a11y: WCAG AA contrast + ARIA roles + focus management across all pages

- css/ls.css: --text-3 #8898AA → #56687A (5.1:1 contrast), min-height 44px on .btn-primary/.btn-ghost/.sb-link, new .icon-btn utility (44×44px)
- js/api.js: lsConfirm — role=dialog, aria-modal, aria-labelledby, Tab focus trap, restore focus on close; lsToast — aria-live=polite on container, role=alert on errors; live quiz — role=dialog, role=radiogroup, role=radio, aria-checked, keyboard support
- test-run.html: q-opt divs — role=radio/checkbox, aria-checked, tabindex, keyboard enter/space; confirm modal — role=dialog, aria-modal; btn-flag — aria-pressed; dots — aria-label, aria-current; touch targets 44px
- board.html: btn-del-ann — aria-label; reaction buttons — aria-label, aria-pressed
- All 18 HTML files: replace hardcoded color:#8898AA with color:var(--text-3)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/admin.html

@@ -60,7 +60,7 @@
       background: rgba(15,23,42,0.05); color: #64748B;
     }
     .sc-tag-mode { background: rgba(155,93,229,0.08); color: var(--violet); }
-    .sc-qcount { font-size: 0.72rem; color: #8898AA; font-weight: 600; }
+    .sc-qcount { font-size: 0.72rem; color: var(--text-3); font-weight: 600; }
     .sc-chevron {
       width: 20px; height: 20px; color: #cbd5e1; transition: transform 0.2s; flex-shrink: 0;
     }
@@ -89,7 +89,7 @@
     .sc-fields { display: flex; flex-direction: column; gap: 12px; }
     .sc-field { display: flex; align-items: center; gap: 10px; }
     .sc-label {
-      font-size: 0.72rem; color: #8898AA; font-weight: 700; white-space: nowrap;
+      font-size: 0.72rem; color: var(--text-3); font-weight: 700; white-space: nowrap;
       text-transform: uppercase; letter-spacing: 0.04em; min-width: 68px;
     }
     .sc-select {
@@ -110,7 +110,7 @@
     .sc-src-btn {
       flex: 1; padding: 6px 12px; border: none; border-radius: 8px; background: transparent;
       font-family: 'Manrope', sans-serif; font-size: 0.76rem; font-weight: 600;
-      color: #8898AA; cursor: pointer; transition: all 0.15s; text-align: center;
+      color: var(--text-3); cursor: pointer; transition: all 0.15s; text-align: center;
     }
     .sc-src-btn.active { background: #fff; color: var(--violet); box-shadow: 0 1px 4px rgba(15,23,42,0.08); }
     .sc-test-pick { display: none; flex-direction: column; gap: 10px; }
@@ -661,7 +661,7 @@
       font-size: 0.78rem; color: #64748B; font-family: monospace;
     }
     .sl-assignment { font-weight: 600; color: #3D4F6B; }
-    .sl-class { font-size: 0.78rem; color: #8898AA; }
+    .sl-class { font-size: 0.78rem; color: var(--text-3); }
 
     .sl-status {
       display: inline-flex; align-items: center; gap: 4px;
@@ -696,7 +696,7 @@
     .sl-role-student { background: rgba(6,214,224,0.1); color: #06aab3; }
 
     .sl-empty {
-      padding: 48px 24px; text-align: center; color: #8898AA; font-size: 0.88rem;
+      padding: 48px 24px; text-align: center; color: var(--text-3); font-size: 0.88rem;
     }
     .sl-empty-icon { margin-bottom: 12px; opacity: 0.3; }
 
@@ -708,7 +708,7 @@
       transition: border-color 0.15s;
     }
     .sl-filter-select:focus { border-color: var(--violet); outline: none; }
-    .sl-count { font-size: 0.78rem; color: #8898AA; font-weight: 600; }
+    .sl-count { font-size: 0.78rem; color: var(--text-3); font-weight: 600; }
 
     /* ══════════ CLASSROOM ADMIN TAB ══════════ */
     .cr-admin-section { margin-bottom: 40px; }
@@ -3454,17 +3454,17 @@
 
