fix: fix side bar styles to accommodate header announcement heights (#…

…163) (#164)

Co-authored-by: Fran McDade <franmcdade@Frans-MacBook-Pro.local>

src/components/Layout/components/Sidebar/components/SidebarPositioner/sidebarPositioner.styles.ts

@@ -6,6 +6,7 @@ interface Props {
 }
 
 export const SidebarPositioner = styled("div")<Props>`
+  box-sizing: border-box;
   height: 100%;
   overflow: visible;
   padding: 16px 0;