Use 'from' syntax from dbaron's original.

Author: fantasai

css3-images/Overview.html

@@ -862,7 +862,7 @@ <h4 class=no-toc id=radial-gradient-syntax><span class=secno>5.2.1. </span>
 <dfn
    id=ltradial-gradient>&lt;radial-gradient></dfn> = radial-gradient(
   [ [ &lt;shape&gt; , ] |
-    [ &lt;shape&gt;? [ at &lt;position&gt; || to &lt;extent&gt; ] , ]
+    [ &lt;shape&gt;? [ from &lt;position&gt; || to &lt;extent&gt; ] , ]
   ]?
   &lt;color-stop&gt; [ , &lt;color-stop&gt; ]+
 )</pre>

css3-images/Overview.src.html

@@ -550,7 +550,7 @@ <h4 class='no-toc' id='radial-gradient-syntax'>
 	<pre class=prod>
 <dfn>&lt;radial-gradient></dfn> = radial-gradient(
   [ [ &lt;shape&gt; , ] |
-    [ &lt;shape&gt;? [ at &lt;position&gt; || to &lt;extent&gt; ] , ]
+    [ &lt;shape&gt;? [ from &lt;position&gt; || to &lt;extent&gt; ] , ]
   ]?
   &lt;color-stop&gt; [ , &lt;color-stop&gt; ]+
 )</pre>