Fix copy and auto-resize iframe to content height

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: jsundai

docs/nexus-demo.mdx

@@ -18,7 +18,18 @@ hide_table_of_contents: true
 `}</style>
 
 <iframe
+  id="nexus-demo-frame"
   src="/nexus-demo.html"
-  style={{display: 'block', width: '100%', height: 'calc(100vh - 60px)', border: 'none'}}
+  style={{display: 'block', width: '100%', height: '100vh', border: 'none'}}
   title="Temporal Nexus Interactive Demo"
+  onLoad={() => {
+    const frame = document.getElementById('nexus-demo-frame');
+    const resize = () => {
+      try {
+        frame.style.height = frame.contentDocument.body.scrollHeight + 'px';
+      } catch(e) {}
+    };
+    resize();
+    frame.contentWindow.addEventListener('click', () => setTimeout(resize, 400));
+  }}
 />

static/nexus-demo.html

@@ -403,7 +403,7 @@ <h3>Cross-Everything</h3>
 <div id="components" class="section">
   <div class="progress-bar"><div class="progress-fill" style="width:33%"></div></div>
   <h1>The Four Building Blocks</h1>
-  <p class="lead">Nexus has four key concepts. Understanding these unlocks everything else.</p>
+  <p class="lead">Nexus has four key concepts. These four concepts are the foundation of everything in Nexus.</p>
 
   <div style="display:flex;flex-direction:column;gap:20px;">