A tag is being replicated

The following code in the footer is producing multiple copies of the <a/> tag, screen shot attached. What went wrong?

<div style="text-align:center">
  <h3>
    Decisive Wife
  </h3>
  <a href="https://apps.apple.com/us/app/" style="display:inline-block; overflow:hidden; background:url(/s/Download_on_the_App_Store_Badge.svg) no-repeat; width:135px; height:40px;"/>
</div>

your code will apply to all a tag entire site.

<a href="https://apps.apple.com/us/app/" style="display:inline-block; overflow:hidden; background:url(/s/Download_on_the_App_Store_Badge.svg) no-repeat; width:135px; height:40px;"/>

edit it to

<a href="https://apps.apple.com/us/app/" class="tuanphan"/>

and insert this to Design > Custom CSS

.tuanphan {
  display:inline-block; 
  overflow:hidden; 
  background:url(/s/Download_on_the_App_Store_Badge.svg) no-repeat; 
  width:135px; 
  height:40px;
}