修改添加题目功能

app/admin/view/tk/category.php

@@ -3,7 +3,7 @@
 <div class="layui-container" style="margin-top:30px;">
     <div class="layui-row">
         <div class="layui-col-md12">
-            <button class="layui-btn layui-btn-normal" id="addCategoryBtn">新增科目</button>
+            <button class="layui-btn layui-btn-normal mb-3" id="addCategoryBtn">新增科目</button>
             <table class="layui-hide" id="categoryTable" lay-filter="categoryTableFilter"></table>
         </div>
     </div>