Subscibe Page: Responsive Design

Hi all!

I want to create a responsive subscribe page. I put all needed CSS in the configuration of the subsribe page, so that the header and the footer are really responsive, so I can view it on my smartphone.

But when I press the link for subscripton there, it looks really awful:

One look in the HTML-Code and I saw this:

< input type=“text” name=“attribute1” class=“attributeinput” size=“40” value="" />

I think that the size=“40” is that disturbing thing. So, how do I change it? Does anybody know that?

Greets, arada

I found something:

I could change the value here, but how do I remove the whole string “size=XXX”? I think it’s somewhere in the index.php, but where?

Much better would be that the input field is always in all screen resolutions in the whole row:

Somebody can help me?