fix(sidebar): centrar labels (styles.css tenía mayor especificidad), preservar scroll al toggle

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

assets/css/styles.css

@@ -150,7 +150,7 @@ body {
 /* ── Etiquetas de categoría ───────────────────────────── */
 .sidebar-menu li.sidebar-section {
     border-bottom: none;
-    padding: 10px 16px 6px;
+    padding: 10px 30px 6px;
     font-size: 0.65rem;
     font-weight: 800;
     text-transform: uppercase;
@@ -158,18 +158,22 @@ body {
     color: rgba(255, 255, 255, 0.55);
     pointer-events: auto;
     cursor: pointer;
-    display: flex;
-    align-items: center;
-    justify-content: space-between;
-    gap: 5px;
+    display: block;
+    text-align: center;
     position: relative;
     z-index: 1;
     border-radius: 6px;
+    border-left: 3px solid transparent;
     margin: 4px 8px 0;
-    transition: background .15s, color .15s;
+    transition: background .15s, color .15s, border-color .15s;
 }
 .sidebar-menu li.sidebar-section:hover { color: rgba(255,255,255,.9); background: rgba(255,255,255,.07); }
-.sidebar-menu li.sidebar-section .sb-cat-label { display:flex; align-items:center; gap:4px; }
+.sidebar-menu li.sidebar-section.has-active {
+    border-left-color: rgba(255,255,255,.7);
+    background: rgba(255,255,255,.1);
+    color: #fff;
+}
+.sidebar-menu li.sidebar-section .sb-cat-label { display:inline-flex; align-items:center; gap:4px; }
 .sidebar-menu li.sidebar-section::after { display: none; }
 
 /* ── Badge dentro de un item ──────────────────────────── */