diff --git a/.gitignore b/.gitignore
index 3c3629e..08b2553 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1 @@
-node_modules
+node_modules
diff --git a/src/components/DrawingCanvas.js b/src/components/DrawingCanvas.js
index 9e8dcd5..3efce3d 100644
--- a/src/components/DrawingCanvas.js
+++ b/src/components/DrawingCanvas.js
@@ -1,236 +1,213 @@
-import React, { useRef, useState, useEffect } from 'react';
+import React, { useState, useEffect, useRef, useCallback } from 'react';
 import { ChromePicker } from 'react-color';
 
-// Drawing utilities
-const drawLine = (ctx, x1, y1, x2, y2, color, thickness) => {
-  ctx.beginPath();
-  ctx.moveTo(x1, y1);
-  ctx.lineTo(x2, y2);
-  ctx.strokeStyle = color || '#000000';
-  ctx.lineWidth = thickness || 2;
-  ctx.lineCap = 'round';
-  ctx.stroke();
-};
-
+// Update drawShape to handle pencil strokes
 const drawShape = (ctx, shape) => {
   ctx.beginPath();
-  ctx.strokeStyle = shape.color || '#000000';
-  ctx.lineWidth = shape.thickness || 2;
-  ctx.lineCap = 'round';
-
+  ctx.strokeStyle = shape.color;
+  ctx.lineWidth = shape.thickness;
   if (shape.type === 'rectangle') {
-    ctx.rect(shape.x || 0, shape.y || 0, shape.width || 0, shape.height || 0);
+    ctx.rect(shape.x, shape.y, shape.width, shape.height);
+    ctx.stroke();
   } else if (shape.type === 'circle') {
-    ctx.arc(shape.x || 0, shape.y || 0, shape.radius || 0, 0, Math.PI * 2);
+    ctx.arc(shape.x, shape.y, shape.radius, 0, Math.PI * 2);
+    ctx.stroke();
+  } else if (shape.type === 'pencil') {
+    if (shape.points.length < 2) return;
+    ctx.moveTo(shape.points[0].x, shape.points[0].y);
+    for (let i = 1; i < shape.points.length; i++) {
+      ctx.lineTo(shape.points[i].x, shape.points[i].y);
+    }
+    ctx.stroke();
   }
-
-  ctx.stroke();
 };
 
 const DrawingCanvas = () => {
   const canvasRef = useRef(null);
   const [isDrawing, setIsDrawing] = useState(false);
+  const [lastPosition, setLastPosition] = useState(null);
+  const [history, setHistory] = useState([]);
+  const [undoHistory, setUndoHistory] = useState([]);
+  const [shapes, setShapes] = useState([]);
   const [currentTool, setCurrentTool] = useState('pencil');
   const [color, setColor] = useState('#000000');
   const [thickness, setThickness] = useState(2);
-  const [history, setHistory] = useState([]);
-  const [shapes, setShapes] = useState([]);
-  const [lastPosition, setLastPosition] = useState(null);
-  const [undoHistory, setUndoHistory] = useState([]);
 
+  // Resize canvas on window resize
   useEffect(() => {
+    const resizeCanvas = () => {
+      const canvas = canvasRef.current;
+      if (!canvas) return;
+      canvas.width = window.innerWidth - 300;
+      canvas.height = window.innerHeight - 100;
+      redraw();
+    };
+    window.addEventListener('resize', resizeCanvas);
+    resizeCanvas();
+    return () => window.removeEventListener('resize', resizeCanvas);
+    // eslint-disable-next-line
+  }, []);
+
+  // Redraw everything
+  const redraw = useCallback(() => {
     const canvas = canvasRef.current;
     if (!canvas) return;
-    
     const ctx = canvas.getContext('2d');
-    if (!ctx) return;
-
-    // Set initial canvas size
-    canvas.width = window.innerWidth - 300;
-    canvas.height = window.innerHeight - 100;
-
-    // Clear canvas first
     ctx.clearRect(0, 0, canvas.width, canvas.height);
-
-    // Draw all shapes
-    shapes.forEach((shape) => {
-      drawShape(ctx, shape);
-    });
-
-    // Draw all pencil strokes from history
-    history.forEach((action) => {
-      if (action.type === 'draw') {
-        drawLine(ctx, action.x1, action.y1, action.x2, action.y2, action.color, action.thickness);
+    shapes.forEach(shape => drawShape(ctx, shape));
+    history.forEach(action => {
+      if (action.type === 'stroke') {
+        ctx.putImageData(action.imageData, 0, 0);
       }
     });
+  }, [shapes, history]);
 
-    // Force a re-render to ensure everything is drawn
-    if (canvas) {
-      canvas.style.display = 'none';
-      // Trigger reflow by forcing layout calculation
-      const width = canvas.offsetWidth;
-      canvas.style.display = 'block';
-    }
-  }, [history, shapes]);
+  useEffect(() => {
+    redraw();
+  }, [shapes, history, redraw]);
 
