Darkening an image with :hover

by Ketan Patel

HTML

<button class="btn-img">
    <div class="img-wrap">
    <img src="http://upload.wikimedia.org/wikipedia/en/thumb/2/2a/Burj_Al_Arab,_Dubai,_by_Joi_Ito_Dec2007.jpg/220px-Burj_Al_Arab,_Dubai,_by_Joi_Ito_Dec2007.jpg" alt="Dubai" />
    </div>
</button>

CSS

.btn-img {
    display: block;
    margin: 0;
    padding: 0;
    border: 0;
    cursor: pointer;
    background-color: white;
    outline: 1px dotted blue;
}
.btn-img .img-wrap {
    margin: 10px;
}

.btn-img img {
    display: block;
}

.btn-img:hover .img-wrap {
    background-color: black;
}

.btn-img:hover img {
    opacity: 0.8;
}

.btn-img:hover img {
    opacity: 0.8;
}