Add modal to change username

Signed-off-by: Unknwon <joe2010xtmf@163.com>

public/ng/less/ui/alert.less

@@ -41,7 +41,15 @@
   border: 1px solid darken(@alertOrangeColor,10%);
   background-color: lighten(@alertOrangeColor,45%);
 }
-
-
-
+.white-popup-block {
+    background: #FFF;
+    padding: 20px 30px;
+    text-align: left;
+    max-width: 650px;
+    margin: 40px auto;
+    position: relative;
+    p {
+        font-size: 14px;
+    }
+}