body {
    max-width: 710px;
    margin: 0 auto;
    padding: 0;
    background-color: #FFF;
}
header img {
    width: 100%;
    max-width: 710px;
}

header, section {
    text-align: center;
}

section img {
    width: 49%;
    min-width: 300px;
}