[css-text] Tweak example styling

Author: frivoal

css-text-3/Overview.bs

@@ -134,18 +134,6 @@ spec:css-ruby-1; type:dfn; text:ruby
 	.ls-ex .letter.ls2 { padding: 0 1em 0 1em; }
 	.ls-ex .letter.first { padding-left: 0; }
 	.ls-ex .letter.last { padding-right: 0; }
-	.ls-ex .letter.ls2::after {
-		margin-right: 1em;
-		margin-left: 1em;
-		left: 0;
-		right: 0;
-		top: 0;
-		border-right: 1px solid black;
-		border-left: 1px solid black;
-		content: "";
-		position: absolute;
-		height: 5px;
-	}
 	.ls-ex .letter::after {
 		left: 0;
 		right: 0;
@@ -156,13 +144,13 @@ spec:css-ruby-1; type:dfn; text:ruby
 		position: absolute;
 		height: 5px;
 	}
-	.ls-ex .letter.ls1::after {
-		margin-right: 0.5em;
-		margin-left: 0.5em;
-	}
 	.ls-ex .letter.ls2::after {
-		margin-right: 1em;
-		margin-left: 1em;
+		margin-right: calc(1em + 0.5px);
+		margin-left: calc(1em + 0.5px);
+	}
+	.ls-ex .letter.ls1::after {
+		margin-right: calc(0.5em + 0.5px);
+		margin-left: calc(0.5em + 0.5px);
 	}
 	.ls-ex .letter.last::after {
 		border-right: none;

css-text-4/Overview.bs

@@ -146,18 +146,6 @@ spec:selectors-4; type:dfn; text:selector
 	.ls-ex .letter.ls2 { padding: 0 1em 0 1em; }
 	.ls-ex .letter.first { padding-left: 0; }
 	.ls-ex .letter.last { padding-right: 0; }
-	.ls-ex .letter.ls2::after {
-		margin-right: 1em;
-		margin-left: 1em;
-		left: 0;
-		right: 0;
-		top: 0;
-		border-right: 1px solid black;
-		border-left: 1px solid black;
-		content: "";
-		position: absolute;
-		height: 5px;
-	}
 	.ls-ex .letter::after {
 		left: 0;
 		right: 0;
@@ -168,13 +156,13 @@ spec:selectors-4; type:dfn; text:selector
 		position: absolute;
 		height: 5px;
 	}
-	.ls-ex .letter.ls1::after {
-		margin-right: 0.5em;
-		margin-left: 0.5em;
-	}
 	.ls-ex .letter.ls2::after {
-		margin-right: 1em;
-		margin-left: 1em;
+		margin-right: calc(1em + 0.5px);
+		margin-left: calc(1em + 0.5px);
+	}
+	.ls-ex .letter.ls1::after {
+		margin-right: calc(0.5em + 0.5px);
+		margin-left: calc(0.5em + 0.5px);
 	}
 	.ls-ex .letter.last::after {
 		border-right: none;