fix: shorten Introduction tab to Intro, restore original padding

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: braboj

astro-site/src/data/site.json

@@ -5,7 +5,7 @@
   "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 & Merging", "href": "/branching-and-merging/" },
     { "label": "Remote Repos", "href": "/remote-repositories/" },

astro-site/src/styles/global.css

@@ -276,8 +276,8 @@ a:hover {
   font-size: var(--font-size-sm);
   font-weight: 500;
   text-transform: uppercase;
-  letter-spacing: 0.02em;
-  padding: 0 var(--space-sm);
+  letter-spacing: 0.04em;
+  padding: 0 var(--space-md);
   height: var(--tab-height);
   display: flex;
   align-items: center;