style(css): 优化问卷设计和预览样式

- 添加自定义复选框和单选按钮样式
- 调整矩阵问题表格样式
- 优化 NPS 问题布局
- 统一预览组件属性命名
-调整部分颜色变量

src/views/Survey/Index.vue

@@ -72,7 +72,7 @@
             <!--        <el-space direction="horizontal">-->
             <div>
               <el-button :disabled="item.source === 0" @click="deleteItem(item)"> 删除</el-button>
-              <el-button :disabled="item.source === 0" @click="copyItem(item)"> 复制</el-button>
+              <!--              <el-button :disabled="item.source === 0" @click="copyItem(item)"> 复制</el-button>-->
               <el-button style="border: 2px solid #71b73c" @click="toPreview(item)">
                 <el-text style="color: #71b73c">预览</el-text>
               </el-button>
@@ -96,6 +96,7 @@
                   :close-on-click-overlay="false"
                   :close-on-click-outside="false"
                 >
+                  <el-dropdown-item @click="copyItem(item)">复制</el-dropdown-item>
                   <el-dropdown-item @click="editItem(item)">编辑</el-dropdown-item>
                   <el-dropdown-item @click="saveTemplate(item)">存为模板</el-dropdown-item>
                 </el-dropdown-menu>