细节优化

application/index/view/default/public/header_nav.html

@@ -39,7 +39,7 @@
                     <input type="text" name="keywords" class="am-form-field" placeholder="其实搜索很简单^_^ !" value="{{if !empty($params['keywords'])}}{{$params.keywords}}{{/if}}" autocomplete="off" />
                     <span class="am-input-group-btn">
                         <button class="am-btn am-btn-default" type="submit">
-                            <span class="am-icon-search am-icon-sm"></span>
+                            <span class="am-icon-search am-icon-xs"></span>
                         </button>
                     </span>
                 </div>