问题
Take a look at this page in IE (I have the newest version, but it also happens in older versions.)
http://tinuska.vibraflex.cz/
In above link there are two round buttons at bottom of the page. When you click the button, a semi-transparent highlight around the button appears. It doesn't appear in Mozilla or Chrome. Is it possible to remove it somehow?

回答1:
Add an extra style in anchor tag.
style="background-color:transparent"
回答2:
TRY It. The below code of css is useful for remove the border and focus around the link or button.
a:focus{
outline:none !important;
}
回答3:
To solve your problem you can add these style attributes to your anchor buttons btn1 and btn2:
border-top-left-radius: 41px;
border-top-right-radius: 41px;
border-bottom-left-radius: 41px;
border-bottom-right-radius: 41px;
I've tried with IE10 and it's working.
An example for btn1:
<a id="btn1" href="#" style="border-top-left-radius: 41px; border-top-right-radius: 41px; border-bottom-right-radius: 41px; border-bottom-left-radius: 41px;"/>
来源:https://stackoverflow.com/questions/18101342/ie-css-how-to-remove-a-highlight-which-appears-when-click-the-button