Add shareable URLs for posts with copy link button

Hash-based URLs (#resepti/slug) allow sharing individual posts on social media.
Modal shows "Kopioi linkki" button, hash auto-opens post on page load.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

script.js

@@ -84,6 +84,16 @@ function applyTranslations() {
 // ===========================
 // HELPERS
 // ===========================
+function postSlug(title) {
+  return title.toLowerCase()
+    .replace(/[äå]/g, 'a').replace(/ö/g, 'o').replace(/ü/g, 'u')
+    .replace(/[^a-z0-9]+/g, '-').replace(/^-|-$/g, '');
+}
+
+function findPostBySlug(slug) {
+  return APP.posts.find(p => postSlug(p.title) === slug);
+}
+
 function sortSubcategories(subs) {
   return [...subs].sort((a, b) => {
     const aM = a.fi.toLowerCase() === 'muut' ? 1 : 0;
@@ -343,6 +353,7 @@ async function openPost(id) {
     <div class="modal-like-row">
       <button class="like-btn ${liked ? 'liked' : ''}" data-like-id="${p.id}" onclick="toggleLike('${p.id}')">${liked ? t('liked_btn') : t('like_btn')}</button>
       <span class="like-count" data-like-count="${p.id}">${likeCount}</span>
+      <button class="copy-link-btn" onclick="copyPostLink('${postSlug(p.title)}')" style="margin-left:auto;padding:4px 14px;font-size:0.82rem;border:1px solid #ccc;background:#fff;border-radius:20px;cursor:pointer;">🔗 Kopioi linkki</button>
     </div>
     ${bodyHTML}
     <div class="comments-section">
@@ -365,6 +376,9 @@ async function openPost(id) {
   document.getElementById('modalOverlay').classList.add('open');
   document.body.style.overflow = 'hidden';
 
+  // Update URL hash for shareable link
+  history.replaceState(null, '', '#resepti/' + postSlug(p.title));
+
   const qEl = document.getElementById('captcha-question');
   if (qEl) qEl.textContent = generateCaptcha();
 }
@@ -420,9 +434,19 @@ async function submitComment(e, postId) {
   if (headEl) headEl.textContent = `${t('modal_comments')} (${comments.length})`;
 }
 
+function copyPostLink(slug) {
+  const url = window.location.origin + window.location.pathname + '#resepti/' + slug;
+  navigator.clipboard.writeText(url).then(() => {
+    const btn = document.querySelector('.copy-link-btn');
+    if (btn) { btn.textContent = '✓ Kopioitu!'; setTimeout(() => { btn.textContent = '🔗 Kopioi linkki'; }, 2000); }
+  });
+}
+
 function closeModal() {
   document.getElementById('modalOverlay').classList.remove('open');
   document.body.style.overflow = '';
+  // Clear URL hash
+  history.replaceState(null, '', window.location.pathname + window.location.search);
 }
 
 // ===========================
@@ -896,6 +920,26 @@ async function init() {
   renderCategoryFilters();
   renderSubFilters();
   renderCards();
+
+  // Open post from URL hash (e.g. #resepti/pinaattiletut)
+  const hash = window.location.hash;
+  if (hash.startsWith('#resepti/')) {
+    const slug = hash.slice('#resepti/'.length);
+    const post = findPostBySlug(slug);
+    if (post) openPost(post.id);
+  }
 }
 
+// Handle browser back/forward with hash
+window.addEventListener('hashchange', () => {
+  const hash = window.location.hash;
+  if (hash.startsWith('#resepti/')) {
+    const slug = hash.slice('#resepti/'.length);
+    const post = findPostBySlug(slug);
+    if (post) openPost(post.id);
+  } else {
+    closeModal();
+  }
+});
+
 init();