diff --git a/src/TaxBaik.Web/wwwroot/css/admin.css b/src/TaxBaik.Web/wwwroot/css/admin.css
index f4d7717..6e3caa0 100644
--- a/src/TaxBaik.Web/wwwroot/css/admin.css
+++ b/src/TaxBaik.Web/wwwroot/css/admin.css
@@ -1852,154 +1852,82 @@ textarea:focus-visible {
    Tabler Navbar Vertical (Admin Sidebar)
    ============================================================================ */
 
-.admin-sidebar-nav {
-  background: #1A2F4A;
-  border-right: 1px solid var(--border-color-light);
-  padding: 0;
-  min-height: 100%;
-  flex-direction: column;
-}
-
-.admin-sidebar-nav .navbar-brand {
-  padding: var(--space-3) var(--space-4);
-  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
-}
-
-.admin-sidebar-nav .navbar-brand a {
-  color: #FFFFFF;
-  font-weight: var(--font-weight-semibold);
-}
-
-.admin-sidebar-nav .navbar-nav {
-  flex-direction: column;
-  padding: var(--space-4) 0;
-}
-
-.admin-sidebar-nav .nav-item {
-  margin: 0;
-}
-
-.admin-sidebar-nav .nav-link {
-  display: flex;
-  align-items: center;
-  gap: var(--space-3);
-  padding: var(--space-3) var(--space-4);
-  color: rgba(255, 255, 255, 0.8);
-  text-decoration: none;
-  font-size: var(--font-size-sm);
-  font-weight: var(--font-weight-regular);
-  transition: all var(--transition-base);
-  position: relative;
-  border-left: 3px solid transparent;
-  margin: 0 var(--space-2);
-  border-radius: var(--radius-md);
-}
-
-.admin-sidebar-nav .nav-link:hover {
-  background-color: rgba(255, 255, 255, 0.1);
-  color: #FFFFFF;
-}
-
-.admin-sidebar-nav .nav-link.active {
-  background-color: rgba(255, 255, 255, 0.2);
-  color: #FFFFFF;
-  font-weight: var(--font-weight-semibold);
-  border-left-color: #FFFFFF;
-}
-
-.admin-sidebar-nav .nav-link-icon {
-  display: flex;
-  align-items: center;
-  justify-content: center;
-  width: 20px;
-  height: 20px;
-  flex-shrink: 0;
-  color: inherit;
-}
-
-.admin-sidebar-nav .nav-link-icon svg {
-  width: 20px;
-  height: 20px;
-  stroke: currentColor;
-  color: inherit;
-}
-
-.admin-sidebar-nav .nav-link-title {
-  flex: 1;
-  white-space: nowrap;
+.admin-sidebar-card {
+  border-radius: var(--radius-xl);
   overflow: hidden;
-  text-overflow: ellipsis;
+  box-shadow: var(--shadow-sm);
+  background: #1A2F4A;
 }
 
-.admin-sidebar-nav .dropdown-toggle::after {
-  content: '';
-  display: inline-block;
-  width: 0.3em;
-  height: 0.3em;
-  border: solid currentColor;
-  border-width: 0.15em 0.15em 0 0;
-  transform: rotate(45deg);
-  margin-left: auto;
-  transition: transform var(--transition-base);
-  color: inherit;
+.admin-sidebar-header {
+  background: #1A2F4A;
+  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
+  padding: var(--space-3) var(--space-4);
 }
 
-.admin-sidebar-nav .dropdown-toggle.show::after,
-.admin-sidebar-nav .dropdown-toggle:not(.collapsed)::after {
-  transform: rotate(-135deg);
+.admin-sidebar-body {
+  background: #1A2F4A;
+  padding: 0;
 }
 
-.admin-sidebar-nav .dropdown-menu {
+.admin-sidebar-card .accordion-button {
+  font-weight: var(--font-weight-semibold);
+  font-size: var(--font-size-sm);
+  color: rgba(255, 255, 255, 0.85);
+  background: transparent;
   border: none;
-  background: rgba(0, 0, 0, 0.2);
-  padding: var(--space-2) 0;
-  margin: 0;
-  border-radius: 0;
-  box-shadow: inset 2px 0 0 rgba(255, 255, 255, 0.1);
+  padding: var(--space-3) var(--space-4);
+  transition: all var(--transition-base);
 }
 
-.admin-sidebar-nav .dropdown-item {
-  padding: var(--space-3) var(--space-4) var(--space-3) calc(var(--space-4) + 20px + var(--space-3));
+.admin-sidebar-card .accordion-button:hover {
+  background: rgba(255, 255, 255, 0.08);
+  color: #FFFFFF;
+}
+
+.admin-sidebar-card .accordion-button:not(.collapsed) {
+  color: #FFFFFF;
+  background: rgba(255, 255, 255, 0.12);
+  box-shadow: inset 3px 0 0 #FFFFFF;
+}
+
+.admin-sidebar-card .accordion-button::after {
+  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none' stroke='rgba(255,255,255,0.6)' stroke-linecap='round' stroke-linejoin='round'%3e%3cpath d='M2 5l6 6 6-6'/%3e%3c/svg%3e");
+  width: 1.25rem;
+  height: 1.25rem;
+  margin-left: auto;
+}
+
+.admin-sidebar-card .accordion-button:not(.collapsed)::after {
+  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none' stroke='%23FFFFFF' stroke-linecap='round' stroke-linejoin='round'%3e%3cpath d='M2 5l6 6 6-6'/%3e%3c/svg%3e");
+}
+
+.admin-sidebar-card .list-group-item {
+  border: 0;
+  border-radius: 0;
+  padding: var(--space-3) var(--space-4);
   color: rgba(255, 255, 255, 0.75);
   font-size: var(--font-size-sm);
+  background: transparent;
   transition: all var(--transition-base);
   text-decoration: none;
+  margin: 0 var(--space-2);
+  margin-left: calc(var(--space-4) + 4px);
 }
 
-.admin-sidebar-nav .dropdown-item:hover {
-  background-color: rgba(255, 255, 255, 0.15);
+.admin-sidebar-card .list-group-item:hover {
+  background: rgba(255, 255, 255, 0.08);
   color: #FFFFFF;
 }
 
-.admin-sidebar-nav .dropdown-item.active {
-  background-color: rgba(255, 255, 255, 0.2);
+.admin-sidebar-card .list-group-item.active {
+  background: rgba(255, 255, 255, 0.15);
   color: #FFFFFF;
   font-weight: var(--font-weight-semibold);
+  border-left: 3px solid #FFFFFF;
+  padding-left: calc(var(--space-4) + 1px);
 }
 
-/* Responsive Navbar Toggler */
-.admin-sidebar-nav .navbar-toggler {
-  display: none;
-  border: none;
-  padding: var(--space-3) var(--space-4);
-  color: var(--text-primary);
-}
-
-@media (max-width: 991px) {
-  .admin-sidebar-nav .navbar-toggler {
-    display: block;
-  }
-
-  .admin-sidebar-nav {
-    position: sticky;
-    top: 0;
-  }
-
-  .admin-sidebar-nav .navbar-collapse {
-    max-height: calc(100vh - 150px);
-    overflow-y: auto;
-  }
-
   .admin-drawer-footer {
     display: none;
   }