/**
 * Luna Design System - Layout Components
 * Structural components for building application layouts
 */

/* ============================================
   PAGE LAYOUT
   ============================================ */

.luna-app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--luna-bg-gradient);
}

.luna-app::before {
  content: '';
  position: fixed;
  inset: 0;
  background: var(--luna-bg-overlay);
  pointer-events: none;
  z-index: 0;
}

.luna-main {
  flex: 1;
  position: relative;
  z-index: 1;
}

/* ============================================
   HEADER
   ============================================ */

.luna-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--luna-glass);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--luna-glass-border);
  padding: var(--luna-space-4) var(--luna-space-6);
}

.luna-header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1400px;
  margin: 0 auto;
}

.luna-header-brand {
  display: flex;
  align-items: center;
  gap: var(--luna-space-3);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--luna-text);
  text-decoration: none;
}

.luna-header-nav {
  display: flex;
  align-items: center;
  gap: var(--luna-space-2);
}

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

/* ============================================
   SIDEBAR
   ============================================ */

.luna-sidebar {
  width: 280px;
  background: var(--luna-glass);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-right: 1px solid var(--luna-glass-border);
  padding: var(--luna-space-6);
  height: 100vh;
  position: sticky;
  top: 0;
  overflow-y: auto;
}

.luna-sidebar-header {
  display: flex;
  align-items: center;
  gap: var(--luna-space-3);
  margin-bottom: var(--luna-space-6);
  padding-bottom: var(--luna-space-4);
  border-bottom: 1px solid var(--luna-glass-border);
}

.luna-sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: var(--luna-space-1);
}

.luna-sidebar-link {
  display: flex;
  align-items: center;
  gap: var(--luna-space-3);
  padding: var(--luna-space-3) var(--luna-space-4);
  color: var(--luna-text-secondary);
  text-decoration: none;
  border-radius: var(--luna-radius-md);
  font-weight: 500;
  transition: var(--luna-transition-fast);
}

.luna-sidebar-link:hover {
  background: rgba(var(--luna-primary-rgb), 0.1);
  color: var(--luna-text);
}

.luna-sidebar-link.active {
  background: var(--luna-primary);
  color: white;
}

.luna-sidebar-section {
  margin-top: var(--luna-space-6);
}

.luna-sidebar-section-title {
  font-size: 0.6875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--luna-text-tertiary);
  padding: 0 var(--luna-space-4);
  margin-bottom: var(--luna-space-2);
}

/* Collapsed sidebar */
.luna-sidebar-collapsed {
  width: 72px;
  padding: var(--luna-space-4);
}

.luna-sidebar-collapsed .luna-sidebar-link span,
.luna-sidebar-collapsed .luna-sidebar-section-title {
  display: none;
}

.luna-sidebar-collapsed .luna-sidebar-link {
  justify-content: center;
  padding: var(--luna-space-3);
}

/* ============================================
   FOOTER
   ============================================ */

.luna-footer {
  background: var(--luna-glass);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-top: 1px solid var(--luna-glass-border);
  padding: var(--luna-space-6);
  position: relative;
  z-index: 1;
}

.luna-footer-content {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.luna-footer-text {
  color: var(--luna-text-secondary);
  font-size: 0.875rem;
}

.luna-footer-links {
  display: flex;
  gap: var(--luna-space-4);
}

.luna-footer-link {
  color: var(--luna-text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  transition: var(--luna-transition-fast);
}

.luna-footer-link:hover {
  color: var(--luna-primary);
}

/* ============================================
   PAGE SECTIONS
   ============================================ */

.luna-section {
  padding: var(--luna-space-8) 0;
}

.luna-section-header {
  margin-bottom: var(--luna-space-6);
}

.luna-section-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--luna-text);
  margin: 0 0 var(--luna-space-2) 0;
}

.luna-section-description {
  color: var(--luna-text-secondary);
  font-size: 0.9375rem;
  margin: 0;
}

/* ============================================
   DIVIDERS
   ============================================ */

.luna-divider {
  height: 1px;
  background: var(--luna-glass-border);
  margin: var(--luna-space-6) 0;
}

.luna-divider-vertical {
  width: 1px;
  height: auto;
  align-self: stretch;
  margin: 0 var(--luna-space-4);
}