-  const handleMouseDown = (e) => {
-    setIsDrawing(true);
+  // Get mouse or touch position
+  const getPos = (e) => {
     const canvas = canvasRef.current;
     const rect = canvas.getBoundingClientRect();
-    const x = e.clientX - rect.left;
-    const y = e.clientY - rect.top;
+    if (e.touches) {
+      return {
+        x: e.touches[0].clientX - rect.left,
+        y: e.touches[0].clientY - rect.top,
+      };
+    }
+    return {
+      x: e.clientX - rect.left,
+      y: e.clientY - rect.top,
+    };
+  };
+
+  const handlePointerDown = (e) => {
+    e.preventDefault();
+    const { x, y } = getPos(e);
+    setIsDrawing(true);
 
     if (currentTool === 'pencil') {
-      setLastPosition({ x, y });
-    } else if (currentTool === 'rectangle') {
-      setShapes([...shapes, {
-        type: 'rectangle',
+      // Start a new pencil stroke
+      setShapes(prev => [
+        ...prev,
+        {
+          type: 'pencil',
+          color,
+          thickness,
+          points: [{ x, y }]
+        }
+      ]);
+    } else if (currentTool === 'rectangle' || currentTool === 'circle') {
+      const newShape = {
+        type: currentTool,
         x,
         y,
         width: 0,
         height: 0,
-        color,
-        thickness
-      }]);
-    } else if (currentTool === 'circle') {
-      setShapes([...shapes, {
-        type: 'circle',
-        x,
-        y,
         radius: 0,
         color,
-        thickness
-      }]);
+        thickness,
+      };
+      setShapes(prev => [...prev, newShape]);
     }
   };
 
-  const handleMouseMove = (e) => {
+  const handlePointerMove = (e) => {
     if (!isDrawing) return;
-    
-    const canvas = canvasRef.current;
-    const rect = canvas.getBoundingClientRect();
-    const x = e.clientX - rect.left;
-    const y = e.clientY - rect.top;
+    const { x, y } = getPos(e);
 
     if (currentTool === 'pencil') {
-      const lastPos = lastPosition;
-      
-      if (lastPos) {
-        // Don't draw immediately, just update history
-        setHistory(prevHistory => [...prevHistory, {
-          type: 'draw',
-          x1: lastPos.x,
-          y1: lastPos.y,
-          x2: x,
-          y2: y,
-          color,
-          thickness
-        }]);
-      }
-
-      // Update last position
-      setLastPosition({ x, y });
-    } else if (currentTool === 'rectangle' || currentTool === 'circle') {
-      const updatedShapes = shapes.map((shape, index) => {
-        if (index === shapes.length - 1) {
-          // Update the shape dimensions
-          if (currentTool === 'rectangle') {
-            const width = Math.abs(x - shape.x);
-            const height = Math.abs(y - shape.y);
-            return { ...shape, width, height };
-          } else if (currentTool === 'circle') {
-            const radius = Math.sqrt(Math.pow(x - shape.x, 2) + Math.pow(y - shape.y, 2));
-            return { ...shape, radius };
-          }
-        }
-        return shape;
+      setShapes(prev => {
+        if (prev.length === 0) return prev;
+        const updated = [...prev];
+        const lastStroke = { ...updated[updated.length - 1] };
+        lastStroke.points = [...lastStroke.points, { x, y }];
+        updated[updated.length - 1] = lastStroke;
+        return updated;
+      });
+    } else if (currentTool === 'rectangle' || currentTool === 'circle') {
+      setShapes(prev => {
+        if (prev.length === 0) return prev;
+        const updated = [...prev];
+        const shape = { ...updated[updated.length - 1] };
+        if (currentTool === 'rectangle') {
+          shape.width = x - shape.x;
+          shape.height = y - shape.y;
+        } else if (currentTool === 'circle') {
+          shape.radius = Math.sqrt(Math.pow(x - shape.x, 2) + Math.pow(y - shape.y, 2));
+        }
+        updated[updated.length - 1] = shape;
+        return updated;
       });
-      
-      // Add shape to history when it's created
-      if (updatedShapes.length > 0) {
-        const lastShape = updatedShapes[updatedShapes.length - 1];
-        setHistory(prevHistory => [...prevHistory, {
-          type: 'shape',
-          shape: lastShape
-        }]);
-      }
-      
-      setShapes(updatedShapes);
     }
   };
 
-  const handleMouseUp = () => {
+  const handlePointerUp = () => {
     setIsDrawing(false);
     setLastPosition(null);
+    // Save a snapshot of shapes for undo/redo
+    setHistory(prev => [...prev, shapes]);
     setUndoHistory([]);
   };
 
