div.page_body {
    display: table-row;
}
div.col_left {
    display: table-cell;
}
div.col_main {
    display: table-cell;
}

div.col_left {
    /* would be better without fixed width */
    max-width: 20em;
}

div.col_left .thumb {
    padding: 3px;
}
div.col_left .thumbsel {
    padding: 2px;
    border: 1px solid blue;
}
div.col_left .thumbcap {
    color: black;
}

div.col_left .toc {
    float:left;
    clear:right; 
}
div.col_left .toc.float.right {
    float:right;
}