[css-snappoints] Adding in detail of scroll-snap-padding

css-snappoints/Overview.src.html

@@ -228,7 +228,7 @@ <h2 id="scroll-snap-type">Scroll Snap Types: the 'scroll-snap-type' property</h2
 
 <h2 id="scroll-snap-padding">Scroll Snap Padding: the 'scroll-snap-padding' property</h2>
 
-    The 'scroll-snap-padding' property defines a region inset from the visual viewport of a <a>scroll container</a> used in calculating its <a>snap positions</a>.
+    The 'scroll-snap-padding' property defines the <a>snap viewport</a>, a region inset from the visual viewport of a <a>scroll container</a> used in calculating its <a>snap positions</a>.  The snap viewport is used as the alignment container when calculating valid <a>snap positions</a>.
 
     <pre class="propdef">
     Name: scroll-snap-padding
@@ -248,6 +248,8 @@ <h2 id="scroll-snap-padding">Scroll Snap Padding: the 'scroll-snap-padding' prop
             Specifies the region inset from the visual viewport.  Values are interpreted as for 'padding', and specify inward offsets from each edge of the visual viewport.
     </dl>
 
+    This property is a shorthand property that sets all of the 'scroll-snap-padding-*' longhands in one declaration.
+
 <h2 id="scroll-snap-area">Scroll Snap Area: the 'scroll-snap-area' property</h2>
 
     The 'scroll-snap-area' property defines a region for an element used in calculating <a>snap positions</a> for its ancestor scroll container.