feat:canvas样式优化

miniprogram/pages/copyBook/copyBook.less

@@ -158,7 +158,6 @@ page {
     background: #f8f9fa;
     border-radius: 12rpx;
     border: 2rpx dashed #dee2e6;
-    margin-top: 20rpx;
 }
 
 .canvas-content {

miniprogram/pages/index/index.less

@@ -130,10 +130,26 @@ page {
 }
 
 
+// .canvas-wrapper {
+//     width: 100%;
+//     background-color: #fff;
+//     box-sizing: border-box;
+// }
 .canvas-wrapper {
-    width: 100%;
-    background-color: #fff;
-    box-sizing: border-box;
+    display: flex;
+    justify-content: center;
+    align-items: center;
+    min-height: 400rpx;
+    background: #f8f9fa;
+    border-radius: 12rpx;
+    border: 2rpx dashed #dee2e6;
+}
+
+.canvas-content {
+    max-width: 100%;
+    border-radius: 8rpx;
+    box-shadow: 0 4rpx 12rpx rgba(0, 0, 0, 0.1);
+    overflow: hidden;
 }
 
 // #canvasContent {

miniprogram/pages/shape/index.less

@@ -14,7 +14,7 @@ page {
     .wrapper {
         background-color: #fff;
         border-radius: 20rpx;
-        padding: 0 24rpx;
+        padding: 36rpx 24rpx;
         box-shadow: 0 6rpx 8rpx rgba(0, 0, 0, 0.15);
         margin: 30rpx 0;
         display: flex;
@@ -23,7 +23,7 @@ page {
         .wrapper-title {
             font-size: 32rpx;
             color: #141414;
-            margin: 36rpx 0;
+            margin-bottom: 36rpx;
             font-weight: bold;
             text-align: center;
         }
@@ -85,6 +85,23 @@ page {
     }
 }
 
+.canvas-wrapper {
+    display: flex;
+    justify-content: center;
+    align-items: center;
+    min-height: 400rpx;
+    background: #f8f9fa;
+    border-radius: 12rpx;
+    border: 2rpx dashed #dee2e6;
+}
+
+.canvas-content {
+    max-width: 100%;
+    border-radius: 8rpx;
+    box-shadow: 0 4rpx 12rpx rgba(0, 0, 0, 0.1);
+    overflow: hidden;
+}
+
 .bottom-btn-box {
     position: fixed;
     left: 0;