diff --git a/frontend/question-bank.html b/frontend/question-bank.html
index a333b50..fb1c7a7 100644
--- a/frontend/question-bank.html
+++ b/frontend/question-bank.html
@@ -262,7 +262,7 @@
 
         <div class="filter-section">
           <div class="filter-label">Тема</div>
-          <select class="filter-select" id="f-topic">
+          <select class="filter-select" id="f-topic" onchange="onFilterChange()">
             <option value="">Все темы</option>
           </select>
         </div>
@@ -476,14 +476,11 @@
     topicSel.innerHTML = '<option value="">Все темы</option>';
     if (!subject) return;
     try {
-      const data = await LS.api('/api/questions?subject=' + subject + '&limit=200');
-      const rows = data.rows || [];
-      const topicMap = new Map();
-      rows.forEach(q => { if (q.topic_id && q.topic) topicMap.set(q.topic_id, q.topic); });
-      topicMap.forEach((name, id) => {
+      const topics = await LS.api('/api/subjects/' + subject + '/topics');
+      (Array.isArray(topics) ? topics : []).forEach(t => {
         const opt = document.createElement('option');
-        opt.value = id;
-        opt.textContent = name;
+        opt.value = t.id;
+        opt.textContent = t.name + (t.question_count ? ' (' + t.question_count + ')' : '');
         topicSel.appendChild(opt);
       });
     } catch {}
@@ -498,9 +495,9 @@
     if (f.topic_id) params.set('topic_id', f.topic_id);
     if (f.difficulty) params.set('difficulty', f.difficulty);
     if (f.type) params.set('type', f.type);
-    if (f.sort === 'oldest') params.set('sort', 'oldest');
-    else if (f.sort === 'easy') params.set('sort', 'difficulty_asc');
-    else if (f.sort === 'hard') params.set('sort', 'difficulty_desc');
+    if (f.sort === 'oldest') params.set('sort', 'date_asc');
+    else if (f.sort === 'easy') params.set('sort', 'diff_asc');
+    else if (f.sort === 'hard') params.set('sort', 'diff_desc');
 
     document.getElementById('qb-grid').innerHTML = '<div style="grid-column:1/-1"><div class="spinner" style="margin:60px auto"></div></div>';
     document.getElementById('qb-pagination').style.display = 'none';