[cssom] editorial: fix typo and clarify a bit

Author: Simon Pieters

cssom/Overview.html

@@ -2191,9 +2191,9 @@ <h3 id="css-declaration-blocks"><span class="secno">6.5 </span>CSS Declaration B
 
 <ol>
  <li><p>Order <var>shorthands</var> lexicographically.
- <li><p>Move all items in <var>shorthands</var> that begin with "<code title="">-</code>" (U+002D) last in the list.
- <li><p>Move all items in <var>shorthands</var> that begin with "<code title="">-</code>" (U+002D) but do no begin with "<code title="">-webkit-</code>" last in the
- list.
+ <li><p>Move all items in <var>shorthands</var> that begin with "<code title="">-</code>" (U+002D) last in the list, retaining their relative order.
+ <li><p>Move all items in <var>shorthands</var> that begin with "<code title="">-</code>" (U+002D) but do not begin with "<code title="">-webkit-</code>" last in the
+ list, retaining their relative order.
  <li><p>Order <var>shorthands</var> by the number of longhand properties that map to it, with the greatest number first.
 </ol>
 

cssom/Overview.src.html

@@ -2113,9 +2113,9 @@ <h3>CSS Declaration Blocks</h3>
 
 <ol>
  <li><p>Order <var>shorthands</var> lexicographically.
- <li><p>Move all items in <var>shorthands</var> that begin with "<code title>-</code>" (U+002D) last in the list.
- <li><p>Move all items in <var>shorthands</var> that begin with "<code title>-</code>" (U+002D) but do no begin with "<code title>-webkit-</code>" last in the
- list.
+ <li><p>Move all items in <var>shorthands</var> that begin with "<code title>-</code>" (U+002D) last in the list, retaining their relative order.
+ <li><p>Move all items in <var>shorthands</var> that begin with "<code title>-</code>" (U+002D) but do not begin with "<code title>-webkit-</code>" last in the
+ list, retaining their relative order.
  <li><p>Order <var>shorthands</var> by the number of longhand properties that map to it, with the greatest number first.
 </ol>