image-caption.css

/* add alt-text of images as caption */
.image-embed[alt]:not([alt$=".png"], [alt$=".jpg"], [alt$=".jpeg"], [alt$=".tiff"])::after {
	content: attr(alt);
	font-style: italic;
	color: var(--text-muted);
}

/* centers image caption */
.image-embed[alt]::after {
	text-align: center;
	display: block;
}

/* center image itself */
.view-content img:not(.emoji) {
	display: block;
	margin-right: auto;
	margin-left: auto;
}