Add existing modifications

tony/dynamic_native_tabs.css

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+/* Transição suave para o TabsToolbar */
+#main-window #TabsToolbar {
+    overflow: hidden;
+    max-height: 3em; /* Estado expandido */
+    transition: max-height 0.3s ease-in-out !important;
+}
+
+/* Toolbar items */
+#main-window #TabsToolbar .toolbar-items {
+    overflow: hidden;
+    max-height: 40px; /* Estado expandido */
+    transition: max-height 0.3s ease-in-out !important;
+}
+
+/* Estado oculto: TabsToolbar colapsado */
+#main-window[titlepreface*="​"] #TabsToolbar {
+    max-height: 0; /* Estado colapsado */
+    visibility: hidden; /* Evita conteúdo interativo enquanto colapsado */
+    transition: max-height 0.3s ease-in-out, visibility 0s 0.3s !important; /* atraso para ocultar */
+}
+
+/* Estado oculto para os itens da toolbar */
+#main-window[titlepreface*="​"] #TabsToolbar .toolbar-items {
+    max-height: 0;
+}
+
+/* Corrige o z-index de abas fixadas */
+#main-window[titlepreface*="​"] #tabbrowser-tabs {
+    z-index: 0 !important;
+}