Tweak visibility:collapse example to work properly.

Author: tabatkins

css3-flexbox/Overview.html

@@ -206,11 +206,11 @@
 
    <h1 id=head-box-flexible>CSS Flexible Box Layout Module</h1>
 
-   <h2 class="no-num no-toc" id=w3c-working>Editor's Draft, 19 July 2012</h2>
+   <h2 class="no-num no-toc" id=w3c-working>Editor's Draft, 20 July 2012</h2>
 
    <dl>
     <dt>This version:
-     <!--<dd><a href="http://www.w3.org/TR/2012/ED-css3-flexbox-20120719/">http://www.w3.org/TR/2012/WD-css3-flexbox-20120719/</a>-->
+     <!--<dd><a href="http://www.w3.org/TR/2012/ED-css3-flexbox-20120720/">http://www.w3.org/TR/2012/WD-css3-flexbox-20120720/</a>-->
 
 
     <dd><a
@@ -1098,11 +1098,16 @@ <h3 id=visibility-collapse><span class=secno>4.3. </span> Collapsed Items</h3>
 <!--		-->    #main {
 <!--		-->      flex: 1;         /* <a
     href="#flexibility">Main takes up all remaining space</a> */
-<!--		-->      order: 1         /* <a
-    href="#order-property">Place it after (to the right of) the navigation</a> */
 <!--		-->      min-width: 12em; /* <a
     href="#min-size-opt">Optimize main content area sizing</a> */
 <!--		-->    }
+<!--        -->    /* set up the menus as flexboxes so that visibility:collapse
+<!--        -->       will work properly */
+<!--        -->    nav > ul,
+<!--        -->    nav > ul > li { 
+<!--        -->      display: flex;
+<!--        -->      flex-flow: column;
+<!--        -->    }
 <!--		-->    /* dynamically collapse submenus when not targetted */
 <!--		-->    nav > ul > li:not(:target):not(:hover) > ul {
 <!--		-->      visibility: collapse;

css3-flexbox/Overview.src.html

@@ -771,9 +771,15 @@ <h3 id='visibility-collapse'>
 <!--		-->    header + div { display: flex; }
 <!--		-->    #main {
 <!--		-->      flex: 1;         /* <a href="#flexibility">Main takes up all remaining space</a> */
-<!--		-->      order: 1         /* <a href="#order-property">Place it after (to the right of) the navigation</a> */
 <!--		-->      min-width: 12em; /* <a href="#min-size-opt">Optimize main content area sizing</a> */
 <!--		-->    }
+<!--        -->    /* set up the menus as flexboxes so that visibility:collapse
+<!--        -->       will work properly */
+<!--        -->    nav > ul,
+<!--        -->    nav > ul > li { 
+<!--        -->      display: flex;
+<!--        -->      flex-flow: column;
+<!--        -->    }
 <!--		-->    /* dynamically collapse submenus when not targetted */
 <!--		-->    nav > ul > li:not(:target):not(:hover) > ul {
 <!--		-->      visibility: collapse;