change bottom right positioning offset example to use new syntax

Author: fantasai

css3-background/Overview.html

@@ -1097,13 +1097,11 @@ <h3 id=the-background-position><span class=secno>3.6 </span>The
   </div>
 
   <div class=example>
-   <p>With the &lsquo;<code class=css>calc()</code>&rsquo; notation from the
-    Values and Units module <a href="#CSS3VAL"
-    rel=biblioentry>[CSS3VAL]<!--{{CSS3VAL}}--></a>, background positions can
-    also be relative to other corners than the top left. E.g., the following
-    puts the background image 10px from the bottom and 3em from the right:
+   <p>Background positions can also be relative to other corners than the top
+    left. E.g., the following puts the background image 10px from the bottom
+    and 3em from the right:
 
-   <pre>background-position: calc(100% - 3em) calc(100% - 10px)</pre>
+   <pre>background-position: right 3em bottom 10px</pre>
   </div>
 
   <p>See the section <a href="#layering">“Layering multiple background
@@ -3855,16 +3853,6 @@ <h3 class=no-num id=other>Other references</h3>
     W3C Working Draft. (Work in progress.)</dd>
    <!---->
 
-   <dt id=CSS3VAL>[CSS3VAL]
-
-   <dd>H&#229;kon Wium Lie; Chris Lilley. <a
-    href="http://www.w3.org/TR/2006/WD-css3-values-20060919"><cite>CSS3
-    Values and Units.</cite></a> 19 September 2006. W3C Working Draft. (Work
-    in progress.) URL: <a
-    href="http://www.w3.org/TR/2006/WD-css3-values-20060919">http://www.w3.org/TR/2006/WD-css3-values-20060919</a>
-    </dd>
-   <!---->
-
    <dt id=RFC2854>[RFC2854]
 
    <dd>D. Connolly; L. Masinter. <a

css3-background/Overview.src.html

@@ -758,12 +758,11 @@ <h3>The 'background-position' property</h3>
 </div>
 
 <div class=example>
-<p>With the 'calc()' notation from the Values and Units module
-[[CSS3VAL]], background positions can also be relative to other
-corners than the top left. E.g., the following puts the background
-image 10px from the bottom and 3em from the right:
+<p>Background positions can also be relative to other corners than the
+top left. E.g., the following puts the background image 10px from the
+bottom and 3em from the right:
 
-<pre>background-position: calc(100% - 3em) calc(100% - 10px)</pre>
+<pre>background-position: right 3em bottom 10px</pre>
 </div>
 
 <p>See the section <a href="#layering">“Layering multiple background