[css-snap-size] Fix baseline formula

Author: kojiishi

css-snap-size/Overview.bs

@@ -35,7 +35,7 @@ Snapping Heights: the 'snap-height' property {#snap-height}
   Animatable: no
   Percentages: N/A
   Media: visual
-  Computed Value: as specified
+  Computed Value: length becomes the absolute length, others as specified
 </pre>
 
 Values have the following meanings:
@@ -126,8 +126,8 @@ Snapping Baselines {#snap-baseline}
 When the <a>grid baseline position</a> is a positive number equals to or less than 1,
 the additional spaces are distributed using the following formula:
 
-* space-over = GU - mod(T + GU - BP, GU)
-* space-under = GU - mod(space-over + T + B, GU)
+* space-over = (BP - T &amp; GU + GU) &amp; GU
+* space-under = GU - (space-over + T + B) &amp; GU
 * GU: the <a>grid unit</a>.
 * BP: the <a>grid baseline position</a> &times; GU / 100.
 * T: the distance between the top of the line box and the baseline.
@@ -148,12 +148,12 @@ as a consequence.
   </div>
 
   The following CSS sets the <a>grid baseline position</a>
-  to 16pt (20pt &times; .8) from the top.
+  to 16pt (20pt &times; 0.70) from the top.
 
   <pre class="lang-css">
   :root {
     --my-grid: 20pt;
-    snap-height: var(--my-grid) .7;
+    snap-height: var(--my-grid) 70;
   }
   </pre>
 
@@ -183,7 +183,7 @@ Snapping Widths: the 'snap-width' property {#snap-width}
   Animatable: no
   Percentages: N/A
   Media: visual
-  Computed Value: as specified
+  Computed Value: length becomes the absolute length, others as specified
 </pre>
 Values have the following meanings: