/* App Layout, Navigation Shell, Sidebar & Grid Systems */
.app-container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* Header Navbar */
.site-header {
  height: 64px;
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1.5rem;
  box-shadow: var(--shadow-sm);
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-brand-primary);
}

.brand-icon {
  width: 34px;
  height: 34px;
  background: linear-gradient(135deg, var(--color-brand-primary), var(--color-brand-accent));
  color: #fff;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-link {
  color: var(--color-text-secondary);
  font-weight: 500;
  font-size: 0.925rem;
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.nav-link:hover, .nav-link.active {
  color: var(--color-brand-accent);
  background-color: var(--color-brand-accent-light);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* Dashboard App Layout with Sidebar */
.app-body, .app-layout {
  display: flex;
  flex: 1;
  min-height: calc(100vh - 64px);
}

.app-sidebar {
  width: 260px;
  background-color: var(--color-surface);
  border-right: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  padding: 1.25rem 0.75rem;
  gap: 1.5rem;
  height: calc(100vh - 64px);
  position: sticky;
  top: 64px;
  overflow-y: auto;
}

.sidebar-section-title {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  font-weight: 600;
  padding: 0 0.75rem;
  margin-bottom: 0.5rem;
}

.sidebar-menu {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  list-style: none;
}

.sidebar-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.65rem 0.75rem;
  color: var(--color-text-secondary);
  font-weight: 500;
  font-size: 0.9rem;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.sidebar-link:hover {
  background-color: var(--color-surface-hover);
  color: var(--color-brand-primary);
}

.sidebar-link.active {
  background-color: var(--color-brand-accent-light);
  color: var(--color-brand-accent);
  font-weight: 600;
}

.sidebar-icon {
  font-size: 1.1rem;
  width: 20px;
  text-align: center;
}

.app-main, .app-content {
  flex: 1;
  padding: 2rem;
  max-width: 1600px;
  width: 100%;
  margin: 0 auto;
}

/* Professional Footer */
.site-footer {
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: 3rem 2rem 1.5rem;
  margin-top: auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: 2.5rem;
  max-width: 1200px;
  margin: 0 auto 2.5rem;
}

.footer-brand p {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
  margin-top: 0.75rem;
  line-height: 1.6;
}

.footer-col h4 {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-brand-primary);
  margin-bottom: 1rem;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

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

.footer-links a:hover {
  color: var(--color-brand-accent);
}

.footer-bottom {
  max-width: 1200px;
  margin: 0 auto;
  padding-top: 1.5rem;
  border-top: 1px solid var(--color-divider);
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--color-text-muted);
  font-size: 0.85rem;
}