diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..58db40d
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+docs/index.html
+node_modules/
diff --git a/build.js b/build.js
new file mode 100644
index 0000000..af4746f
--- /dev/null
+++ b/build.js
@@ -0,0 +1,22 @@
+#!/usr/bin/env node
+const ejs = require("ejs");
+const fs = require("fs");
+
+let id = 0;
+function getNewId() {
+  return ++id;
+}
+function getCurrentId() {
+  return id;
+}
+
+function buildDocs() {
+  const template = fs.readFileSync("./docs/index.html.ejs", "utf-8");
+
+  fs.writeFileSync(
+    "./docs/index.html",
+    ejs.render(template, { getNewId, getCurrentId })
+  );
+}
+
+buildDocs();
diff --git a/docs/index.html b/docs/index.html.ejs
similarity index 94%
rename from docs/index.html
rename to docs/index.html.ejs
index f01b26c..0fc0bb3 100644
--- a/docs/index.html
+++ b/docs/index.html.ejs
@@ -166,8 +166,8 @@
         </p>
 
         <div class="example">
-          <input type="checkbox" id="example1">
-          <label for="example1">This is a checkbox</label>
+          <input type="checkbox" id="example<%= getNewId() %>">
+          <label for="example<%= getCurrentId() %>">This is a checkbox</label>
 
           <details>
             <summary>Show code</summary>
@@ -188,8 +188,8 @@
 
         <div class="example">
           <div class="field-row">
-            <input checked type="checkbox" id="example2">
-            <label for="example2">I am checked</label>
+            <input checked type="checkbox" id="example<%= getNewId() %>">
+            <label for="example<%= getCurrentId() %>">I am checked</label>
           </div>
           <div class="field-row">
             <input disabled type="checkbox" id="example3">
diff --git a/package-lock.json b/package-lock.json
new file mode 100644
index 0000000..f03891b
--- /dev/null
+++ b/package-lock.json
@@ -0,0 +1,14 @@
+{
+  "name": "98.css",
+  "version": "0.0.1",
+  "lockfileVersion": 1,
+  "requires": true,
+  "dependencies": {
+    "ejs": {
+      "version": "3.0.2",
+      "resolved": "https://registry.npmjs.org/ejs/-/ejs-3.0.2.tgz",
+      "integrity": "sha512-IncmUpn1yN84hy2shb0POJ80FWrfGNY0cxO9f4v+/sG7qcBvAtVWUA1IdzY/8EYUmOVhoKJVdJjNd3AZcnxOjA==",
+      "dev": true
+    }
+  }
+}
diff --git a/package.json b/package.json
index e0d7f77..cb580a6 100644
--- a/package.json
+++ b/package.json
@@ -7,7 +7,8 @@
     "doc": "docs"
   },
   "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "echo \"Error: no test specified\" && exit 1",
+    "build": "./build.js"
   },
   "repository": {
     "type": "git",
@@ -22,5 +23,8 @@
   "bugs": {
     "url": "https://github.com/jdan/windows98.css/issues"
   },
-  "homepage": "https://github.com/jdan/windows98.css#readme"
+  "homepage": "https://github.com/jdan/windows98.css#readme",
+  "devDependencies": {
+    "ejs": "^3.0.2"
+  }
 }