CSS style for hiding graphical content

hide_unless_hover.css

/* Hides most graphical content by default unless you need to see it.
/* NOTE: can be used in Stylish as a theme */

/* Hide some of the annoying background images (but not all...) */
table div {
  background-image: none !important;
}

/* Hide any element that has `src` attribute (images, youtube videos, thumbnails, etc) */
/* May hide control elements like buttons, but they will be visible by an outline      */
*[src] {
  filter: contrast(0%) brightness(180%) drop-shadow(0px 0px 1px);
  /*filter: opacity(2%);*/
}

/* Make a hidden element visible by hovering on it */
 *[src]:hover {
	filter: contrast(100%) opacity(100%);
}