$max_image_height: 150px; .chat-message { // append selectors to set images to a // max height of $max_image_height .chat-message-collapser .onebox img:not(.ytp-thumbnail-image), .chat-message-collapser img.onebox, .chat-message-collapser .chat-uploads img, .chat-message-collapser p img, aside.onebox .onebox-body .aspect-image-full-size, aside.onebox .onebox-body .aspect-image-full-size img { object-fit: contain; max-height: $max_image_height; max-width: 100%; width: unset; overflow: hidden; } .chat-message-collapser .chat-message-collapser-header + div .chat-message-collapser-youtube { object-fit: contain; height: $max_image_height; width: calc(#{$max_image_height} / 9 * 16); } }