Unable to change background color when hover

HTML-CSS
1

Hi, I’m trying to work out how to change the color from black to grey when I hover over a button.

.contact-us a:hover{width:185px; height:49px; text-align:center; font-weight:bold; color:#fff; background-color: grey; font-size:17px; text-transform:uppercase;
line-height: 45px; margin:0 0 0; border-radius:5px; left:40%; box-shadow: 0px 1px 1px grey; float:left; background-image: -webkit-linear-gradient(grey);
background-image: -moz-linear-gradient(grey);
background-image: -ms-linear-gradient(grey);
background-image: -o-linear-gradient(grey);
background-image: linear-gradient(grey); transition: all 0.5s ease-in-out 0s;}

What am i doing wrong here?

Thanks,

Jeremy

2

Give your element some id then apply hover style like:

#myElement : hover {
    background-color: Red;
}

Hope you get my point.