diff --git a/src/content/metadata.json b/src/content/metadata.json
index fe4b596..258fb4b 100644
--- a/src/content/metadata.json
+++ b/src/content/metadata.json
@@ -12,5 +12,12 @@
 	},
 	"extra": [
 		{ "route": "/archives", "name": "Archives" }
-	]
+	],
+	"markdown": {
+		"highlighterLangs": [
+			"python",
+			"lean",
+			"tex"
+		]
+	}
 }
diff --git a/src/content/post/the-perfect-math-class.md b/src/content/post/the-perfect-math-class.md
index ce1e00e..d016784 100644
--- a/src/content/post/the-perfect-math-class.md
+++ b/src/content/post/the-perfect-math-class.md
@@ -26,3 +26,7 @@ $$
 $$
 \vec z^{(l+1)} = \mat M\vec z^{(l)} + \vec b
 $$
+
+```tex
+\\newcommand{\\cirno}{9}
+```
diff --git a/svelte.config.js b/svelte.config.js
index deabdb8..7fcd4df 100644
--- a/svelte.config.js
+++ b/svelte.config.js
@@ -1,5 +1,6 @@
 import { vitePreprocess } from '@sveltejs/vite-plugin-svelte';
 import adapter from '@sveltejs/adapter-static';
+import fs from 'fs';
 
 import { mdsvex, escapeSvelte } from 'mdsvex';
 import remarkAlert from './src/lib/markdown.js'
@@ -12,7 +13,9 @@ import remarkMath from 'remark-math'
 
 const contentDir = process.env?.CHRYSOBLOG_CONTENT ?? "src/content";
 
-const langs = [
+const metadata = await fs.promises.readFile(contentDir + "/metadata.json")
+                         .then((file) => JSON.parse(file.toString()));
+const langs = metadata?.markdown.highlighterLangs ?? [
    "javascript",
    "lean",
    "lisp",
@@ -26,11 +29,7 @@ const langs = [
    "c++",
    "sh",
 ];
-const highlightingThemes = {
-   light: 'vitesse-light',
-   dark: 'vitesse-dark',
-};
-const katexOptions = {
+const katexOptions = metadata?.markdown.katex ?? {
    macros: {
       "\\Nat": "\\mathbb N",
       "\\Complex": "\\mathbb C",
@@ -39,6 +38,10 @@ const katexOptions = {
       "\\rv": "\\mathrm",
    },
 };
+const highlightingThemes = {
+   light: 'vitesse-light',
+   dark: 'vitesse-dark',
+};
 
 const themes = Object.keys(highlightingThemes).map(function(k){ return highlightingThemes[k] });
 const highlighter = await getHighlighter({