Update index.html

Author: QuLiao1117

index.html

@@ -340,7 +340,9 @@ <h2 class="title">BibTeX</h2>
 </section>
 <!--End BibTex citation -->
 
-<script type="text/javascript" id="clustrmaps" src="//clustrmaps.com/map_v2.js?d=l_pwfGfOMZ5wqA1GXPSrcEzT_5bvBF9ZRm3tTlZpW8Q&cl=ffffff&w=a"></script>
+<div style="width: 300px; margin: 0 auto;">
+  <script type="text/javascript" id="clustrmaps" src="//clustrmaps.com/map_v2.js?d=l_pwfGfOMZ5wqA1GXPSrcEzT_5bvBF9ZRm3tTlZpW8Q&cl=ffffff&w=a"></script>
+</div>
 
   <footer class="footer">
   <div class="container">