Fixed flex issue between 980 and 960 pixels width

src/App.scss

@@ -213,18 +213,19 @@ nav {
 }
 
 .main {
-    flex: 1;
-    flex-basis: 65%;
+    flex-basis: 60%;
+    flex-grow: 1;
+    flex-shrink: 1;
 }
 
 .sidebar {
-    flex: 1;
-    flex-basis: 35%;
+  flex: 1;
+  flex-basis: 35%;
 }
 
 .sidebar-flexer {
   flex: 1;
-  flex-basis: 35%;
+  flex-basis: 345px;
   width: 365px;
 }
 
@@ -263,6 +264,8 @@ nav {
   }
   .sidebar-flexer {
     max-height: 96vh;
+    flex-shrink: 0;
+    flex-grow: 0;
   }
 }