diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 83ea59c..be075c6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,5 +14,9 @@ jobs:
         with:
           ruby-version: "3.3"
           bundler-cache: true
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "22"
+          cache: npm
       - run: bin/check_unicode
       - run: bin/build
diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
index d849ce7..a664332 100644
--- a/.github/workflows/deploy.yml
+++ b/.github/workflows/deploy.yml
@@ -26,6 +26,10 @@ jobs:
         with:
           ruby-version: "3.3"
           bundler-cache: true
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "22"
+          cache: npm
       - run: bin/build
       - uses: actions/configure-pages@v5
       - uses: actions/upload-pages-artifact@v3
diff --git a/.gitignore b/.gitignore
index d1d00dd..587667a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,6 +6,9 @@ _site/
 # Bundler
 vendor/
 
+# Node.js build dependencies
+node_modules/
+
 # macOS-specific files
 .DS_Store
 
diff --git a/README.md b/README.md
index be39890..643c434 100644
--- a/README.md
+++ b/README.md
@@ -6,6 +6,7 @@ Personal portfolio and blog built with [Jekyll](https://jekyllrb.com/).
 
 ```sh
 bundle install
+npm install
 ```
 
 ## Run
@@ -25,6 +26,7 @@ bin/build
 ```
 
 Builds the site and generates a PDF for each blog article with Chrome 131 or newer.
+Math is rendered to inline SVG with MathJax during the build, so Node.js 22 or newer is required.
 Set `BROWSER_PATH` if Chrome or Chromium is installed in a nonstandard location.
 
 ## License
diff --git a/_config.yml b/_config.yml
index 1263167..8b9391e 100644
--- a/_config.yml
+++ b/_config.yml
@@ -42,5 +42,8 @@ plugins:
 exclude:
   - Gemfile
   - Gemfile.lock
+  - node_modules/
+  - package-lock.json
+  - package.json
   - bin/
   - design.md
diff --git a/_layouts/base.html b/_layouts/base.html
index 48f5ee6..a8c3626 100644
--- a/_layouts/base.html
+++ b/_layouts/base.html
@@ -117,17 +117,47 @@
       }
       blockquote { margin: 1.2em 2em; font-style: italic; }
 
+      {%- if page.math %}
       /* Keep wide display math inside the article instead of widening the page. */
-      .katex-display {
+      mjx-container[jax="SVG"][display="true"] {
         max-width: 100%;
         overflow-x: auto;
         overflow-y: hidden;
       }
 
-      .katex-display > .katex {
-        max-width: none;
+      /* Select each path-only formula atomically and copy its TeX source. */
+      mjx-container[jax="SVG"] {
+        cursor: text;
+        user-select: all;
+        -webkit-user-select: all;
       }
 
+      mjx-container[jax="SVG"] .math-tex-source {
+        position: absolute;
+        width: 1px;
+        height: 1px;
+        overflow: hidden;
+        clip: rect(0, 0, 0, 0);
+        clip-path: inset(50%);
+        white-space: nowrap;
+      }
+
+      mjx-container[jax="SVG"].math-tex-selected {
+        background: Highlight;
+        color: HighlightText;
+      }
+
+      mjx-container[jax="SVG"][display="true"].math-tex-selected {
+        background: transparent;
+        color: inherit;
+      }
+
+      mjx-container[jax="SVG"][display="true"].math-tex-selected > svg {
+        background: Highlight;
+        color: HighlightText;
+      }
+      {%- endif %}
+
       /* Allow long URLs and inline code to wrap before widening the viewport. */
       main a,
       main code {
@@ -197,11 +227,6 @@
         thead { border-color: currentColor; }
       }
     </style>
-    {%- if page.math -%}
-    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.16.21/dist/katex.min.css" crossorigin="anonymous">
