diff --git a/CLAUDE.md b/CLAUDE.md
index 7974b4b..9cf67a5 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -34,7 +34,7 @@ chapters/                  # SSG-agnostic tutorial content (canonical)
   02-building-blocks.md
   03-branching-and-merging.md
   04-remote-repositories.md
-  05-subprojects.md
+  05-nested-repositories.md
   06-expert-topics.md
   07-playbook.md
   08-appendix.md
diff --git a/README.md b/README.md
index c4677cb..3f7990e 100644
--- a/README.md
+++ b/README.md
@@ -35,7 +35,7 @@ directory.
 | 2 | [Building Blocks](chapters/02-building-blocks.md) | Repositories, objects, references, HEAD, tags |
 | 3 | [Branching and Merging](chapters/03-branching-and-merging.md) | Branches, merge strategies, rebase, cherry-pick, conflicts, stash |
 | 4 | [Remote Repositories](chapters/04-remote-repositories.md) | Clone, push, pull, fetch, remote tracking, forking workflows |
-| 5 | [Subprojects](chapters/05-subprojects.md) | Submodules and subtrees |
+| 5 | [Nested Repositories](chapters/05-nested-repositories.md) | Submodules and subtrees |
 | 6 | [Expert Topics](chapters/06-expert-topics.md) | Configuration, selectors, refspecs, hooks, bisect |
 | 7 | [Playbook](chapters/07-playbook.md) | Step-by-step recipes for common tasks |
 | 8 | [Appendix](chapters/08-appendix.md) | Merge strategies, SSH setup, Git clients, references |
diff --git a/astro-site/src/components/Header.astro b/astro-site/src/components/Header.astro
index 9cb8066..cb4b7a1 100644
--- a/astro-site/src/components/Header.astro
+++ b/astro-site/src/components/Header.astro
@@ -30,7 +30,7 @@ const base = import.meta.env.BASE_URL;
   </header>
 </div>
 
-<div class="site-tabs-bar">
+<div class="site-tabs-bar" style="overflow:hidden">
   <button class="nav-toggle" id="nav-toggle" aria-label="Open navigation menu" aria-expanded="false">
     <svg class="nav-toggle-icon" viewBox="0 0 24 24" width="22" height="22" fill="currentColor" aria-hidden="true">
       <path d="M3 18h18v-2H3v2zm0-5h18v-2H3v2zm0-7v2h18V6H3z"/>
diff --git a/astro-site/src/data/site.json b/astro-site/src/data/site.json
index e957637..ef6bc1c 100644
--- a/astro-site/src/data/site.json
+++ b/astro-site/src/data/site.json
@@ -5,12 +5,12 @@
   "repo": "https://github.com/braboj/tutorial-git",
   "tabs": [
     { "label": "Home", "href": "/" },
-    { "label": "Introduction", "href": "/introduction/" },
+    { "label": "Intro", "href": "/introduction/" },
     { "label": "Building Blocks", "href": "/building-blocks/" },
-    { "label": "Branching", "href": "/branching-and-merging/" },
-    { "label": "Remotes", "href": "/remote-repositories/" },
-    { "label": "Subprojects", "href": "/subprojects/" },
-    { "label": "Expert", "href": "/expert-topics/" },
+    { "label": "Branching & Merging", "href": "/branching-and-merging/" },
+    { "label": "Remote Repos", "href": "/remote-repositories/" },
+    { "label": "Nested Repos", "href": "/nested-repositories/" },
+    { "label": "Expert Topics", "href": "/expert-topics/" },
     { "label": "Playbook", "href": "/playbook/" },
     { "label": "Appendix", "href": "/appendix/" },
     { "label": "Glossary", "href": "/glossary/" }
diff --git a/astro-site/src/pages/index.astro b/astro-site/src/pages/index.astro
index 89a2ee8..cd6ba81 100644
--- a/astro-site/src/pages/index.astro
+++ b/astro-site/src/pages/index.astro
@@ -72,7 +72,7 @@ const headings = [
         <td>Clone, push, pull, fetch, remote tracking, forking workflows</td>
       </tr>
       <tr>
-        <td><a href={`${base}subprojects/`}>Subprojects</a></td>
+        <td><a href={`${base}nested-repositories/`}>Nested Repositories</a></td>
         <td>Submodules and subtrees for managing dependencies</td>
