Modified search box

I know that probably is non-related to a Theme, but it’s about modifying it…

I’ve been working on my Child Theme (couldn’t post into child themes forum don’t know why ), and got a strange problem… on the search bar provided by auction theme on the webpage header, when I set it to display with some opacity… it loses a button…I mean, the magnifier is no longer “clickable”…
If I don’t set any opacity, it works…

the code I’ve added to Design Setup > Custom Meta Data > Header Styles is:
[code title=”Custom Code”]
<style>
.wlt_searchbox input {width:700px !important; margin:40px;opacity:0.9;}
</style>[/code]

Here I’ve got some screenshots
1.- Without opacity, magnifier button working
2.- Opacity set at 0.9, magnifier button no longer “clickable”

Thank you