-    <script defer src="https://cdn.jsdelivr.net/npm/katex@0.16.21/dist/katex.min.js" crossorigin="anonymous"></script>
-    <script defer src="https://cdn.jsdelivr.net/npm/katex@0.16.21/dist/contrib/auto-render.min.js" crossorigin="anonymous" onload="renderMathInElement(document.body, {delimiters: [{left: '$$', right: '$$', display: true}, {left: '\\[', right: '\\]', display: true}, {left: '$', right: '$', display: false}, {left: '\\(', right: '\\)', display: false}]});"></script>
-    {%- endif -%}
   </head>
   <body>
     <div class="wrapper">
@@ -261,6 +286,9 @@
         <p><small>AI disclosure: The ideas, observations, and memories are mine. I write them down. I compress them. <a href="https://claude.ai/new">Claude</a> helps with language, wording, and clarity.</small></p>
       </footer>
     </div>
+    {%- if page.math %}
+    <script>document.addEventListener('selectionchange',()=>{const s=document.getSelection();document.querySelectorAll('mjx-container[jax="SVG"]').forEach(m=>m.classList.toggle('math-tex-selected',s&&!s.isCollapsed&&s.containsNode(m,true)));});</script>
+    {%- endif %}
     <script>document.querySelectorAll('main :is(h2,h3,h4,h5,h6)[id]').forEach(h=>h.innerHTML=`<a href="#${h.id}">${h.innerHTML}</a>`);</script>
     <script>document.addEventListener('keydown',e=>{const as=[...document.querySelectorAll('[aria-label="Post navigation"] a')];if(e.key==='ArrowLeft'){const a=as.find(a=>a.textContent.includes('<'));if(a)location.href=a.href;}if(e.key==='ArrowRight'){const a=as.find(a=>a.textContent.includes('>'));if(a)location.href=a.href;}});</script>
   </body>
diff --git a/_plugins/build_time_math.rb b/_plugins/build_time_math.rb
new file mode 100644
index 0000000..8fb6482
--- /dev/null
+++ b/_plugins/build_time_math.rb
@@ -0,0 +1,44 @@
+require "open3"
+
+module BuildTimeMath
+  DELIMITERS = /\$\$.*?\$\$|\$(?:\\.|[^$])+?\$|\\\(.*?\\\)|\\\[.*?\\\]/m
+
+  def self.render_html(html, site:, label:, fragment: false)
+    return html unless html.match?(DELIMITERS)
+
+    script = File.join(site.source, "bin", "render-math-svg.mjs")
+    command = ["node", script]
+    command << "--fragment" if fragment
+    output, errors, status = Open3.capture3(*command, stdin_data: html)
+
+    unless status.success?
+      raise Jekyll::Errors::FatalException,
+        "Math SVG rendering failed for #{label}:\n#{errors}"
+    end
+
+    output
+  end
+
+  def self.render(page)
+    return unless page.data["math"]
+
+    page.output = render_html(page.output, site: page.site, label: page.path)
+  end
+end
+
+module BuildTimeMathFilter
+  def render_math_svg(html)
+    site = @context.registers[:site]
+    BuildTimeMath.render_html(html, site: site, label: "RSS item", fragment: true)
+  end
+end
+
+Liquid::Template.register_filter(BuildTimeMathFilter)
+
+Jekyll::Hooks.register :pages, :post_render do |page|
+  BuildTimeMath.render(page)
+end
+
+Jekyll::Hooks.register :documents, :post_render do |document|
+  BuildTimeMath.render(document)
+end
diff --git a/assets/blog/lean_numberline_two_cases.svg b/assets/blog/lean_numberline_two_cases.svg
index e0fdbc8..345208c 100644
--- a/assets/blog/lean_numberline_two_cases.svg
+++ b/assets/blog/lean_numberline_two_cases.svg
@@ -7,6 +7,12 @@
     .tick { stroke: #181818; stroke-width: 1.4; }
     .brace{ stroke: #181818; stroke-width: 1.4; fill: none; }
     .dot  { fill: #181818; }
+
+    @media (prefers-color-scheme: dark) {
+      :root { fill: #fff; }
+      .ax, .tick, .brace { stroke: #fff; }
+      .dot, marker path { fill: #fff; }
+    }
   </style>
 
   <defs>
diff --git a/bin/build b/bin/build
index c27df72..4906a07 100755
--- a/bin/build
+++ b/bin/build
@@ -1,4 +1,5 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
+npm ci