       </tr>
       <tr>
diff --git a/astro-site/src/styles/global.css b/astro-site/src/styles/global.css
index 324c081..950b7a7 100644
--- a/astro-site/src/styles/global.css
+++ b/astro-site/src/styles/global.css
@@ -267,7 +267,6 @@ a:hover {
 .site-tabs {
   display: flex;
   padding: 0 var(--space-md);
-  overflow-x: auto;
   max-width: calc(var(--max-content) + 2 * var(--sidebar-width) + 2 * var(--space-xl));
   margin: 0 auto;
 }
@@ -278,7 +277,7 @@ a:hover {
   font-weight: 500;
   text-transform: uppercase;
   letter-spacing: 0.04em;
-  padding: 0 var(--space-md);
+  padding: 0 var(--space-sm);
   height: var(--tab-height);
   display: flex;
   align-items: center;
diff --git a/chapters/05-subprojects.md b/chapters/05-nested-repositories.md
similarity index 99%
rename from chapters/05-subprojects.md
rename to chapters/05-nested-repositories.md
index 14bfb92..77db48b 100644
--- a/chapters/05-subprojects.md
+++ b/chapters/05-nested-repositories.md
@@ -1,6 +1,6 @@
 ---
-title: "Subprojects"
-section: "subprojects"
+title: "Nested Repositories"
+section: "nested-repositories"
 order: 5
 ---
 
diff --git a/chapters/09-glossary.md b/chapters/09-glossary.md
index d01432e..c66aa10 100644
--- a/chapters/09-glossary.md
+++ b/chapters/09-glossary.md
@@ -49,8 +49,8 @@ A reference of key Git terms used throughout this tutorial, with links to the ch
 | Revert | Create a new commit that undoes a previous commit's changes without rewriting history | [7](07-playbook.md) |
 | Squash merge | Combine all commits from a branch into a single change set on the target branch — no merge commit | [3](03-branching-and-merging.md) |
 | Stash | Save uncommitted changes temporarily so you can switch branches with a clean working tree | [3](03-branching-and-merging.md) |
-| Submodule | A reference to a specific commit in another repository — stores URL and hash, not files | [5](05-subprojects.md) |
-| Subtree | A full copy of another repository merged into a subdirectory of the parent project | [5](05-subprojects.md) |
+| Submodule | A reference to a specific commit in another repository — stores URL and hash, not files | [5](05-nested-repositories.md) |
+| Subtree | A full copy of another repository merged into a subdirectory of the parent project | [5](05-nested-repositories.md) |
 | Tag | A named reference to a commit — annotated (object with metadata) or lightweight (plain reference) | [2](02-building-blocks.md) |
 | Tree | Object that represents a directory — lists blobs and other trees with names and permissions | [2](02-building-blocks.md) |
 | Upstream | Conventional name for the original repository you forked from | [4](04-remote-repositories.md) |
diff --git a/docs/ONBOARDING.md b/docs/ONBOARDING.md
index 05768bc..3572f25 100644
--- a/docs/ONBOARDING.md
+++ b/docs/ONBOARDING.md
@@ -71,7 +71,7 @@ files for the web version.
 02-building-blocks.md      07-playbook.md
 03-branching-and-merging.md 08-appendix.md
 04-remote-repositories.md  09-glossary.md
-05-subprojects.md
+05-nested-repositories.md
 ```
 
 Chapter structure, writing conventions, and figure style rules are
diff --git a/docs/dev-journal.md b/docs/dev-journal.md
index 6935d54..80b542d 100644
--- a/docs/dev-journal.md
+++ b/docs/dev-journal.md
@@ -74,7 +74,7 @@ Architecture overview and chronological session log for tutorial-git.
 02-building-blocks.md
 03-branching-and-merging.md
 04-remote-repositories.md      ← NEW
-05-subprojects.md              ← NEW (split from deep internals)
+05-nested-repositories.md      ← NEW (split from deep internals)
 06-expert-topics.md            ← renamed, overhauled
 07-playbook.md                 ← rewritten as recipes
 08-appendix.md                 ← trimmed + SSH