feat: 优化页面样式

miniprogram/pages/shape/index.wxml

@@ -5,20 +5,19 @@
             <toy-button
                 type="green"
                 bind:click="handleSelectShape"
-                width="290rpx">
+                width="100%">
                 选择图形
             </toy-button>
             <toy-button
                 type="primary"
                 bind:click="refreshShapeCard"
-                width="290rpx"
+                width="100%"
                 icon="refresh"
                 icon-class-prefix="toy-icon">
                 随机生成
             </toy-button>
         </view>
-        <van-divider />
-        <view class="shape-list">
+        <view class="shape-list" wx:if="{{shapeList.length > 0}}">
             <shape-card
                 wx:for="{{ shapeList }}"
                 wx:for-item="item"
@@ -31,6 +30,15 @@
                 bind:onDelete="onDelete"
                 bind:onColorTap="onColorTap" />
         </view>
+        <view class="shape-list-empty" wx:if="{{!shapeList.length}}">
+            <view class="empty-icon">
+                <text class="toy-icon toy-icon-guide"></text>
+            </view>
+            <view class="empty-title">还没有选择图形</view>
+            <view class="empty-desc"
+                >请点击上方“选择图形”或使用“随机生成”开始创建</view
+            >
+        </view>
     </view>
     <shape-picker
         selectedShapeList="{{shapeList}}"