 GENERATE_PDFS=1 bundle exec jekyll build "$@"
diff --git a/bin/render-math-svg.mjs b/bin/render-math-svg.mjs
new file mode 100644
index 0000000..8e174ef
--- /dev/null
+++ b/bin/render-math-svg.mjs
@@ -0,0 +1,104 @@
+#!/usr/bin/env node
+
+import { readFileSync } from "node:fs";
+import { mathjax } from "@mathjax/src/js/mathjax.js";
+import { TeX } from "@mathjax/src/js/input/tex.js";
+import { SVG } from "@mathjax/src/js/output/svg.js";
+import { liteAdaptor } from "@mathjax/src/js/adaptors/liteAdaptor.js";
+import { RegisterHTMLHandler } from "@mathjax/src/js/handlers/html.js";
+import { AssistiveMmlHandler } from "@mathjax/src/js/a11y/assistive-mml.js";
+import "@mathjax/src/js/util/asyncLoad/esm.js";
+
+import "@mathjax/src/js/input/tex/base/BaseConfiguration.js";
+import "@mathjax/src/js/input/tex/ams/AmsConfiguration.js";
+import "@mathjax/src/js/input/tex/color/ColorConfiguration.js";
+import "@mathjax/src/js/input/tex/newcommand/NewcommandConfiguration.js";
+import "@mathjax/src/js/input/tex/textmacros/TextMacrosConfiguration.js";
+
+const EM = 15;
+const EX = 7.5;
+const fragment = process.argv.includes("--fragment");
+const adaptor = liteAdaptor({ fontSize: EM });
+
+AssistiveMmlHandler(RegisterHTMLHandler(adaptor));
+
+const tex = new TeX({
+  packages: ["base", "ams", "color", "newcommand", "textmacros"],
+  inlineMath: [["$", "$"], ["\\(", "\\)"]],
+  displayMath: [["$$", "$$"], ["\\[", "\\]"]],
+  processEscapes: true,
+  formatError(jax, error) {
+    throw error;
+  }
+});
+const svg = new SVG({
+  exFactor: EX / EM,
+  fontCache: "none",
+  linebreaks: { inline: false }
+});
+const document = mathjax.document(readFileSync(0, "utf8"), {
+  InputJax: tex,
+  OutputJax: svg
+});
+
+await document.renderPromise();
+
+const root = adaptor.root(document.document);
+const errors = adaptor.tags(root, "g")
+  .filter((node) => adaptor.getAttribute(node, "data-mml-node") === "merror");
+if (errors.length > 0) {
+  const messages = errors.map((node) => adaptor.getAttribute(node, "data-mjx-error"));
+  throw new Error(`MathJax could not render:\n${messages.join("\n")}`);
+}
+
+for (const container of adaptor.tags(root, "mjx-container")) {
+  const math = adaptor.tags(container, "g")
+    .find((node) => adaptor.getAttribute(node, "data-mml-node") === "math");
+  const source = math && adaptor.getAttribute(math, "data-latex");
+  if (!source) continue;
+
+  if (fragment) {
+    const graphic = adaptor.tags(container, "svg")[0];
+    if (!graphic) continue;
+
+    const display = adaptor.getAttribute(container, "display") === "true";
+    const graphicStyle = adaptor.getAttribute(graphic, "style") || "";
+    const width = adaptor.getAttribute(graphic, "width");
+    const height = adaptor.getAttribute(graphic, "height");
+    const layout = display
+      ? `display:block;margin:.7em auto;padding:0;border:0;max-width:100%;width:${width};height:auto;`
+      : `display:inline-block;margin:0;padding:0;border:0;max-width:none;width:${width};height:${height};`;
+    adaptor.setAttribute(graphic, "style", `${graphicStyle}${layout}`);
+    adaptor.setAttribute(graphic, "aria-label", source);
+    adaptor.removeAttribute(graphic, "aria-hidden");
+    adaptor.replace(graphic, container);
+    continue;
+  }
+
+  const selectableSource = source.replace(/\r?\n[\t ]*/g, " ");
+  const text = adaptor.node("span", {
+    "aria-hidden": "true",
+    class: "math-tex-source"
+  }, [adaptor.text(selectableSource)]);
+  adaptor.append(container, text);
+}
+
+for (const background of adaptor.tags(root, "rect")) {
+  if (adaptor.getAttribute(background, "data-bgcolor") !== "true") continue;
+
+  const content = adaptor.next(background);
+  if (content && adaptor.kind(content) === "g") {
