Rework to level up once at a time

styles/levelup.less

@@ -28,6 +28,28 @@
         }
     }
 
+    .levelup-navigation-container {
+        display: flex;
+        align-items: center;
+        gap: 22px;
+
+        nav {
+            flex: 1;
+        }
+
+        .levelup-navigation-actions {
+            width: 306px;
+            display: flex;
+            justify-content: end;
+            gap: 16px;
+            margin-right: 4px;
+
+            * {
+                width: calc(50% - 8px);
+            }
+        }
+    }
+
     .tiers-container {
         display: flex;
         gap: 16px;