いい感じにやった

src/common/text/elements/code.js

@@ -188,6 +188,16 @@ const elements = [
 		};
 	},
 
+	// label
+	code => {
+		if (code[0] != '@') return null;
+		const label = code.match(/^@([a-zA-Z_-]+?)\n/)[0];
+		return {
+			html: `<span class="label">${label}</span>`,
+			next: label.length
+		};
+	},
+
 	// extract vars
 	(code, i, source, vars) => {
 		const prev = source[i - 1];

src/web/app/base.styl

@@ -107,7 +107,10 @@ a
 	*
 		cursor pointer
 
-pre > code
+pre
+	overflow auto
+
+	> code
 		font-family Consolas, 'Courier New', Courier, Monaco, monospace
 		tab-size 2
 
@@ -148,6 +151,9 @@ pre > code
 		.property
 			color #a71d5d
 
+		.label
+			color #e9003f
+
 mk-locker
 	display block
 	position fixed

src/web/app/desktop/tags/timeline-post-sub.tag

@@ -91,9 +91,9 @@
 							font-size 1.1em
 							color #717171
 
-			
+							pre
-
+								max-height 120px
-			
+								font-size 80%
 
 	</style>
 </mk-timeline-post-sub>

src/web/app/desktop/tags/timeline-post.tag

@@ -233,7 +233,6 @@
 
 							pre
 								padding 16px
-								overflow auto
 								font-size 80%
 								color #525252
 								background #f8f8f8

src/web/app/mobile/tags/timeline-post-sub.tag

@@ -91,6 +91,10 @@
 							font-size 1.1em
 							color #717171
 
+							pre
+								max-height 120px
+								font-size 80%
+
 	</style>
 	<script>@post = @opts.post</script>
 </mk-timeline-post-sub>

src/web/app/mobile/tags/timeline-post.tag

@@ -212,7 +212,6 @@
 
 							pre
 								padding 16px
-								overflow auto
 								font-size 80%
 								color #525252
 								background #f8f8f8