+  // Undo: restore the previous snapshot
   const handleUndo = () => {
-    if (history.length > 0) {
-      // Clear the last action from history
-      setHistory(prevHistory => prevHistory.slice(0, -1));
-      
-      // Add it to undo history
-      setUndoHistory(prev => [...prev, history[history.length - 1]]);
-      
-      // Clear the last shape if it exists
-      if (shapes.length > 0) {
-        setShapes(prevShapes => prevShapes.slice(0, -1));
-      }
-    }
+    if (history.length === 0) return;
+    setUndoHistory(prev => [...prev, shapes]);
+    const prevShapes = history[history.length - 1];
+    setShapes(prevShapes);
+    setHistory(prev => prev.slice(0, -1));
   };
 
+  // Redo: restore the next snapshot
   const handleRedo = () => {
-    if (undoHistory.length > 0) {
-      const lastUndo = undoHistory[undoHistory.length - 1];
-      
-      // Add the action back to history
-      setHistory(prevHistory => [...prevHistory, lastUndo]);
-      
-      // Remove it from undo history
-      setUndoHistory(prev => prev.slice(0, -1));
-      
-      // Add the shape back if it exists
-      if (lastUndo.type === 'shape') {
-        setShapes(prevShapes => [...prevShapes, lastUndo.shape]);
-      }
-    }
+    if (undoHistory.length === 0) return;
+    setHistory(prev => [...prev, shapes]);
+    const nextShapes = undoHistory[undoHistory.length - 1];
+    setShapes(nextShapes);
+    setUndoHistory(prev => prev.slice(0, -1));
   };
 
+  // Touch events for mobile
+  useEffect(() => {
+    const canvas = canvasRef.current;
+    if (!canvas) return;
+    canvas.addEventListener('touchstart', handlePointerDown, { passive: false });
+    canvas.addEventListener('touchmove', handlePointerMove, { passive: false });
+    canvas.addEventListener('touchend', handlePointerUp, { passive: false });
+    return () => {
+      canvas.removeEventListener('touchstart', handlePointerDown);
+      canvas.removeEventListener('touchmove', handlePointerMove);
+      canvas.removeEventListener('touchend', handlePointerUp);
+    };
+    // eslint-disable-next-line
+  }, [isDrawing, lastPosition, currentTool, color, thickness, shapes]);
+
   return (
     <div className="drawing-container">
       <div className="toolbar">
-        <button onClick={() => setCurrentTool('pencil')} className={`tool-button ${currentTool === 'pencil' ? 'active' : ''}`}>
-          ✏️
-        </button>
-        <button onClick={() => setCurrentTool('rectangle')} className={`tool-button ${currentTool === 'rectangle' ? 'active' : ''}`}>
-          🟨
-        </button>
-        <button onClick={() => setCurrentTool('circle')} className={`tool-button ${currentTool === 'circle' ? 'active' : ''}`}>
-          ⭕
-        </button>
-        <button onClick={handleUndo} className="tool-button" disabled={history.length === 0}>
-          ↺
-        </button>
-        <button onClick={handleRedo} className="tool-button" disabled={undoHistory.length === 0}>
-          ↻
-        </button>
+        <button onClick={() => setCurrentTool('pencil')} className={`tool-button ${currentTool === 'pencil' ? 'active' : ''}`}>✏️</button>
+        <button onClick={() => setCurrentTool('rectangle')} className={`tool-button ${currentTool === 'rectangle' ? 'active' : ''}`}>🟨</button>
+        <button onClick={() => setCurrentTool('circle')} className={`tool-button ${currentTool === 'circle' ? 'active' : ''}`}>⭕</button>
+        <button onClick={handleUndo} className="tool-button" disabled={history.length === 0}>↺</button>
+        <button onClick={handleRedo} className="tool-button" disabled={undoHistory.length === 0}>↻</button>
         <div className="color-picker">
-          <ChromePicker color={color} onChangeComplete={(color) => setColor(color.hex)} />
+          <ChromePicker color={color} onChangeComplete={(c) => setColor(c.hex)} />
         </div>
         <div className="thickness-controls">
-          <button onClick={() => setThickness(thickness - 1)} disabled={thickness <= 1}>➖</button>
+          <button onClick={() => setThickness(t => Math.max(1, t - 1))} disabled={thickness <= 1}>➖</button>
           <span>{thickness}</span>
-          <button onClick={() => setThickness(thickness + 1)}>➕</button>
+          <button onClick={() => setThickness(t => t + 1)}>➕</button>
         </div>
       </div>
       <div className="canvas-container">
         <canvas
           ref={canvasRef}
           className="drawing-canvas"
-          onMouseDown={handleMouseDown}
-          onMouseMove={handleMouseMove}
-          onMouseUp={handleMouseUp}
+          onMouseDown={handlePointerDown}
+          onMouseMove={handlePointerMove}
+          onMouseUp={handlePointerUp}
         />
       </div>
     </div>