 }
+
+export function nearestWalkable(
+  grid: GridCell[][],
+  point: Point,
+  gridSize: number,
+): { col: number; row: number } | null {
+  const cols = grid[0]?.length ?? 0;
+  const rows = grid.length ?? 0;
+  const start = worldToGrid(point, gridSize);
+  const sc = Math.min(Math.max(start.col, 0), cols - 1);
+  const sr = Math.min(Math.max(start.row, 0), rows - 1);
+  if (grid[sr]?.[sc]?.walkable) return { col: sc, row: sr };
+
+  const maxRadius = Math.max(cols, rows);
+  for (let radius = 1; radius <= maxRadius; radius++) {
+    for (let dr = -radius; dr <= radius; dr++) {
+      for (let dc = -radius; dc <= radius; dc++) {
+        if (Math.abs(dr) !== radius && Math.abs(dc) !== radius) continue;
+        const c = sc + dc;
+        const r = sr + dr;
+        if (r < 0 || c < 0 || r >= rows || c >= cols) continue;
+        if (grid[r][c].walkable) return { col: c, row: r };
+      }
+    }
+  }
+  return null;
+}
+
diff --git a/src/pathfinding/paths.ts b/src/pathfinding/paths.ts
new file mode 100644
index 0000000..585c18f
--- /dev/null
+++ b/src/pathfinding/paths.ts
@@ -0,0 +1,32 @@
+import type { LayoutState, Point, Rect } from '../types';
+import { buildGrid, gridToWorld, nearestWalkable } from './grid';
+import { aStar } from './aStar';
+
+export interface ObjectPath {
+  furnitureId: string;
+  path: Point[];
+}
+
+export function computePaths(state: LayoutState, gridSize: number = 10): ObjectPath[] {
+  if (!state.entrance) return [];
+  const obstacles: Rect[] = state.furniture
+    .map((f) => ({ x: f.shape.x, y: f.shape.y, width: f.shape.width, height: f.shape.height }))
+    .filter((r) => r.width > 0 && r.height > 0);
+
+  const grid = buildGrid(state.room, obstacles, gridSize);
+  const entranceCell = nearestWalkable(grid, { x: state.entrance.x, y: state.entrance.y }, gridSize);
+  if (!entranceCell) return [];
+  const entranceWorld = gridToWorld(entranceCell.col, entranceCell.row, gridSize);
+
+  const paths: ObjectPath[] = [];
+  for (const f of state.furniture) {
+    const cx = f.shape.x + f.shape.width / 2;
+    const cy = f.shape.y + f.shape.height / 2;
+    const targetCell = nearestWalkable(grid, { x: cx, y: cy }, gridSize);
+    if (!targetCell) continue;
+    const target = gridToWorld(targetCell.col, targetCell.row, gridSize);
+    const path = aStar(entranceWorld, target, grid, gridSize);
+    if (path) paths.push({ furnitureId: f.id, path });
+  }
+  return paths;
+}