diff --git a/reproducibility/site/public/_redirects b/reproducibility/site/public/_redirects
index d375bd3..19a8dd2 100644
--- a/reproducibility/site/public/_redirects
+++ b/reproducibility/site/public/_redirects
@@ -2,3 +2,7 @@
 # leaderboard.querygym.com.
 /leaderboard      /                      301
 /index.html       /                      301
+
+# Alias /sitemap.xml -> /sitemap-index.xml (200 = rewrite, not redirect).
+# GSC and other crawlers default to probing /sitemap.xml.
+/sitemap.xml      /sitemap-index.xml     200
diff --git a/reproducibility/site/src/layouts/Default.astro b/reproducibility/site/src/layouts/Default.astro
index 3a001a9..0ba8afa 100644
--- a/reproducibility/site/src/layouts/Default.astro
+++ b/reproducibility/site/src/layouts/Default.astro
@@ -11,13 +11,14 @@ interface Props {
 
 const { title, description } = Astro.props;
 
-// External links render the linkout icon and open in the current tab.
+// Top-menu linkout items (external: true) open in a new tab so the user
+// keeps their place on the leaderboard when they cross to a sibling site.
 const navLinks = [
   { label: "Datasets", href: "/datasets/" },
   { label: "Methods", href: "/methods/" },
   { label: "Models", href: "/models/" },
   { label: "About", href: "/about" },
-  { label: "Toolkit", href: "https://querygym.com", external: true },
+  { label: "Toolkit", href: "https://querygym.com", external: true, newTab: true },
 ];
 ---
 
diff --git a/web/site/public/_redirects b/web/site/public/_redirects
index 8314cd8..f390ca8 100644
--- a/web/site/public/_redirects
+++ b/web/site/public/_redirects
@@ -6,3 +6,10 @@
 /leaderboard         https://leaderboard.querygym.com/   301
 /leaderboard.html    https://leaderboard.querygym.com/   301
 /QueryGym/*          https://querygym.com/:splat         301
+
+# Alias the canonical /sitemap.xml path to the @astrojs/sitemap-generated
+# index. Google Search Console's "Add a sitemap" form auto-suggests
+# /sitemap.xml; tools like Bing/Yandex/IndexNow probe it; humans type it.
+# The 200 status is a rewrite (URL stays the same in the browser), not a
+# redirect — keeps the canonical URL for crawlers stable.
+/sitemap.xml         /sitemap-index.xml                  200
diff --git a/web/site/src/layouts/Default.astro b/web/site/src/layouts/Default.astro
index 18779c4..9d06fd2 100644
--- a/web/site/src/layouts/Default.astro
+++ b/web/site/src/layouts/Default.astro
@@ -33,17 +33,18 @@ const SITE = "https://querygym.com";
 const canonical = new URL(Astro.url.pathname, SITE).toString();
 const ogImageAbsolute = new URL(ogImage, SITE).toString();
 
-// External links use `external: true` (renders the linkout icon) and open in
-// the *current* tab — opening a new tab silently is a worse UX than letting
-// the user middle-click / cmd-click when they want a tab.
+// Top-menu linkout items (external: true) open in a new tab so the user
+// keeps their place on querygym.com when they leave to a sibling site.
+// Everywhere else on the page (footer, hero CTAs, ecosystem cards, in-page
+// citations) stays same-tab unless explicitly noted.
 const navLinks = [
   { label: "Install", href: "/install" },
   { label: "Methods", href: "/methods" },
   { label: "Reproducibility", href: "/reproducibility" },
   { label: "Cite", href: "/cite" },
-  { label: "Docs", href: "https://querygym.readthedocs.io", external: true },
-  { label: "Leaderboard", href: "https://leaderboard.querygym.com", external: true },
-  { label: "Dashboard", href: "https://dashboard.querygym.com", external: true },
+  { label: "Docs", href: "https://querygym.readthedocs.io", external: true, newTab: true },
+  { label: "Leaderboard", href: "https://leaderboard.querygym.com", external: true, newTab: true },
+  { label: "Dashboard", href: "https://dashboard.querygym.com", external: true, newTab: true },
 ];
 
 const fullTitle = `${title} — QueryGym`;