* {
    font-family: Helvetica, serif;
}
body {
    margin: 0;
}
header, footer {
    background: sienna;
    color: white;
    padding: 10px;
    text-align: center;
    clear: both;
}
#left, #right {
    background: navajowhite;
    width: 15%;
    height: 700px;
    float: left;
}
#center {
    width: 70%;
    height: 700px;
    overflow: auto;
    float: left;
}
img {
    width: 100%;
}
.php1_block {
    width: 46%;
    margin: 2%;
    position: relative;
    float: left;
}
h3, p, a {
    opacity: 0;
    position: absolute;
}
h3 {
    top: 5%;
}
p {
    top: 30%;
}
a {
    top: 70%;
    left: 70%;
    background: sienna;
    padding: 15px;
}
.php1_block:hover {
    img {
        opacity: 0.3;
        transition: 0.5s ease;
    }
    h3, p, a {
        opacity: 1;
    }
}