I have a file upload button with a weird styling issue that I can’t seem to solve. the generated HTML is as follows:
<div id="uniform-file_upload" class="uploader">
<input id="file_upload" type="file" multiple="multiple" name="file_upload" size="55" style="opacity: 0;">
<span class="filename" style="-moz-user-select: none;">No file selected</span>
<span class="action" style="-moz-user-select: none;">Choose File</span>
</div>
And the output is as follows:

Can you see the little box around the words “Choose file”? Well, it is very ugly and distracting and I thought it should be easy to get rid of it but I can’t do it.
In a situation like this, a good debugging trick would be to use the Chrome web browser and try the Inspect Element option. Right-click the form button (in your web page) and choose “Inspect Element” (FireFox has something similar, but I prefer the Chrome one)
The Styles information for the button appears on the side panel and you can tweak the styles to get the required effect.
NB: Verify you have selected the correct html tag in the Elements tab section after clicking Inspect Element. Also, element.style {…} is an option in the side panel and it allows you to edit the inline css for the selected html element.