/* indicate media without a description
initial code by Paul (https://linernotes.club/@balrogboogie), expanded upon by FiXato (https://contact.fixato.org)
related discussion: https://dragonscave.space/@Mayana/106443499687608116.
Feel free to reuse it; it's public domain (https://linernotes.club/@balrogboogie/106681622019395866) */
.media-gallery__item-thumbnail img:not([alt]),
.audio-player__canvas:not([title]),
.video-player video:not([title]), 
.media-gallery__gifv video:not([title])
 {
    border: 2px solid red;
    box-sizing: border-box;
}