/**
 * LifeOS Design System — Application Layout
 * Structure: Left Sidebar, Sticky Header, Main Scrollable Content Area
 */

/* Main Application Shell */
.app-shell {
  display: flex;
  min-height: 100vh;
  background-color: var(--bg-primary);
  position: relative;
}

/* ==========================================================================
   LEFT SIDEBAR
   ========================================================================== */
.sidebar {
  width: var(--sidebar-width);
  background-color: var(--bg-sidebar);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: var(--z-sidebar);
  transition: transform var(--transition-normal), width var(--transition-normal);
  user-select: none;
}

/* Sidebar Brand Header */
.sidebar-brand {
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-5);
  border-bottom: 1px solid var(--border);
}

.brand-link {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
}

.brand-logo {
  width: 34px;
  height: 34px;
  flex-shrink: 0;
}

.brand-info {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-size: var(--font-size-md);
  font-weight: var(--font-weight-bold);
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

.brand-tag {
  font-size: 0.6875rem;
  color: var(--accent-primary);
  font-weight: var(--font-weight-medium);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* Sidebar Navigation Scrollable Area */
.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: var(--space-4) var(--space-3);
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

/* Navigation Groups */
.nav-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.nav-group-title {
  font-size: 0.6875rem;
  font-weight: var(--font-weight-bold);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  padding: var(--space-2) var(--space-3) var(--space-1);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* Navigation Items */
.nav-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: 0.55rem var(--space-3);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  text-decoration: none;
  transition: background-color var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast);
  position: relative;
  border-left: 2px solid transparent;
}

.nav-item:hover {
  background-color: var(--accent-primary-subtle);
  color: var(--text-primary);
}

.nav-item.active {
  background-color: var(--accent-primary-subtle);
  color: var(--accent-primary);
  border-left-color: var(--accent-primary);
  font-weight: var(--font-weight-semibold);
}

.nav-icon {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  stroke-width: 2;
  color: inherit;
}

.nav-label {
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.nav-badge {
  font-size: 0.6875rem;
  padding: 0.1rem 0.4rem;
  border-radius: var(--radius-full);
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-secondary);
}

/* Sidebar Footer */
.sidebar-footer {
  padding: var(--space-3) var(--space-4);
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background-color: var(--bg-sidebar);
}

.sidebar-toggle-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: var(--space-1);
  border-radius: var(--radius-xs);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color var(--transition-fast);
}

.sidebar-toggle-btn:hover {
  color: var(--text-primary);
}

/* Mobile Sidebar Backdrop */
.sidebar-backdrop {
  position: fixed;
  inset: 0;
  background-color: var(--bg-modal-backdrop);
  z-index: calc(var(--z-sidebar) - 1);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-normal);
  backdrop-filter: blur(3px);
}

.sidebar-backdrop.active {
  opacity: 1;
  pointer-events: auto;
}

/* ==========================================================================
   TOP HEADER
   ========================================================================== */
.header {
  height: var(--header-height);
  background-color: rgba(15, 17, 23, 0.85);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  right: 0;
  left: var(--sidebar-width);
  z-index: var(--z-header);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-8);
  transition: left var(--transition-normal);
}

.header-left {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.header-menu-btn {
  display: none; /* Shown on tablet / mobile via responsive.css */
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  padding: var(--space-2);
  cursor: pointer;
  align-items: center;
  justify-content: center;
}

.header-menu-btn:hover {
  background-color: var(--bg-card);
  color: var(--text-primary);
}

.header-breadcrumbs {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--font-size-sm);
}

.breadcrumb-item {
  color: var(--text-muted);
}

.breadcrumb-separator {
  color: var(--border);
}

.breadcrumb-current {
  color: var(--text-primary);
  font-weight: var(--font-weight-semibold);
}

.header-right {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

/* Status Pill */
.status-pill {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: 0.3rem 0.65rem;
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  font-size: var(--font-size-xs);
  color: var(--text-secondary);
}

.status-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--success);
  box-shadow: 0 0 6px var(--success);
}

/* Header Action Buttons */
.header-action-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  position: relative;
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.header-action-btn:hover {
  background-color: var(--bg-card);
  color: var(--text-primary);
}

.notification-badge {
  position: absolute;
  top: 6px;
  right: 6px;
  width: 7px;
  height: 7px;
  background-color: var(--accent-primary);
  border-radius: 50%;
  box-shadow: 0 0 4px var(--accent-primary);
}

/* User Profile Trigger & Dropdown */
.user-profile-menu {
  position: relative;
}

.user-profile-btn {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  background: transparent;
  border: 1px solid var(--border);
  padding: 0.3rem var(--space-3);
  border-radius: var(--radius-full);
  cursor: pointer;
  color: var(--text-primary);
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
}

.user-profile-btn:hover {
  background-color: var(--bg-card);
  border-color: var(--accent-primary);
}

.user-avatar-img {
  width: 28px;
  height: 28px;
  border-radius: 50%;
}

.user-info {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  text-align: left;
}

.user-name {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--text-primary);
  line-height: 1.1;
}

.user-role {
  font-size: 0.6875rem;
  color: var(--text-muted);
}

/* Dropdown Menu Container */
.dropdown-menu {
  position: absolute;
  top: calc(100% + var(--space-2));
  right: 0;
  width: 220px;
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  padding: var(--space-2);
  display: none;
  flex-direction: column;
  gap: 2px;
  z-index: var(--z-dropdown);
  animation: dropdownFadeIn var(--transition-fast);
}

.dropdown-menu.show {
  display: flex;
}

@keyframes dropdownFadeIn {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: translateY(0); }
}

.dropdown-header {
  padding: var(--space-2) var(--space-3);
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: var(--space-1);
}

.dropdown-header-name {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--text-primary);
}

.dropdown-header-email {
  font-size: var(--font-size-xs);
  color: var(--text-muted);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.dropdown-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-3);
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
  border-radius: var(--radius-xs);
  text-decoration: none;
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.dropdown-item:hover {
  background-color: var(--accent-primary-subtle);
  color: var(--text-primary);
}

.dropdown-divider {
  height: 1px;
  background-color: var(--border-subtle);
  margin: var(--space-1) 0;
}

/* ==========================================================================
   MAIN CONTENT WRAPPER
   ========================================================================== */
.main-wrapper {
  flex: 1;
  margin-left: var(--sidebar-width);
  display: flex;
  flex-direction: column;
  min-width: 0;
  transition: margin-left var(--transition-normal);
}

.main-content {
  flex: 1;
  padding: var(--space-8);
  max-width: 1440px;
  width: 100%;
  margin: 0 auto;
}

/* Page Header Block */
.page-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: var(--space-8);
  gap: var(--space-4);
  flex-wrap: wrap;
}

.page-header-info {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.page-title {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  color: var(--text-primary);
}

.page-subtitle {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
}

.page-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-wrap: wrap;
}