[css-color-5] Added a "none" option to the image form of light-dark(), #12513

Author: svgeesus

css-color-5/Overview.bs

@@ -2807,6 +2807,15 @@ or any other color or monochrome output device which has been characterized.
 	if the <a>used color scheme</a> is ''light'' or unknown,
 	or the second image,
 	if the <a>used color scheme</a> is ''dark''.
+	The none keyword 
+	produces a fully transparent image 
+	with no natural size. 
+
+	It is equivalent to a single-stop gradient whose stop color is ''transparent''':
+
+	<pre class="lang-css">
+		linear-gradient(transparent)
+	</pre>
 
 	<div class="example" id="ex-light-dark-color">
 		For example, to maintain a legible contrast on links,
@@ -2847,7 +2856,15 @@ or any other color or monochrome output device which has been characterized.
 				);
 			}
 		</pre>
+		</div>
 
+		<div class="example" id="ex-light-dark-none">
+			For example, a raster image is used in light mode, 
+			while in dark mode we want a fully-transparent image. 
+
+			<pre class="lang-css">
+				background-image: light-dark(url(my-light-image.png), none);
+			</pre>
 		</div>
 
 
@@ -3808,6 +3825,9 @@ This specification adds a way to ensure adequate contrast for text whose backgro
 		which takes a pair of images rather than a pair of colors
 		(<a href="https://github.com/w3c/csswg-drafts/issues/12513">Issue 12513</a>)
 	</li>
+	<li>Added a "none" option to the image form of light-dark()
+		(<a href="https://github.com/w3c/csswg-drafts/issues/12513">Issue 12513</a>)
+	</li>
 	<li>Added a color-mix() example with three colors, now that it is no longer restricted to just two.</li>
 </ul>