.luna-divider-text {
  display: flex;
  align-items: center;
  gap: var(--luna-space-4);
  color: var(--luna-text-tertiary);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.luna-divider-text::before,
.luna-divider-text::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--luna-glass-border);
}

/* ============================================
   STACK (Vertical Spacing)
   ============================================ */

.luna-stack {
  display: flex;
  flex-direction: column;
}

.luna-stack-1 { gap: var(--luna-space-1); }
.luna-stack-2 { gap: var(--luna-space-2); }
.luna-stack-3 { gap: var(--luna-space-3); }
.luna-stack-4 { gap: var(--luna-space-4); }
.luna-stack-6 { gap: var(--luna-space-6); }
.luna-stack-8 { gap: var(--luna-space-8); }

/* ============================================
   SKELETON LOADING
   ============================================ */

.luna-skeleton {
  background: linear-gradient(
    90deg,
    var(--luna-glass-light) 25%,
    rgba(255, 255, 255, 0.9) 50%,
    var(--luna-glass-light) 75%
  );
  background-size: 200% 100%;
  animation: luna-skeleton-shimmer 1.5s infinite;
  border-radius: var(--luna-radius-sm);
}

.luna-skeleton-text {
  height: 1em;
  margin-bottom: 0.5em;
}

.luna-skeleton-text:last-child {
  width: 80%;
}

.luna-skeleton-circle {
  border-radius: 50%;
}

.luna-skeleton-card {
  height: 200px;
  border-radius: var(--luna-radius-xl);
}

@keyframes luna-skeleton-shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

[data-theme="dark"] .luna-skeleton {
  background: linear-gradient(
    90deg,
    rgba(40, 40, 40, 0.5) 25%,
    rgba(60, 60, 60, 0.5) 50%,
    rgba(40, 40, 40, 0.5) 75%
  );
  background-size: 200% 100%;
}

/* ============================================
   EMPTY STATES
   ============================================ */

.luna-empty {
  text-align: center;
  padding: var(--luna-space-8);
  color: var(--luna-text-secondary);
}

.luna-empty-icon {
  font-size: 3rem;
  margin-bottom: var(--luna-space-4);
  opacity: 0.5;
}

.luna-empty-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--luna-text);
  margin: 0 0 var(--luna-space-2) 0;
}

.luna-empty-description {
  font-size: 0.9375rem;
  margin: 0 0 var(--luna-space-6) 0;
  max-width: 400px;
  margin-left: auto;
  margin-right: auto;
}

/* ============================================
   TWO-COLUMN LAYOUT
   ============================================ */

.luna-layout-sidebar {
  display: flex;
  min-height: 100vh;
}

.luna-layout-sidebar .luna-main {
  flex: 1;
  min-width: 0;
}

/* ============================================
   RESPONSIVE NAVIGATION
   ============================================ */

.luna-mobile-nav-toggle {
  display: none;
}

@media (max-width: 768px) {
  .luna-sidebar {
    position: fixed;
    left: -280px;
    transition: left 0.3s ease;
    z-index: 200;
  }

  .luna-sidebar.open {
    left: 0;
  }

  .luna-sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 199;
  }

  .luna-sidebar.open + .luna-sidebar-overlay {
    display: block;
  }

  .luna-mobile-nav-toggle {
    display: block;
  }

  .luna-header-nav {
    display: none;
  }
}

/* ============================================
   BREADCRUMBS
   ============================================ */

.luna-breadcrumbs {
  display: flex;
  align-items: center;
  gap: var(--luna-space-2);
  font-size: 0.875rem;
  color: var(--luna-text-secondary);
}

.luna-breadcrumb {
  color: var(--luna-text-secondary);
  text-decoration: none;
}

.luna-breadcrumb:hover {
  color: var(--luna-primary);
}

.luna-breadcrumb-separator {
  color: var(--luna-text-tertiary);
}

.luna-breadcrumb-current {
  color: var(--luna-text);
  font-weight: 500;
}

/* ============================================
   PAGE HEADER
   ============================================ */

.luna-page-header {
  margin-bottom: var(--luna-space-6);
}

.luna-page-title {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -1px;
  color: var(--luna-text);
  margin: 0 0 var(--luna-space-2) 0;
}

.luna-page-subtitle {
  font-size: 1rem;
  color: var(--luna-text-secondary);
  margin: 0;
}

.luna-page-actions {
  display: flex;
  gap: var(--luna-space-3);
  margin-top: var(--luna-space-4);
}