diff --git a/Cyjb.Markdown/ParseBlock/HtmlInfo.cs b/Cyjb.Markdown/ParseBlock/HtmlInfo.cs
index 5823ade..7269474 100644
--- a/Cyjb.Markdown/ParseBlock/HtmlInfo.cs
+++ b/Cyjb.Markdown/ParseBlock/HtmlInfo.cs
@@ -22,34 +22,34 @@ internal sealed class HtmlInfo
 			{
 				case 5:
 					// </pre>
-					return char.ToLowerInvariant(sb[index + 2]) == 'p' &&
-						   char.ToLowerInvariant(sb[index + 3]) == 'r' &&
-						   char.ToLowerInvariant(sb[index + 4]) == 'e';
+					return (sb[index + 2] is 'p' or 'P') &&
+						   (sb[index + 3] is 'r' or 'R') &&
+						   (sb[index + 4] is 'e' or 'E');
 				case 7:
 					// </style>
-					return char.ToLowerInvariant(sb[index + 2]) == 's' &&
-						   char.ToLowerInvariant(sb[index + 3]) == 't' &&
-						   char.ToLowerInvariant(sb[index + 4]) == 'y' &&
-						   char.ToLowerInvariant(sb[index + 5]) == 'l' &&
-						   char.ToLowerInvariant(sb[index + 6]) == 'e';
+					return (sb[index + 2] is 's' or 'S') &&
+						   (sb[index + 3] is 't' or 'T') &&
+						   (sb[index + 4] is 'y' or 'Y') &&
+						   (sb[index + 5] is 'l' or 'L') &&
+						   (sb[index + 6] is 'e' or 'E');
 				case 8:
 					// </script>
-					return char.ToLowerInvariant(sb[index + 2]) == 's' &&
-						   char.ToLowerInvariant(sb[index + 3]) == 'c' &&
-						   char.ToLowerInvariant(sb[index + 4]) == 'r' &&
-						   char.ToLowerInvariant(sb[index + 5]) == 'i' &&
-						   char.ToLowerInvariant(sb[index + 6]) == 'p' &&
-						   char.ToLowerInvariant(sb[index + 7]) == 't';
+					return (sb[index + 2] is 's' or 'S') &&
+						   (sb[index + 3] is 'c' or 'C') &&
+						   (sb[index + 4] is 'r' or 'R') &&
+						   (sb[index + 5] is 'i' or 'I') &&
+						   (sb[index + 6] is 'p' or 'P') &&
+						   (sb[index + 7] is 't' or 'T');
 				case 10:
 					// </textarea>
-					return char.ToLowerInvariant(sb[index + 2]) == 't' &&
-						   char.ToLowerInvariant(sb[index + 3]) == 'e' &&
-						   char.ToLowerInvariant(sb[index + 4]) == 'x' &&
-						   char.ToLowerInvariant(sb[index + 5]) == 't' &&
-						   char.ToLowerInvariant(sb[index + 6]) == 'a' &&
-						   char.ToLowerInvariant(sb[index + 7]) == 'r' &&
-						   char.ToLowerInvariant(sb[index + 8]) == 'e' &&
-						   char.ToLowerInvariant(sb[index + 9]) == 'a';
+					return (sb[index + 2] is 't' or 'T') &&
+						   (sb[index + 3] is 'e' or 'E') &&
+						   (sb[index + 4] is 'x' or 'X') &&
+						   (sb[index + 5] is 't' or 'T') &&
+						   (sb[index + 6] is 'a' or 'A') &&
+						   (sb[index + 7] is 'r' or 'R') &&
+						   (sb[index + 8] is 'e' or 'E') &&
+						   (sb[index + 9] is 'a' or 'A');
 			}
 			index = sb.IndexOf("</", index + 2);
 		}