+    adaptor.setAttribute(content, "fill", "#1c1c1a");
+    adaptor.setAttribute(content, "stroke", "#1c1c1a");
+  }
+}
+
+const html = adaptor.outerHTML(root)
+  .replace(/@font-face \/\* zero \*\/ \{[\s\S]*?\n\}/, "");
+
+if (fragment) {
+  process.stdout.write(adaptor.innerHTML(adaptor.body(document.document)));
+} else {
+  process.stdout.write(adaptor.doctype(document.document));
+  process.stdout.write(html);
+}
diff --git a/package-lock.json b/package-lock.json
new file mode 100644
index 0000000..f456b53
--- /dev/null
+++ b/package-lock.json
@@ -0,0 +1,198 @@
+{
+  "name": "build-time-katex",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "dependencies": {
+        "@mathjax/src": "4.1.3"
+      },
+      "engines": {
+        "node": ">=22"
+      }
+    },
+    "node_modules/@mathjax/src": {
+      "version": "4.1.3",
+      "resolved": "https://registry.npmjs.org/@mathjax/src/-/src-4.1.3.tgz",
+      "integrity": "sha512-rIrWquuBSoJuoMBdC/1qD+AUHTorlccPicoVy6P2xbUgnuDBpCcpbHtOAsB8L3hdCHtNBg92lF8e3Fz+pkcQbw==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "@mathjax/mathjax-newcm-font": "4.1.3",
+        "mhchemparser": "^4.2.1",
+        "mj-context-menu": "^1.0.0",
+        "speech-rule-engine": "5.0.0-rc.4"
+      }
+    },
+    "node_modules/@mathjax/src/node_modules/@mathjax/mathjax-newcm-font": {
+      "version": "4.1.3",
+      "resolved": "https://registry.npmjs.org/@mathjax/mathjax-newcm-font/-/mathjax-newcm-font-4.1.3.tgz",
+      "integrity": "sha512-gzAB3dFHilHX1l5x2xUqRL+1jDQt3Fyza1DkEMVXWC4E8SvsGdlgEza47HYi2WhVcgfkvf4zgUGzuhbq3Pjlew==",
+      "license": "Apache-2.0"
+    },
+    "node_modules/@xmldom/xmldom": {
+      "version": "0.9.12",
+      "resolved": "https://registry.npmjs.org/@xmldom/xmldom/-/xmldom-0.9.12.tgz",
+      "integrity": "sha512-5AXjrcMClTryPe9LgZrygpB1lj7s0S9E0+W+AHaVKAVyHanafK86iPSvG5xHVSp/jC+VH1UXu0TAEmY279xH7A==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=14.6"
+      }
+    },
+    "node_modules/balanced-match": {
+      "version": "4.0.4",
+      "resolved": "https://registry.npmjs.org/balanced-match/-/balanced-match-4.0.4.tgz",
+      "integrity": "sha512-BLrgEcRTwX2o6gGxGOCNyMvGSp35YofuYzw9h1IMTRmKqttAZZVU67bdb9Pr2vUHA8+j3i2tJfjO6C6+4myGTA==",
+      "license": "MIT",
+      "engines": {
+        "node": "18 || 20 || >=22"
+      }
+    },
+    "node_modules/brace-expansion": {
+      "version": "5.0.12",
+      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-5.0.12.tgz",
+      "integrity": "sha512-YovQ3rzhaLMIrDjNDMkNS01tea93qhEhG5xy8f6+R0l+dw3Ki+5sCoIoI942iuLZTHWogWktgwVDhU09iNEimQ==",
+      "license": "MIT",
+      "dependencies": {
+        "balanced-match": "^4.0.2"
+      },
+      "engines": {
+        "node": "20 || >=22"
+      }
+    },
+    "node_modules/commander": {
+      "version": "14.0.3",
+      "resolved": "https://registry.npmjs.org/commander/-/commander-14.0.3.tgz",
+      "integrity": "sha512-H+y0Jo/T1RZ9qPP4Eh1pkcQcLRglraJaSLoyOtHxu6AapkjWVCy2Sit1QQ4x3Dng8qDlSsZEet7g5Pq06MvTgw==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=20"
+      }
+    },
+    "node_modules/glob": {
+      "version": "13.0.6",
+      "resolved": "https://registry.npmjs.org/glob/-/glob-13.0.6.tgz",
+      "integrity": "sha512-Wjlyrolmm8uDpm/ogGyXZXb1Z+Ca2B8NbJwqBVg0axK9GbBeoS7yGV6vjXnYdGm6X53iehEuxxbyiKp8QmN4Vw==",
+      "license": "BlueOak-1.0.0",
+      "dependencies": {
+        "minimatch": "^10.2.2",
+        "minipass": "^7.1.3",
+        "path-scurry": "^2.0.2"
+      },
+      "engines": {
+        "node": "18 || 20 || >=22"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/isaacs"
+      }
+    },
+    "node_modules/mhchemparser": {
+      "version": "4.2.1",
