feal: Fix admin site page UI gtitch - MEED-3362 - Meeds-io/MIPs#113 (#…

…3519)

Before this PR, there is a UI glitch in the admin page due to the breakpoints review.
This change allows to fix the admin page display and adapt its breakpoints with the platform breakpoints.

(cherry picked from commit 60dec5a)

webapp/portlet/src/main/webapp/skin/less/common/AdministrationSite/Style.less

@@ -18,7 +18,10 @@
 
 */
 
-@media (min-width: 1280px) {
+@import "../../variables.less";
+@import "../../mixins.less";
+
+@media (min-width: @minDesktop) {
   .administrationSiteVerticalMenuContainerClass {
     width: 310px !important;
   }
@@ -27,7 +30,7 @@
   }
 }
 
-@media (max-width: 1279px) {
+@media (max-width: @maxLargeTabletWidth) {
   .administrationSiteVerticalMenuContainerClass {
     width: 0px !important;
   }
@@ -39,7 +42,7 @@
   }
 }
 
-@media (max-width: 979px) {
+@media (max-width: @maxTabletWidth) {
   .administrationSiteVerticalMenuContainerClass {
     width: 0px !important;
   }
@@ -49,4 +52,4 @@
     margin-right: 0px ~'!important; /** orientation=rt */ ';
     margin-top: -30px;
   }
-}
+}