diff --git a/frontend/textbooks.html b/frontend/textbooks.html
index b219108..2f2923e 100644
--- a/frontend/textbooks.html
+++ b/frontend/textbooks.html
@@ -164,6 +164,13 @@
       width:auto; min-width:42px; padding:9px 12px;
       flex:0 0 auto;
     }
+    .tb-lab-btn {
+      width:auto; min-width:42px; padding:9px 12px;
+      flex:0 0 auto; white-space:nowrap;
+      font-variant-numeric: tabular-nums; font-weight:800;
+    }
+    .tb-lab-btn svg { stroke:var(--violet); flex-shrink:0; }
+    .tb-lab-btn:hover { border-color:var(--violet); background:rgba(155,93,229,.08); }
 
     .tb-empty {
       grid-column: 1 / -1;
@@ -521,9 +528,8 @@
               ${isTeacher ? `<button class="tb-btn tb-assign-btn" onclick="openAssignModal('${t.slug}', '${esc(t.title)}')" title="Назначить чтение как ДЗ">
                 <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.2" stroke-linecap="round" stroke-linejoin="round"><path d="M12 2v20M2 12h20"/></svg>
               </button>` : ''}
-              ${(labLinks[t.slug] && labLinks[t.slug].length) ? `<button class="tb-btn tb-lab-btn" onclick="openLabSim('${esc(labLinks[t.slug][0].id)}', event)" title="Открыть связанную симуляцию в лаборатории">
-                <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.2" stroke-linecap="round" stroke-linejoin="round"><path d="M9 3h6m-4.5 0v5.5l-4 7.5a1 1 0 0 0 .9 1.5h8.2a1 1 0 0 0 .9-1.5l-4-7.5V3"/></svg>
-                В лабораторию${labLinks[t.slug].length > 1 ? ' (' + labLinks[t.slug].length + ')' : ''}
+              ${(labLinks[t.slug] && labLinks[t.slug].length) ? `<button class="tb-btn tb-lab-btn" onclick="openLabSim('${esc(labLinks[t.slug][0].id)}', event)" title="В лабораторию${labLinks[t.slug].length > 1 ? ' — связанных симуляций: ' + labLinks[t.slug].length : ''}" aria-label="В лабораторию">
+                <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.2" stroke-linecap="round" stroke-linejoin="round"><path d="M9 3h6m-4.5 0v5.5l-4 7.5a1 1 0 0 0 .9 1.5h8.2a1 1 0 0 0 .9-1.5l-4-7.5V3"/></svg>${labLinks[t.slug].length > 1 ? labLinks[t.slug].length : ''}
               </button>` : ''}
             </div>
           </div>