/* ==========================================================================
   Layout Styles - Header, Navigation, Containers, Grid
   ========================================================================== */

/* --------------------------------------------------------------------------
   Header
   -------------------------------------------------------------------------- */
.header {
  background: var(--gradient-primary);
  color: var(--color-white);
  padding: var(--spacing-md) var(--spacing-xl);
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: var(--shadow-lg);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header h1 {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--color-white);
  width: 220px;
  min-width: 220px;
  flex-shrink: 0;
}

/* --------------------------------------------------------------------------
   Navigation
   -------------------------------------------------------------------------- */
.nav-links {
  display: flex;
  gap: var(--spacing-md);
  align-items: center;
}

.nav-links a {
  color: var(--color-white);
  text-decoration: none;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: 5px;
  transition: background var(--transition-base);
  font-weight: 500;
}

.nav-links a:hover,
.nav-links a:focus {
  background: rgba(255, 255, 255, 0.2);
}

.nav-links a.active {
  background: rgba(255, 255, 255, 0.3);
}

/* --------------------------------------------------------------------------
   User Info
   -------------------------------------------------------------------------- */
.user-info {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.user-info span {
  font-size: var(--font-size-base);
}

/* --------------------------------------------------------------------------
   Containers
   -------------------------------------------------------------------------- */
.container {
  max-width: 1400px;
  margin: var(--spacing-xl) auto;
  padding: 0 var(--spacing-xl);
}

.container-sm {
  max-width: 600px;
  margin: var(--spacing-xl) auto;
  padding: 0 var(--spacing-xl);
}

.container-md {
  max-width: 800px;
  margin: var(--spacing-xl) auto;
  padding: 0 var(--spacing-xl);
}

.container-lg {
  max-width: 1200px;
  margin: var(--spacing-xl) auto;
  padding: 0 var(--spacing-xl);
}

/* --------------------------------------------------------------------------
   Grid System
   -------------------------------------------------------------------------- */
.grid {
  display: grid;
  gap: var(--spacing-lg);
}

.grid-2 {
  grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
  grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
  grid-template-columns: repeat(4, 1fr);
}

/* Auto-fit grids */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
}

/* --------------------------------------------------------------------------
   Filter Section
   -------------------------------------------------------------------------- */
.filter-section {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
  box-shadow: var(--shadow-md);
}

.filter-section h3 {
  margin-bottom: var(--spacing-md);
  color: var(--color-gray-800);
}

.filter-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-md);
  align-items: end;
}

/* --------------------------------------------------------------------------
   Action Section
   -------------------------------------------------------------------------- */
.action-section {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-xl);
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.action-buttons {
  display: flex;
  gap: var(--spacing-md);
}

/* --------------------------------------------------------------------------
   Page Sections
   -------------------------------------------------------------------------- */
.section {
  margin-bottom: var(--spacing-xl);
}

.section-title {
  font-size: var(--font-size-xl);
  margin-bottom: var(--spacing-lg);
  color: var(--color-gray-800);
}

/* --------------------------------------------------------------------------
   Login Container (centered form)
   -------------------------------------------------------------------------- */
.login-container {
  max-width: 400px;
  margin: 5rem auto;
  padding: var(--spacing-xl);
  background: var(--color-white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
}

.login-container h2 {
  text-align: center;
  margin-bottom: var(--spacing-xl);
  color: var(--color-gray-800);
}

.login-container .error {
  color: var(--color-danger);
  margin-top: var(--spacing-md);
  text-align: center;
}

.register-link {
  text-align: center;
  margin-top: var(--spacing-md);
}

.register-link a {
  color: var(--color-primary);
}

/* --------------------------------------------------------------------------
   Responsive Styles
   -------------------------------------------------------------------------- */
@media (max-width: 1024px) {
  .header {
    flex-wrap: wrap;
    gap: var(--spacing-md);
  }

  .header h1 {
    width: auto;
    min-width: auto;
  }

  .nav-links {
    order: 3;
    width: 100%;
    justify-content: center;
  }
}

@media (max-width: 768px) {
  .container,
  .container-sm,
  .container-md,
  .container-lg {
    padding: 0 var(--spacing-md);
    margin: var(--spacing-md) auto;
  }

  .header {
    padding: var(--spacing-md);
  }

  .nav-links {
    flex-wrap: wrap;
    gap: var(--spacing-sm);
  }

  .nav-links a {
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: var(--font-size-sm);
  }

  .user-info {
    flex-direction: column;
    align-items: flex-end;
    gap: var(--spacing-sm);
  }

  .filter-row {
    grid-template-columns: 1fr;
  }

  .action-section {
    flex-direction: column;
    align-items: stretch;
  }

  .action-buttons {
    flex-direction: column;
  }

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

  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

  /* Table responsive */
  .data-table th,
  .data-table td {
    padding: 0.75rem;
    font-size: var(--font-size-base);
  }

  .login-container {
    margin: var(--spacing-xl) var(--spacing-md);
  }
}

@media (max-width: 480px) {
  .header h1 {
    font-size: var(--font-size-lg);
  }

  .btn {
    padding: 0.6rem 1rem;
    font-size: var(--font-size-sm);
  }

  .stat-number {
    font-size: var(--font-size-xl);
  }
}