#splashblock {
    position: absolute;
    left: 50%;
    top: 50%;
    width: 400px;
    height: 320px;
    margin-left: -200px; /* half of width */
    margin-top: -170px;  /* half of height */
    border-bottom: 1px dashed #aaa;
}

#splashblock img {
    width: 400px;
    height: 300px;
    border: 1px solid #aaa;
}

.nav {
    text-align: center;
}

.nav, a {
    font-size: x-small;
    font-weight: normal;
    text-decoration: none;
}