+      "resolved": "https://registry.npmjs.org/mhchemparser/-/mhchemparser-4.2.1.tgz",
+      "integrity": "sha512-kYmyrCirqJf3zZ9t/0wGgRZ4/ZJw//VwaRVGA75C4nhE60vtnIzhl9J9ndkX/h6hxSN7pjg/cE0VxbnNM+bnDQ==",
+      "license": "Apache-2.0"
+    },
+    "node_modules/minimatch": {
+      "version": "10.2.6",
+      "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-10.2.6.tgz",
+      "integrity": "sha512-vpLQEs+VLCr1nU0BXS07maYoFwlDAH0gngQuuttxIwutDFEMHq2blX+8vpgxDdK3J1PwjCJiep77OitTZ4Ll1A==",
+      "license": "BlueOak-1.0.0",
+      "dependencies": {
+        "brace-expansion": "^5.0.8"
+      },
+      "engines": {
+        "node": "18 || 20 || >=22"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/isaacs"
+      }
+    },
+    "node_modules/minipass": {
+      "version": "7.1.3",
+      "resolved": "https://registry.npmjs.org/minipass/-/minipass-7.1.3.tgz",
+      "integrity": "sha512-tEBHqDnIoM/1rXME1zgka9g6Q2lcoCkxHLuc7ODJ5BxbP5d4c2Z5cGgtXAku59200Cx7diuHTOYfSBD8n6mm8A==",
+      "license": "BlueOak-1.0.0",
+      "engines": {
+        "node": ">=16 || 14 >=14.17"
+      }
+    },
+    "node_modules/mj-context-menu": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/mj-context-menu/-/mj-context-menu-1.0.0.tgz",
+      "integrity": "sha512-OSgBFQRCVhrZwRa9lhqnKcJU92dd/YXgBjup0uyeuj9bOaVsf4myOyrjU4PfhYkdDk6AqVUTov7v5uFMvIbduA==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "rimraf": "^6.0.1"
+      }
+    },
+    "node_modules/package-json-from-dist": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/package-json-from-dist/-/package-json-from-dist-1.0.1.tgz",
+      "integrity": "sha512-UEZIS3/by4OC8vL3P2dTXRETpebLI2NiI5vIrjaD/5UtrkFX/tNbwjTSRAGC/+7CAo2pIcBaRgWmcBBHcsaCIw==",
+      "license": "BlueOak-1.0.0"
+    },
+    "node_modules/path-scurry": {
+      "version": "2.0.2",
+      "resolved": "https://registry.npmjs.org/path-scurry/-/path-scurry-2.0.2.tgz",
+      "integrity": "sha512-3O/iVVsJAPsOnpwWIeD+d6z/7PmqApyQePUtCndjatj/9I5LylHvt5qluFaBT3I5h3r1ejfR056c+FCv+NnNXg==",
+      "license": "BlueOak-1.0.0",
+      "dependencies": {
+        "lru-cache": "^11.0.0",
+        "minipass": "^7.1.2"
+      },
+      "engines": {
+        "node": "18 || 20 || >=22"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/isaacs"
+      }
+    },
+    "node_modules/path-scurry/node_modules/lru-cache": {
+      "version": "11.5.2",
+      "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-11.5.2.tgz",
+      "integrity": "sha512-4pfM1Ff0x50o0tQwb5ucw/RzNyD0/YJME6IVcStalZuMWxdt3sR3huStTtxz4PUmvZfRguvDejasvQ2kifR11g==",
+      "license": "BlueOak-1.0.0",
+      "engines": {
+        "node": "20 || >=22"
+      }
+    },
+    "node_modules/rimraf": {
+      "version": "6.1.3",
+      "resolved": "https://registry.npmjs.org/rimraf/-/rimraf-6.1.3.tgz",
+      "integrity": "sha512-LKg+Cr2ZF61fkcaK1UdkH2yEBBKnYjTyWzTJT6KNPcSPaiT7HSdhtMXQuN5wkTX0Xu72KQ1l8S42rlmexS2hSA==",
+      "license": "BlueOak-1.0.0",
+      "dependencies": {
+        "glob": "^13.0.3",
+        "package-json-from-dist": "^1.0.1"
+      },
+      "bin": {
+        "rimraf": "dist/esm/bin.mjs"
+      },
+      "engines": {
+        "node": "20 || >=22"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/isaacs"
+      }
+    },
+    "node_modules/speech-rule-engine": {
+      "version": "5.0.0-rc.4",
+      "resolved": "https://registry.npmjs.org/speech-rule-engine/-/speech-rule-engine-5.0.0-rc.4.tgz",
+      "integrity": "sha512-3dFcH2QtQNhtvUUc09TxoaEK4WG03B9Z57krFG9jocrKykKGu35BhIkWr0vgEAxZZomEWkeluff69y/EbYzP4Q==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "@xmldom/xmldom": "^0.9.10",
+        "commander": "^14.0.3",
+        "wicked-good-xpath": "^1.3.0"
