revising examples

Author: howcome

css-multicol/Overview.src.html

@@ -1692,11 +1692,10 @@ <h3>'column-span'</h3>
 <p>Spanners create new block formatting contexts, but their margins
 can be changed by their surroundings. In this example, two spanners
 naturally end up at the top of a page. The top margin of the first
-spanner is truncated due to being after an unforced break. The bottom
-margin of the first spanner collapses with the top margin of the
-second spanner. However, the bottom margin of the second spanner does
-not collabse with the collapses with the top margin of the subsequent
-element.
+spanner is truncated due to adjoining an unforced break. The margins
+between the two spanners collapse with each other. However, the bottom
+margin of the second spanner does not collapse with the top margin of
+the subsequent element.
 
 
 <pre class="css">
@@ -1705,14 +1704,15 @@ <h3>'column-span'</h3>
   column-span: all; 
   background: silver 
 } 
+p { margin-top: 1em }
 </pre>
 
 
-<div class=cols>
+<div class=cols style="border-top: none">
 
 <p><br><br><br><br>
 
-M nop qrst uv wx yz.<br>
+<br>
 Ab cde fgh i jkl. Mno<br> 
 pqr stu vw xyz. A bc<br>
 def g hij klm nopqrs<br>