diff --git a/lib/src/card_animation.dart b/lib/src/card_animation.dart
index 0c88aea..6ccba0a 100644
--- a/lib/src/card_animation.dart
+++ b/lib/src/card_animation.dart
@@ -1,9 +1,8 @@
-import 'dart:math';
+import 'dart:math' as math;
 import 'dart:ui';
 
 import 'package:flutter/widgets.dart';
 import 'package:flutter_card_swiper/flutter_card_swiper.dart';
-import 'package:flutter_card_swiper/src/extensions.dart';
 
 class CardAnimation {
   CardAnimation({
@@ -13,8 +12,7 @@ class CardAnimation {
     required this.initialOffset,
     this.isHorizontalSwipingEnabled = true,
     this.isVerticalSwipingEnabled = true,
-  })  : scale = initialScale,
-        difference = initialOffset;
+  }) : scale = initialScale;
 
   final double maxAngle;
   final double initialScale;
@@ -28,14 +26,14 @@ class CardAnimation {
   double total = 0;
   double angle = 0;
   double scale;
-  Offset difference;
+  Offset difference = Offset.zero;
 
   late Animation<double> _leftAnimation;
   late Animation<double> _topAnimation;
   late Animation<double> _scaleAnimation;
   late Animation<Offset> _differenceAnimation;
 
-  double get _maxAngleInRadian => maxAngle * (pi / 180);
+  double get _maxAngleInRadian => maxAngle * (math.pi / 180);
 
   void sync() {
     left = _leftAnimation.value;
@@ -51,7 +49,7 @@ class CardAnimation {
     total = 0;
     angle = 0;
     scale = initialScale;
-    difference = initialOffset;
+    difference = Offset.zero;
   }
 
   void update(double dx, double dy, bool inverseAngle) {
@@ -68,27 +66,36 @@ class CardAnimation {
   }
 
   void updateAngle(bool inverse) {
-    if (angle.isBetween(-_maxAngleInRadian, _maxAngleInRadian)) {
-      angle = _maxAngleInRadian * left / 1000;
-      if (inverse) angle *= -1;
-    }
+    angle = clampDouble(
+      _maxAngleInRadian * left / 1000,
+      -_maxAngleInRadian,
+      _maxAngleInRadian,
+    );
+    if (inverse) angle *= -1;
   }
 
   void updateScale() {
-    scale = (total > 0)
-        ? clampDouble(initialScale + (total / 5000), initialScale, 1.0)
-        : clampDouble(initialScale - (total / 5000), initialScale, 1.0);
+    scale = clampDouble(initialScale + (total.abs() / 5000), initialScale, 1.0);
   }
 
   void updateDifference() {
-    final discrepancy = (total > 0) ? total / 10 : -(total / 10);
+    final discrepancy = (total / 10).abs();
 
-    if (difference.dx.isBetween(0, initialOffset.dx)) {
-      difference = Offset(initialOffset.dx + discrepancy, difference.dy);
+    var diffX = 0.0, diffY = 0.0;
+
+    if (initialOffset.dx > 0) {
+      diffX = discrepancy;
+    } else if (initialOffset.dx < 0) {
+      diffX = -discrepancy;
     }
-    if (difference.dy.isBetween(0, initialOffset.dy)) {
-      difference = Offset(difference.dx, initialOffset.dy + discrepancy);
+
+    if (initialOffset.dy < 0) {
+      diffY = -discrepancy;
+    } else if (initialOffset.dy > 0) {
+      diffY = discrepancy;
     }
+
+    difference = Offset(diffX, diffY);
   }
 
   void animate(BuildContext context, CardSwiperDirection direction) {
@@ -123,7 +130,7 @@ class CardAnimation {
     ).animate(animationController);
     _differenceAnimation = Tween<Offset>(
       begin: difference,
-      end: Offset.zero,
+      end: initialOffset,
     ).animate(animationController);
     animationController.forward();
   }
@@ -145,7 +152,7 @@ class CardAnimation {
     ).animate(animationController);
     _differenceAnimation = Tween<Offset>(
       begin: difference,
-      end: Offset.zero,
+      end: initialOffset,
     ).animate(animationController);
     animationController.forward();
   }
@@ -165,7 +172,7 @@ class CardAnimation {
     ).animate(animationController);
     _differenceAnimation = Tween<Offset>(
       begin: difference,
-      end: initialOffset,
+      end: Offset.zero,
     ).animate(animationController);
     animationController.forward();
   }
@@ -201,7 +208,7 @@ class CardAnimation {
       end: scale,
     ).animate(animationController);
     _differenceAnimation = Tween<Offset>(
-      begin: Offset.zero,
+      begin: initialOffset,
       end: difference,
     ).animate(animationController);
     animationController.forward();
@@ -223,7 +230,7 @@ class CardAnimation {
       end: scale,
     ).animate(animationController);
     _differenceAnimation = Tween<Offset>(
-      begin: Offset.zero,
+      begin: initialOffset,
       end: difference,
     ).animate(animationController);
     animationController.forward();
diff --git a/lib/src/card_swiper.dart b/lib/src/card_swiper.dart
index bde5257..6a075de 100644
--- a/lib/src/card_swiper.dart
+++ b/lib/src/card_swiper.dart
@@ -1,5 +1,5 @@
 import 'dart:collection';
-import 'dart:math';
+import 'dart:math' as math;
 
 import 'package:flutter/widgets.dart';
 import 'package:flutter_card_swiper/src/card_animation.dart';
@@ -157,10 +157,6 @@ class CardSwiper extends StatefulWidget {
           initialIndex >= 0 && initialIndex < cardsCount,
           'initialIndex must be between 0 and [cardsCount]',
         ),
-        assert(
-          backCardOffset >= Offset.zero,
-          'backCardOffset must be a positive value',
-        ),
         super(key: key);
 
   @override
@@ -227,9 +223,7 @@ class _CardSwiperState<T extends Widget> extends State<CardSwiper>
                 clipBehavior: Clip.none,
                 fit: StackFit.expand,
                 children: List.generate(numberOfCardsOnScreen(), (index) {
-                  if (index == 0) {
-                    return _frontItem(constraints);
-                  }
+                  if (index == 0) return _frontItem(constraints);
 
                   return _backItem(constraints, index);
                 }).reversed.toList(),
@@ -287,15 +281,15 @@ class _CardSwiperState<T extends Widget> extends State<CardSwiper>
     );
   }
 
-  Widget _backItem(BoxConstraints constraints, int offset) {
+  Widget _backItem(BoxConstraints constraints, int index) {
     return Positioned(
-      top: _cardAnimation.difference.dy * offset,
-      left: _cardAnimation.difference.dx * offset,
+      top: (widget.backCardOffset.dy * index) - _cardAnimation.difference.dy,
+      left: (widget.backCardOffset.dx * index) - _cardAnimation.difference.dx,
       child: Transform.scale(
-        scale: _cardAnimation.scale - ((1 - widget.scale) * (offset - 1)),
+        scale: _cardAnimation.scale - ((1 - widget.scale) * (index - 1)),
         child: ConstrainedBox(
           constraints: constraints,
-          child: widget.cardBuilder(context, getValidIndexOffset(offset)!),
+          child: widget.cardBuilder(context, getValidIndexOffset(index)!),
         ),
       ),
     );
@@ -426,7 +420,7 @@ class _CardSwiperState<T extends Widget> extends State<CardSwiper>
       return 0;
     }
 
-    return min(
+    return math.min(
       widget.numberOfCardsDisplayed,
       widget.cardsCount - _currentIndex!,
     );