+      },
+      "bin": {
+        "sre": "bin/sre"
+      }
+    },
+    "node_modules/wicked-good-xpath": {
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/wicked-good-xpath/-/wicked-good-xpath-1.3.0.tgz",
+      "integrity": "sha512-Gd9+TUn5nXdwj/hFsPVx5cuHHiF5Bwuc30jZ4+ronF1qHK5O7HD0sgmXWSEgwKquT3ClLoKPVbO6qGwVwLzvAw==",
+      "license": "MIT"
+    }
+  }
+}
diff --git a/package.json b/package.json
new file mode 100644
index 0000000..8d434de
--- /dev/null
+++ b/package.json
@@ -0,0 +1,9 @@
+{
+  "private": true,
+  "engines": {
+    "node": ">=22"
+  },
+  "dependencies": {
+    "@mathjax/src": "4.1.3"
+  }
+}
diff --git a/rss.xml b/rss.xml
index 12c4c46..62ace86 100644
--- a/rss.xml
+++ b/rss.xml
@@ -17,11 +17,12 @@ permalink: /rss.xml
     {%- for post in site.posts %}
     {%- assign feedback_target = site.url | append: post.url %}
     {%- capture feedback_link %}<hr><p><a href="{{ feedback_form }}{{ feedback_target | url_encode }}" target="_blank" rel="noopener noreferrer">Challenge this post (anonymous)</a></p>{% endcapture %}
+    {%- assign description = post.content | append: feedback_link | render_math_svg %}
     <item>
       <title>{{ post.title | xml_escape }}</title>
       <link>{{ site.url }}{{ post.url }}</link>
       <guid>{{ site.url }}{{ post.url }}</guid>
-      <description>{{ post.content | append: feedback_link | xml_escape }}</description>
+      <description>{{ description | xml_escape }}</description>
       <pubDate>{{ post.date | date_to_rfc822 }}</pubDate>
       {%- for tag in post.tags %}
       <category>{{ tag | xml_escape }}</category>
@@ -34,11 +35,12 @@ permalink: /rss.xml
     {%- assign slug = entry.title | replace: ".", "" | slugify %}
     {%- assign feedback_target = site.url | append: "/threads/#" | append: slug %}
     {%- capture feedback_link %}<hr><p><a href="{{ feedback_form }}{{ feedback_target | url_encode }}" target="_blank" rel="noopener noreferrer">Challenge this thread (anonymous)</a></p>{% endcapture %}
+    {%- assign description = entry.content | append: feedback_link | render_math_svg %}
     <item>
       <title>Threads: {{ entry.title | xml_escape }}</title>
       <link>{{ site.url }}/threads/#{{ slug }}</link>
       <guid isPermaLink="false">{{ site.url }}/threads/#{{ slug }}</guid>
-      <description><![CDATA[{{ entry.content }}{{ feedback_link }}]]></description>
+      <description><![CDATA[{{ description }}]]></description>
       <pubDate>{{ entry.date | date_to_rfc822 }}</pubDate>
       <category>threads</category>
     </item>
@@ -46,11 +48,12 @@ permalink: /rss.xml
     {%- for project in site.projects %}
     {%- assign feedback_target = site.url | append: project.url %}
     {%- capture feedback_link %}<hr><p><a href="{{ feedback_form }}{{ feedback_target | url_encode }}" target="_blank" rel="noopener noreferrer">Challenge this project (anonymous)</a></p>{% endcapture %}
+    {%- assign description = project.content | markdownify | replace: 'src="/', 'src="https://cb341.dev/' | replace: 'href="/', 'href="https://cb341.dev/' | append: feedback_link | render_math_svg %}
     <item>
       <title>Project: {{ project.title | xml_escape }}</title>
       <link>{{ site.url }}{{ project.url }}</link>
       <guid isPermaLink="false">{{ site.url }}{{ project.url }}</guid>
-      <description><![CDATA[{{ project.content | markdownify | replace: 'src="/', 'src="https://cb341.dev/' | replace: 'href="/', 'href="https://cb341.dev/' }}{{ feedback_link }}]]></description>
+      <description><![CDATA[{{ description }}]]></description>
       <pubDate>{{ project.date | date_to_rfc822 }}</pubDate>
       <category>project</category>
       {%- for tag in project.tags %}