fix last item be cover after add view_count feature

修复增加阅读次数后，目录最后一项会被盖住的问题

static/css/kancloud.css

@@ -265,7 +265,7 @@ table>tbody>tr:hover{
     right: 0;
     overflow-y: auto;
     background-color: #fafafa;
-    margin-bottom: 35px;
+    margin-bottom: 60px;
 }
 
 .m-manual .manual-tab .tab-item.active {
@@ -1173,4 +1173,4 @@ table>tbody>tr:hover{
         opacity: .3;
         z-index: 3000
     }
-}
+}