CSS と HTML を使用して画像オーバーレイを作成する方法

.image-container {
    position: relative;
    width: 200px;
    height: 300px;
}
.image-container .after {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: none;
    color: #FFF;
}
.image-container:hover .after {
    display: block;
    background: rgba(0, 0, 0, .6);
}

<div class="image-container">
    <img src="http://lorempixel.com/300/200" />
    <div class="after">This is some content</div>
</div>

<code class="css">.image-container .after .content {
    position: absolute;
    bottom: 0;
    font-family: Arial;
    text-align: center;
    width: 100%;
    box-sizing: border-box;
    padding: 5px;
}
.image-container .after .zoom {
    color: #DDD;
    font-size: 48px;
    position: absolute;
    top: 50%;
    left: 50%;
    margin: -30px 0 0 -19px;
    height: 50px;
    width: 45px;
    cursor: pointer;
}
.image-container .after .zoom:hover {
    color: #FFF;
}</code>

<code class="html"><link href="//netdna.bootstrapcdn.com/font-awesome/4.0.3/css/font-awesome.min.css" rel="stylesheet"/>

<div class="image-container">
    <img src="http://lorempixel.com/300/180" />
    <div class="after">
        <span class="content">This is some content. It can be long and span several lines.</span>
        <span class="zoom">
            <i class="fa fa-search"></i>
        </span>
    </div>
</div></code>