Fix footer overlap and improve sidebar layout

- Adjusted header height to account for fixed footer
- Improved footer positioning with background and border
- Reduced padding to prevent text overlap

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: DavidLiedle

assets/css/custom.css

@@ -100,8 +100,8 @@ blockquote {
     position: fixed;
     width: 270px;
     overflow-y: auto;
-    height: 100vh;
-    padding-bottom: 50px;
+    height: calc(100vh - 80px);
+    padding-bottom: 20px;
   }
 
   section {
@@ -111,7 +111,16 @@ blockquote {
   footer {
     position: fixed;
     bottom: 0;
+    left: 0;
     width: 270px;
+    background: white;
+    border-top: 1px solid #e5e5e5;
+    padding: 10px 20px;
+    margin: 0;
+  }
+
+  footer p {
+    margin: 5px 0;
   }
 }