diff --git a/build.js b/build.js
index c45db23..cd85d79 100644
--- a/build.js
+++ b/build.js
@@ -1,68 +1,92 @@
-import{readFileSync,writeFileSync,mkdirSync,cpSync,readdirSync,existsSync,statSync}from'fs'
-import{join,extname}from'path'
-import matter from'gray-matter'
-import{marked}from'marked'
+import { readFileSync, writeFileSync, mkdirSync, cpSync, readdirSync, existsSync, statSync } from 'fs'
+import { join } from 'path'
+import matter from 'gray-matter'
+import { marked } from 'marked'
 
-const ARTICLES='articles',DIST='dist',TEMPLATES='templates',STATIC='static'
+const ARTICLES = 'articles'
+const DIST = 'dist'
+const TEMPLATES = 'templates'
+const STATIC = 'static'
 
-const template=n=>readFileSync(join(TEMPLATES,n),'utf-8')
-const articleTmpl=template('article.html')
-const homeTmpl=template('home.html')
+const template = n => readFileSync(join(TEMPLATES, n), 'utf-8')
+const articleTmpl = template('article.html')
+const homeTmpl = template('home.html')
 
-mkdirSync(DIST,{recursive:true})
+const render = (tpl, data) =>
+  tpl.replace(/{{\s*([a-zA-Z0-9_]+)\s*}}/g, (_, key) => `${data[key] ?? ''}`)
 
-if(existsSync(STATIC))
-  cpSync(STATIC,DIST,{recursive:true})
+const fmtDateLong = d =>
+  d ? new Date(d).toLocaleDateString('en-US', { month: 'long', day: 'numeric', year: 'numeric' }) : ''
 
-const articles=[]
+const fmtDateIso = d => (d ? new Date(d).toISOString().split('T')[0] : '')
 
-for(const slug of readdirSync(ARTICLES)){
-  const dir=join(ARTICLES,slug)
-  if(!statSync(dir).isDirectory()) continue
+mkdirSync(DIST, { recursive: true })
 
-  const mdPath=join(dir,'index.md')
-  if(!existsSync(mdPath)) continue
+if (existsSync(STATIC)) cpSync(STATIC, DIST, { recursive: true })
 
-  const{data,content}=matter(readFileSync(mdPath,'utf-8'))
-  const html=marked(content)
+const articles = []
 
-  const outDir=join(DIST,slug)
-  mkdirSync(outDir,{recursive:true})
+for (const slug of readdirSync(ARTICLES)) {
+  const dir = join(ARTICLES, slug)
+  if (!statSync(dir).isDirectory()) continue
 
-  // copy co-located assets
-  for(const f of readdirSync(dir)){
-    if(f==='index.md') continue
-    cpSync(join(dir,f),join(outDir,f))
+  const mdPath = join(dir, 'index.md')
+  if (!existsSync(mdPath)) continue
+
+  const { data, content } = matter(readFileSync(mdPath, 'utf-8'))
+  const html = marked(content)
+
+  const outDir = join(DIST, slug)
+  mkdirSync(outDir, { recursive: true })
+
+  for (const f of readdirSync(dir)) {
+    if (f === 'index.md') continue
+    cpSync(join(dir, f), join(outDir, f), { recursive: true })
   }
 
-  const page=articleTmpl
-    .replace('{{title}}',data.title||slug)
-    .replace('{{date}}',data.date?new Date(data.date).toLocaleDateString('en-US',{month:'long',day:'numeric',year:'numeric'}):'')
-    .replace('{{date_iso}}',data.date?new Date(data.date).toISOString().split('T')[0]:'')
-    .replace('{{tags}}', (data.tags||[]).map(t=>`<span class="inline-flex items-center rounded-full border border-gray-200 bg-gray-50 px-2 py-0.5 text-xs font-medium text-gray-600 mono">${t}</span>`).join(' '))
-    .replace('{{excerpt}}',data.excerpt||'')
-    .replace('{{slug}}',slug)
-    .replace('{{body}}',html)
+  const page = render(articleTmpl, {
+    title: data.title || slug,
+    date: fmtDateLong(data.date),
+    date_iso: fmtDateIso(data.date),
+    tags: (data.tags || [])
+      .map(
+        t =>
+          `<span class="inline-flex items-center rounded-full border border-gray-200 bg-gray-50 px-2 py-0.5 text-xs font-medium text-gray-600 mono">${t}</span>`
+      )
+      .join(' '),
+    excerpt: data.excerpt || '',
+    slug,
+    body: html
+  })
 
-  writeFileSync(join(outDir,'index.html'),page)
-  articles.push({slug,...data})
+  writeFileSync(join(outDir, 'index.html'), page)
+  articles.push({ slug, ...data })
   console.log(`✅ ${slug}`)
 }
 
-articles.sort((a,b)=>new Date(b.date)-new Date(a.date))
+articles.sort((a, b) => new Date(b.date) - new Date(a.date))
 
-const articleListHtml=articles.map(a=>`
+const articleListHtml = articles
+  .map(
+    a => `
   <a href="/${a.slug}/" class="block rounded-2xl border border-gray-200 bg-white shadow-sm hover:shadow-md transition-shadow overflow-hidden">
     <div class="px-5 py-4">
       <div class="flex items-start justify-between gap-4">
         <h2 class="text-base font-semibold text-gray-900">${a.title}</h2>
-        <time datetime="${new Date(a.date).toISOString().split('T')[0]}" class="mono text-xs text-gray-400 whitespace-nowrap mt-0.5">${new Date(a.date).toLocaleDateString('en-US',{month:'short',day:'numeric'})}</time>
+        <time datetime="${new Date(a.date).toISOString().split('T')[0]}" class="mono text-xs text-gray-400 whitespace-nowrap mt-0.5">${new Date(a.date).toLocaleDateString('en-US', { month: 'short', day: 'numeric' })}</time>
       </div>
-      ${a.excerpt?`<p class="text-sm text-gray-500 mt-1.5">${a.excerpt}</p>`:''}
-      <div class="flex gap-1.5 mt-3">${(a.tags||[]).map(t=>`<span class="inline-flex items-center rounded-full border border-gray-200 bg-gray-50 px-2 py-0.5 text-xs font-medium text-gray-600 mono">${t}</span>`).join('')}</div>
+      ${a.excerpt ? `<p class="text-sm text-gray-500 mt-1.5">${a.excerpt}</p>` : ''}
+      <div class="flex gap-1.5 mt-3">${(a.tags || [])
+        .map(
+          t =>
+            `<span class="inline-flex items-center rounded-full border border-gray-200 bg-gray-50 px-2 py-0.5 text-xs font-medium text-gray-600 mono">${t}</span>`
+        )
+        .join('')}</div>
     </div>
-  </a>`).join('\n')
+  </a>`
+  )
+  .join('\n')
 
-const home=homeTmpl.replace('{{articles}}',articleListHtml)
-writeFileSync(join(DIST,'index.html'),home)
+const home = render(homeTmpl, { articles: articleListHtml })
+writeFileSync(join(DIST, 'index.html'), home)
 console.log(`\n🏠 index.html → ${articles.length} article(s)`)