.app-shell {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: 0 var(--space-5);
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.app-brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 700;
  font-size: var(--font-size-base);
  color: var(--text-primary);
  white-space: nowrap;
  text-decoration: none;
}

.app-brand:hover {
  text-decoration: none;
}

.app-brand-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
}

.app-header-search {
  flex: 1;
  max-width: 380px;
  position: relative;
}

.app-header-search input {
  width: 100%;
  height: 36px;
  padding: 0 var(--space-4);
  padding-left: 2.25rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--background);
  color: var(--text-primary);
  font-size: var(--font-size-sm);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.app-header-search input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-subtle);
}

.app-header-search input::placeholder {
  color: var(--text-muted);
}

.search-icon {
  position: absolute;
  left: var(--space-3);
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
  display: flex;
  align-items: center;
}

.app-header-links {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.app-header-link {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.6rem;
  border-radius: var(--radius-md);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--transition), background var(--transition);
}

.app-header-link:hover {
  color: var(--text-primary);
  background: var(--surface-elevated, rgba(255,255,255,0.04));
}

.app-header-link[hidden] {
  display: none !important;
}

.app-header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-left: auto;
}

.icon-btn[hidden] {
  display: none !important;
}

.icon-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  background: transparent;
  border: none;
  cursor: pointer;
  transition: background var(--transition), color var(--transition);
}

.icon-btn:hover {
  background: var(--surface-hover);
  color: var(--text-primary);
}

.icon-btn:active {
  transform: scale(0.96);
}

.offline-status-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  color: var(--text-secondary);
}

.app-body {
  display: flex;
  flex: 1;
}

/* Navigation Groups */
.app-nav {
  position: sticky;
  top: var(--header-height);
  align-self: flex-start;
  width: var(--nav-width);
  flex-shrink: 0;
  max-height: calc(100vh - var(--header-height));
  padding: var(--space-3) var(--space-3);
  padding-bottom: var(--space-2);
  background: var(--surface);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  overscroll-behavior: contain;
  display: flex;
  flex-direction: column;
}

.nav-group {
  margin-bottom: var(--space-1);
}

.nav-group-toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: var(--space-2) var(--space-3);
  border: none;
  border-radius: var(--radius-md);
  background: transparent;
  color: var(--text-muted);
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: color var(--transition), background var(--transition);
}

.nav-group-toggle:hover {
  color: var(--text-secondary);
  background: var(--surface-hover);
}

.nav-group-toggle[aria-expanded='false'] .nav-group-chevron {
  transform: rotate(-90deg);
}

.nav-group-chevron {
  transition: transform var(--transition);
  flex-shrink: 0;
}

/* Nav links always visible — JS may try to hide them, but CSS wins */
.nav-link[data-view],
.nav-group-toggle {
  display: flex !important;
}

.nav-group-items {
  flex-direction: column;
  padding: var(--space-1) 0;
}

.nav-link {
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-3);
  margin: 0 var(--space-1);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-weight: 500;
  font-size: var(--font-size-sm);
  transition: background var(--transition), color var(--transition);
  text-decoration: none;
  position: relative;
}

.nav-link:hover {
  background: var(--surface-hover);
  color: var(--text-primary);
  text-decoration: none;
}

.nav-link.active {
  background: var(--primary-subtle);
  color: var(--primary);
}

.nav-link.active::before {
  content: '';
  position: absolute;
  left: 0;
  top: 6px;
  bottom: 6px;
  width: 3px;
  background: var(--primary);
  border-radius: var(--radius-full);
}

.nav-link-icon {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Ensure clicks on SVG icons inside nav links/buttons pass through to the parent element */
.nav-link svg,
.nav-link i,
.nav-footer-link svg,
.nav-footer-link i,
.icon-btn svg,
.icon-btn i {
  pointer-events: none;
}

/* Nav Footer */
.nav-footer {
  margin-top: auto;
  padding-top: var(--space-4);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
}

.nav-footer-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-md);
  color: var(--text-muted);
  transition: color var(--transition), background var(--transition);
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0;
  font-size: inherit;
}

.nav-footer-link:hover {
  color: var(--text-secondary);
  background: var(--surface-hover);
}

/* Main Content */
.app-main {
  flex: 1;
  padding: var(--space-6);
  overflow-x: hidden;
  background: var(--background);
}

.page-title {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  margin-bottom: var(--space-2);
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

.page-subtitle {
  color: var(--text-muted);
  margin-bottom: var(--space-6);
  max-width: 52rem;
  font-size: var(--font-size-sm);
  line-height: var(--leading-relaxed);
}

/* Icon utilities */
.icon-16 {
  width: 16px;
  height: 16px;
}

.icon-18 {
  width: 18px;
  height: 18px;
}

.icon-20 {
  width: 20px;
  height: 20px;
}

.icon-24 {
  width: 24px;
  height: 24px;
}

/* Grid */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
  margin-bottom: var(--space-6);
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-4);
}

/* Section */
.section-block {
  margin-bottom: var(--space-10);
}

.section-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-5);
}

.section-heading h2 {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--text-primary);
}

/* Mobile */
.mobile-nav-toggle {
  display: none;
}

.mobile-nav-overlay {
  display: none;
}

@media (max-width: 1024px) {
  .grid-3 {
    grid-template-columns: 1fr;
  }

  .grid-2 {
    grid-template-columns: 1fr;
  }

  .app-header-link span {
    display: none;
  }
}

@media (max-width: 768px) {
  .app-header {
    padding: 0 var(--space-4);
  }

  .app-header-search {
    display: none;
  }

  .app-header-links {
    display: none;
  }

  .mobile-nav-toggle {
    display: flex;
  }

  .app-nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    bottom: 0;
    z-index: 90;
    transform: translateX(-100%);
    transition: transform var(--transition-slow) ease;
    box-shadow: var(--shadow-xl);
    width: var(--nav-width);
  }

  .app-nav.open {
    transform: translateX(0);
  }

  .mobile-nav-overlay {
    display: block;
    position: fixed;
    inset: 0;
    top: var(--header-height);
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    z-index: 80;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-slow) ease;
  }

  .mobile-nav-overlay.open {
    opacity: 1;
    pointer-events: auto;
  }

  .app-main {
    padding: var(--space-4);
  }
}