/* ============================================================
   Sidebar — Dark Theme, Collapsible, Cascader Groups
   Pattern: MISA AMIS dark sidebar (aichat_misa.png reference)
   ============================================================ */

.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-width);
  height: 100vh;
  background: var(--sidebar-bg);
  color: var(--sidebar-text);
  display: flex;
  flex-direction: column;
  z-index: var(--z-sidebar);
  transition: width var(--sidebar-transition);
  overflow: hidden;
  user-select: none;
}

.sidebar.collapsed {
  width: var(--sidebar-collapsed);
}

/* === Logo Area === */
.sidebar-logo {
  display: flex;
  align-items: center;
  gap: var(--misa-space-10);
  padding: var(--misa-space-12) var(--misa-space-12);
  border-bottom: 1px solid var(--sidebar-border);
  min-height: 52px;
  flex-shrink: 0;
}

.sidebar-logo img {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
  border-radius: 6px;
}

.sidebar-logo-text {
  font-size: var(--misa-text-body);
  font-weight: var(--misa-fw-semibold);
  color: var(--sidebar-text-active);
  white-space: nowrap;
  overflow: hidden;
  opacity: 1;
  transition: opacity var(--transition-fast);
}

.sidebar.collapsed .sidebar-logo-text {
  opacity: 0;
  width: 0;
}

/* === Navigation === */
.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: var(--misa-space-8) 0;
}

/* === Menu Groups (Cascader) === */
.menu-group {
  margin-bottom: var(--misa-space-2);
}

.menu-group-header {
  display: flex;
  align-items: center;
  gap: var(--misa-space-8);
  padding: var(--misa-space-8) var(--misa-space-12);
  cursor: pointer;
  border-radius: 0;
  transition: background var(--transition-fast);
  width: 100%;
  text-align: left;
  font-size: var(--misa-text-body);
  font-weight: var(--misa-fw-medium);
  color: var(--sidebar-text);
}

.menu-group-header:hover {
  background: var(--sidebar-bg-hover);
  color: var(--sidebar-text-hover);
}

.menu-group-icon {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 16px;
}

.menu-group-label {
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  opacity: 1;
  transition: opacity var(--transition-fast);
}

.sidebar.collapsed .menu-group-label,
.sidebar.collapsed .menu-group-chevron {
  opacity: 0;
  width: 0;
  overflow: hidden;
}

.menu-group-chevron {
  width: 16px;
  height: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--transition-fast);
  font-size: 10px;
  color: var(--sidebar-text);
  flex-shrink: 0;
}

.menu-group.expanded .menu-group-chevron {
  transform: rotate(90deg);
}

/* === Menu Children (Cascader Items) === */
.menu-children {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-normal);
}

.menu-group.expanded .menu-children {
  max-height: 300px;
}

.sidebar.collapsed .menu-children {
  max-height: 0 !important;
}

.menu-item {
  display: flex;
  align-items: center;
  gap: var(--misa-space-8);
  padding: var(--misa-space-6) var(--misa-space-12) var(--misa-space-6) var(--misa-space-24);
  cursor: pointer;
  transition: background var(--transition-fast);
  width: 100%;
  text-align: left;
  font-size: var(--misa-text-sm);
  color: var(--sidebar-text);
  border-left: 2px solid transparent;
}

.menu-item:hover {
  background: var(--sidebar-bg-hover);
  color: var(--sidebar-text-hover);
}

.menu-item.active {
  background: var(--sidebar-bg-active);
  color: var(--sidebar-text-active);
  border-left-color: var(--misa-brand-accent);
}

.menu-item-icon {
  width: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 13px;
}

.menu-item-label {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  opacity: 1;
  transition: opacity var(--transition-fast);
}

.sidebar.collapsed .menu-item {
  padding-left: var(--misa-space-12);
}
.sidebar.collapsed .menu-item-label {
  opacity: 0;
  width: 0;
}

/* === Collapse Toggle === */
.sidebar-footer {
  border-top: 1px solid var(--sidebar-border);
  padding: var(--misa-space-8) var(--misa-space-12);
  flex-shrink: 0;
}

.sidebar-toggle {
  display: flex;
  align-items: center;
  gap: var(--misa-space-8);
  padding: var(--misa-space-6) var(--misa-space-4);
  border-radius: var(--misa-radius-sm);
  cursor: pointer;
  transition: background var(--transition-fast);
  width: 100%;
  text-align: left;
  font-size: var(--misa-text-sm);
  color: var(--sidebar-text);
}

.sidebar-toggle:hover {
  background: var(--sidebar-bg-hover);
  color: var(--sidebar-text-hover);
}

.sidebar-toggle-icon {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: transform var(--transition-normal);
}

.sidebar.collapsed .sidebar-toggle-icon {
  transform: rotate(180deg);
}

.sidebar-toggle-label {
  white-space: nowrap;
  opacity: 1;
  transition: opacity var(--transition-fast);
}

.sidebar.collapsed .sidebar-toggle-label {
  opacity: 0;
  width: 0;
}

/* === Tooltip (collapsed state) === */
.sidebar.collapsed .menu-group-header,
.sidebar.collapsed .menu-item {
  position: relative;
}

.sidebar.collapsed .menu-group-header:hover::after,
.sidebar.collapsed .menu-item:hover::after {
  content: attr(data-tooltip);
  position: absolute;
  left: calc(var(--sidebar-collapsed) + 8px);
  top: 50%;
  transform: translateY(-50%);
  background: #374151;
  color: #ffffff;
  padding: 4px 10px;
  border-radius: var(--misa-radius-sm);
  font-size: var(--misa-text-sm);
  white-space: nowrap;
  z-index: calc(var(--z-sidebar) + 10);
  pointer-events: none;
  box-shadow: var(--misa-shadow-md);
}

/* === Responsive === */
@media (max-width: 768px) {
  .sidebar {
    transform: translateX(-100%);
    box-shadow: var(--misa-shadow-lg);
  }
  .sidebar.mobile-open {
    transform: translateX(0);
  }
  .sidebar.collapsed {
    width: var(--sidebar-width);
  }
}