diff --git a/components/_partials/components.css b/components/_partials/components.css
index 2aa4f261..7a7d41cd 100644
--- a/components/_partials/components.css
+++ b/components/_partials/components.css
@@ -189,7 +189,7 @@ a.component-list-header-text:hover ~ div.component-list-icon p a i.component-lin
   display: flex;
   align-items: flex-end;
   justify-content: flex-end;
-  border-bottom: 1px solid #E9ECEF;
+  border-bottom: 1px solid #ffffff;
   border-top: none;
   border-left: none;
   border-right: none;
@@ -215,11 +215,10 @@ main a.nav-link:hover {
   color: #202020;
   background-color: #fff;
   border-bottom: 3px solid #202020 !important;
-  margin-bottom: -2px;
-  border-left: 1px solid rgba(0, 0, 0, 0);
-  border-right: 1px solid rgba(0, 0, 0, 0);
-  border-top: 1px solid rgba(0, 0, 0, 0);
-  border-radius: 0px;
+  margin-bottom: 0px;
+  border-left: 0px solid rgba(0, 0, 0, 0);
+  border-right: 0px solid rgba(0, 0, 0, 0);
+  border-top: 0px solid rgba(0, 0, 0, 0);
 }
 
 .panel-tabset .nav-tabs .nav-link:hover,
@@ -232,8 +231,8 @@ main a.nav-link:hover {
 }
 
 .panel-tabset .nav-tabs .nav-link {
-  padding: 0.35rem 1.25rem;
-  margin-bottom: 0px;
+  padding: 0.45rem 1.25rem;
+  margin-bottom: 2px;
 }
 
 .iframe-border {
diff --git a/include-in-header.html b/include-in-header.html
index 2398245b..3cde5f87 100644
--- a/include-in-header.html
+++ b/include-in-header.html
@@ -75,7 +75,8 @@
   function addWhatsShinyExpressTooltip() {
     const tooltipContents = `<p><strong>Shiny Express</strong> is a new, streamlined way to write a Shiny app.</p>
     <p><strong>Shiny Core</strong> refers to the original, functional Shiny syntax, which is still a great way to write Shiny apps.</p>
-    <p class="text-right" style="font-size:0.85em;"><a href="/docs/express-introduction.qmd">Read more<i class="bi bi-chevron-right"></i></a></p>`
+    <p class="fw-600" style="font-size:0.85em;"><a href="/docs/express-introduction.html">Read more <i class="bi bi-chevron-right align-text-top"></i></a></p>`
+
 
     const tooltipDisplay = `<i class="bi bi-question-circle-fill d-inline d-sm-none"></i><span class="d-none d-sm-inline">What's the difference?</span>`
 
@@ -92,7 +93,7 @@
 
       new window.bootstrap.Popover(trigger, {
         html: true,
-        title: "What's Shiny Express?",
+        title: "Express vs Core",
         content: tooltipContents,
         placement: 'auto',
         trigger: 'click',
diff --git a/quarto-style.scss b/quarto-style.scss
index dcc63962..ab669d8f 100644
--- a/quarto-style.scss
+++ b/quarto-style.scss
@@ -1724,21 +1724,36 @@ btn.action-button:hover {
 
 .what-shiny-express {
   position: absolute;
-  top: 0.7em;
+  top: 0.78em;
   right: 1.2em;
   font-size: 0.85em;
   cursor: pointer;
 }
 
 .shiny-mode-tabset[data-group="shiny-app-mode"] > .what-shiny-express {
-  color: white;
+  color: $gray-900;
+}
+
+.popover {
+  max-width: 300px;
+  border: 1px solid $gray-400;
+  box-shadow: 0px 1px 2px rgba(29,31,33,.1),
+  0px 2px 3px rgba(29,31,33,.1),
+  0px 3px 8px rgba(29,31,33,.08);
 }
 
+
 .popover-header {
   margin-top: 0;
+  background-color: $gray-900;
+  color: $gray-100;
+  padding: .6rem 1rem;
+  font-size: .8rem;
+  font-weight: 700;
 }
 
 .popover-body {
+  font-size: .85rem;
   > :first-child {
     margin-top: 0;
   }