Add max-width to right and left panels

Signed-off-by: Aaron Raimist <aaron@raim.ist>

res/css/structures/_LeftPanel.scss

@@ -19,6 +19,7 @@ limitations under the License.
     display: flex;
     /* LeftPanel 260px */
     min-width: 260px;
+    max-width: 50%;
     flex: 0 0 auto;
 }
 

res/css/structures/_RightPanel.scss

@@ -20,6 +20,7 @@ limitations under the License.
     flex: 0 0 auto;
     position: relative;
     min-width: 264px;
+    max-width: 50%;
     display: flex;
     flex-direction: column;
 }