[data-mce-p-class="ephoto-dam-embed"] {
    border:0 !important;
    outline: 0 !important
}

[data-mce-p-class="ephoto-dam-embed"] iframe {
    border: 3px solid transparent;
    border-radius: 3px 
}

[data-mce-p-class="ephoto-dam-embed"][data-mce-selected] iframe {
   border: 3px solid #2276d2
}