Google resposive ad is not responsive

[gunsock]

I’ve tried to put an adsense responsive ad in my new responsive page at:

Judith Anderson - Hollywood's Golden Age

but its size doesn’t change with screen size.
I put it in my topcontent div which has this CSS:

#topcontent {
  text-align:center;
 width:90%;
 margin:0 auto 5px;
 background:#000;
   border-radius:6px;
   color:#FEE680;
   padding:5px;
   font-weight:bold;
}

Could anyone help me please with what I’m doing wrong?
Many thanks,
Chris

EDIT
This post has been reformatted by enclosing the code block in 3 backticks
```
on their own lines.

[RyanReese]

The responsive ad will only resize to fit the container upon initial page load. You have the wrong idea about what google responsive ads are.

[gunsock]

I’ve just tried accessing my site in mobile view, and it works perfectly. I see what you mean, Ryan. I just didn’t understand. Now I do. Once again, many thanks.
Chris