     function renderAcFiles(q) {
       const el = document.getElementById('acf-file-list');
-      if (!_acAllFiles) { el.innerHTML = '<div style="padding:10px;color:#8898AA;font-size:.82rem;text-align:center">Загрузка…</div>'; return; }
+      if (!_acAllFiles) { el.innerHTML = '<div style="padding:10px;color:var(--text-3);font-size:.82rem;text-align:center">Загрузка…</div>'; return; }
       const lq = q.toLowerCase();
       const items = q ? _acAllFiles.filter(f => (f.title||'').toLowerCase().includes(lq)) : _acAllFiles;
       const SUBJ = { bio:'Биология', chem:'Химия', math:'Математика', phys:'Физика' };
-      if (!items.length) { el.innerHTML = '<div style="padding:10px;color:#8898AA;font-size:.82rem;text-align:center">Нет файлов</div>'; return; }
+      if (!items.length) { el.innerHTML = '<div style="padding:10px;color:var(--text-3);font-size:.82rem;text-align:center">Нет файлов</div>'; return; }
       el.innerHTML = items.map(f => `
         <div onclick="selectAcFile(${f.id},'${esc(f.title||'Файл')}','${f.subject_slug||''}')"
              style="padding:9px 12px;cursor:pointer;border-bottom:1px solid rgba(15,23,42,0.07);display:flex;align-items:center;gap:8px;${_acFileId===f.id?'background:rgba(155,93,229,0.08);':''} transition:background .15s">
           <div style="flex:1">
             <div style="font-size:.84rem;font-weight:600">${esc(f.title||'Файл')}</div>
-            <div style="font-size:.74rem;color:#8898AA">${SUBJ[f.subject_slug]||f.subject_slug||''}</div>
+            <div style="font-size:.74rem;color:var(--text-3)">${SUBJ[f.subject_slug]||f.subject_slug||''}</div>
           </div>
           ${_acFileId===f.id ? '<span style="color:var(--violet)"><i data-lucide="check" style="width:15px;height:15px"></i></span>' : ''}
         </div>`).join('');
@@ -4819,7 +4819,7 @@
       try {
         const rows = await LS.api(`/api/admin/topics?subject_id=${subjId}`);
         document.getElementById('topics-count').textContent = rows.length + ' тем';
-        if (!rows.length) { el.innerHTML = '<div style="padding:32px;text-align:center;color:#8898AA">Тем нет</div>'; return; }
+        if (!rows.length) { el.innerHTML = '<div style="padding:32px;text-align:center;color:var(--text-3)">Тем нет</div>'; return; }
         el.innerHTML = '<div style="display:flex;flex-direction:column;gap:6px">' + rows.map(t => `
           <div class="adm-panel" style="padding:12px 18px;margin:0;display:flex;align-items:center;gap:14px">
             <span style="font-size:0.75rem;color:var(--text-3);font-weight:700;min-width:28px">#${t.order_index}</span>
@@ -4887,7 +4887,7 @@
       el.innerHTML = LS.skeleton(5, 'row');
       try {
         const rows = await LS.api('/api/admin/audit-log?limit=200');
-        if (!rows.length) { el.innerHTML = '<div style="padding:32px;text-align:center;color:#8898AA">Журнал пуст</div>'; return; }
+        if (!rows.length) { el.innerHTML = '<div style="padding:32px;text-align:center;color:var(--text-3)">Журнал пуст</div>'; return; }
         const ACTION_LABELS = {
           'user.role_change': 'Смена роли', 'user.edit': 'Редактирование', 'user.ban': 'Блокировка',
           'user.unban': 'Разблокировка', 'user.delete': 'Удаление', 'user.clear_sessions': 'Очистка истории',
@@ -4918,7 +4918,7 @@
       if (!await LS.confirm('Очистить весь аудит-лог?', { danger: true })) return;
       try {
         await LS.api('/api/admin/audit-log', { method:'DELETE' });
-        document.getElementById('audit-list').innerHTML = '<div style="padding:32px;text-align:center;color:#8898AA">Журнал очищен</div>';
+        document.getElementById('audit-list').innerHTML = '<div style="padding:32px;text-align:center;color:var(--text-3)">Журнал очищен</div>';
         LS.toast('Журнал очищен', 'success');
       } catch (e) { LS.toast(e.message, 'error'); }
     }
@@ -4929,7 +4929,7 @@
       el.innerHTML = LS.skeleton(3, 'row');
       try {
         const rows = await LS.api('/api/admin/error-log?limit=200');
-        if (!rows.length) { el.innerHTML = '<div style="padding:32px;text-align:center;color:#8898AA;font-size:0.88rem">Ошибок нет</div>'; return; }
+        if (!rows.length) { el.innerHTML = '<div style="padding:32px;text-align:center;color:var(--text-3);font-size:0.88rem">Ошибок нет</div>'; return; }
         el.innerHTML = rows.map(r => {
           const dt = new Date(r.created_at);
           const ds = dt.toLocaleDateString('ru',{day:'numeric',month:'short'}) + ' ' + dt.toLocaleTimeString('ru',{hour:'2-digit',minute:'2-digit'});
@@ -4949,7 +4949,7 @@
       if (!await LS.confirm('Очистить журнал ошибок?', { danger: true })) return;
       try {
         await LS.api('/api/admin/error-log', { method:'DELETE' });
-        document.getElementById('errors-list').innerHTML = '<div style="padding:32px;text-align:center;color:#8898AA">Журнал очищен</div>';
+        document.getElementById('errors-list').innerHTML = '<div style="padding:32px;text-align:center;color:var(--text-3)">Журнал очищен</div>';
         LS.toast('Журнал очищен', 'success');
       } catch (e) { LS.toast(e.message, 'error'); }
     }