fix: separate contact section from footer for proper nav scroll

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

index.html

@@ -190,7 +190,8 @@
       </div>
     </section>
 
-    <footer id="contact" class="footer">
+    <section id="contact" class="section">
+      <h2 class="section-title">Contact</h2>
       <p>
         <a href="mailto:98kimsungmin@naver.com">98kimsungmin@naver.com</a>
         &nbsp;·&nbsp;
@@ -198,6 +199,10 @@
         &nbsp;·&nbsp;
         <a href="https://solved.ac/profile/tolelom" target="_blank" rel="noopener">Solved.ac</a>
       </p>
+    </section>
+
+    <footer class="footer">
+      <p>© 2026 김성민</p>
     </footer>
   </main>