DOC-1722 : Fix CCIP tutorials scrolling issue (#3273)

Author: SyedAsadKazmi

src/components/LeftSidebar/leftSidebar.module.css

@@ -1,19 +1,24 @@
 .nav {
-  padding-bottom: calc(2 * var(--doc-padding));
   width: 100%;
-  height: calc(100vh - var(--space-16x)); /* Subtract header height */
+  height: calc(100vh - var(--space-16x));
+  /* Subtract header height */
   position: sticky;
-  top: var(--space-16x); /* Header height */
-  overflow: hidden; /* Prevent nav overflow */
+  top: var(--space-16x);
+  /* Header height */
+  overflow: hidden;
+  /* Prevent nav overflow */
+  display: flex;
+  flex-direction: column;
 }
 
 .sidebarDropdowns {
   padding-top: var(--space-3x);
+  flex-shrink: 0;
 }
 
 .navGroups {
-  padding: var(--doc-padding) var(--space-8x) var(--doc-padding) 0;
-  height: 100%;
+  padding: var(--doc-padding) var(--space-8x) calc(2 * var(--doc-padding)) 0;
+  flex: 1;
   overflow-y: auto;
   scrollbar-width: thin;
   scrollbar-color: var(--gray-300) transparent;