/* ===== CSS Variables ===== */
:root {
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --danger: #ef4444;
  --danger-hover: #dc2626;
  --success: #22c55e;
  --warning: #f59e0b;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  --sidebar-width: 240px;
  --radius: 8px;
  --radius-sm: 6px;
  --shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.1), 0 2px 4px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 15px rgba(0,0,0,0.1), 0 4px 6px rgba(0,0,0,0.05);
}

/* ===== Reset ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  font-size: 14px;
  line-height: 1.5;
  color: var(--gray-900);
  background: var(--gray-50);
}

a {
  text-decoration: none;
  color: inherit;
}

/* ===== Login Screen ===== */
#login-screen {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gray-100);
}

.login-card {
  width: 100%;
  max-width: 400px;
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}

.login-header {
  padding: 2rem 2rem 1rem;
  text-align: center;
}

.login-header h1 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--gray-900);
}

.login-header p {
  color: var(--gray-500);
  font-size: 0.875rem;
  margin-top: 0.25rem;
}

.login-body {
  padding: 1rem 2rem 2rem;
}

.login-error {
  background: #fef2f2;
  color: var(--danger);
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  margin-bottom: 1rem;
}

/* ===== Forms ===== */
.form-group {
  margin-bottom: 1rem;
}

.form-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--gray-700);
  margin-bottom: 0.375rem;
}

.form-input,
.form-select {
  width: 100%;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--gray-300);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  line-height: 1.5;
  color: var(--gray-900);
  background: #fff;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.form-input:focus,
.form-select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.form-input::placeholder {
  color: var(--gray-400);
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.375rem;
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  font-weight: 500;
  line-height: 1.5;
  border: 1px solid var(--gray-300);
  border-radius: var(--radius-sm);
  background: #fff;
  color: var(--gray-700);
  cursor: pointer;
  transition: all 0.15s;
  white-space: nowrap;
}

.btn:hover {
  background: var(--gray-50);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.btn-primary:hover {
  background: var(--primary-hover);
  border-color: var(--primary-hover);
}

.btn-secondary {
  background: var(--gray-600);
  color: #fff;
  border-color: var(--gray-600);
}

.btn-secondary:hover {
  background: var(--gray-700);
  border-color: var(--gray-700);
}

.btn-danger {
  background: var(--danger);
  color: #fff;
  border-color: var(--danger);
}

.btn-danger:hover {
  background: var(--danger-hover);
  border-color: var(--danger-hover);
}

.btn-sm {
  padding: 0.25rem 0.625rem;
  font-size: 0.8125rem;
}

.btn-block {
  width: 100%;
}

/* ===== Sidebar ===== */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: var(--sidebar-width);
  background: var(--gray-900);
  color: #fff;
  display: flex;
  flex-direction: column;
  z-index: 100;
}

.sidebar-header {
  padding: 1.25rem 1rem;
  border-bottom: 1px solid var(--gray-700);
}

.sidebar-header h2 {
  font-size: 1.125rem;
  font-weight: 700;
  color: #fff;
}

.sidebar-subtitle {
  font-size: 0.75rem;
  color: var(--gray-400);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.sidebar-nav {
  list-style: none;
  padding: 0.5rem 0;
  flex: 1;
}

.sidebar-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.625rem 1rem;
  color: var(--gray-300);
  font-size: 0.875rem;
  font-weight: 500;
  transition: all 0.15s;
  border-left: 3px solid transparent;
}

.sidebar-link:hover {
  color: #fff;
  background: rgba(255,255,255,0.05);
}

.sidebar-link.active {
  color: #fff;
  background: rgba(37, 99, 235, 0.15);
  border-left-color: var(--primary);
}

.sidebar-icon {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

.sidebar-footer {
  padding: 0.75rem 1rem;
  border-top: 1px solid var(--gray-700);
}

.sidebar-user {
  font-size: 0.8125rem;
  color: var(--gray-400);
  margin-bottom: 0.5rem;
  padding: 0 0.25rem;
}

.sidebar-logout {
  color: var(--gray-400);
  font-size: 0.8125rem;
}

.sidebar-logout:hover {
  color: var(--danger);
}

/* ===== Main Content ===== */
.main-content {
  margin-left: var(--sidebar-width);
  min-height: 100vh;
  background: #fff;
}

.page-content {
  padding: 2rem;
}

/* ===== Page Header ===== */
.page-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.page-header h1 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--gray-900);
}

.page-header-actions {
  display: flex;
  gap: 0.5rem;
}

/* ===== Cards ===== */
.card {
  background: #fff;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.card-header {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--gray-200);
  font-weight: 600;
  font-size: 0.9375rem;
  color: var(--gray-800);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.card-body {
  padding: 1.25rem;
}

/* ===== Stat Cards ===== */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.stat-card {
  background: #fff;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.25rem;
}

.stat-card .stat-value {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--gray-900);
  line-height: 1.2;
}

.stat-card .stat-label {
  font-size: 0.8125rem;
  color: var(--gray-500);
  margin-top: 0.25rem;
  font-weight: 500;
}

/* ===== Tables ===== */
.table-wrapper {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
}

table th {
  text-align: left;
  padding: 0.75rem 1rem;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--gray-500);
  background: var(--gray-50);
  border-bottom: 1px solid var(--gray-200);
}

table td {
  padding: 0.75rem 1rem;
  font-size: 0.875rem;
  color: var(--gray-700);
  border-bottom: 1px solid var(--gray-100);
}

table tbody tr:nth-child(even) {
  background: var(--gray-50);
}

table tbody tr:hover {
  background: rgba(37, 99, 235, 0.04);
}

table tbody tr.clickable {
  cursor: pointer;
}

/* ===== Badges ===== */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.125rem 0.5rem;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: 9999px;
  line-height: 1.5;
}

.badge-success {
  background: #dcfce7;
  color: #166534;
}

.badge-warning {
  background: #fef3c7;
  color: #92400e;
}

.badge-danger {
  background: #fee2e2;
  color: #991b1b;
}

.badge-info {
  background: #dbeafe;
  color: #1e40af;
}

/* ===== Detail Grid ===== */
.detail-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
}

.detail-item {
  display: flex;
  flex-direction: column;
}

.detail-label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--gray-500);
  margin-bottom: 0.25rem;
}

.detail-value {
  font-size: 0.9375rem;
  color: var(--gray-900);
}

/* ===== Toasts ===== */
.toast-container {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.toast {
  min-width: 280px;
  max-width: 420px;
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  color: #fff;
  box-shadow: var(--shadow-lg);
  animation: toast-in 0.25s ease-out;
}

.toast.toast-out {
  animation: toast-out 0.2s ease-in forwards;
}

.toast-success {
  background: var(--success);
}

.toast-danger {
  background: var(--danger);
}

.toast-warning {
  background: var(--warning);
  color: var(--gray-900);
}

.toast-info {
  background: var(--primary);
}

@keyframes toast-in {
  from { opacity: 0; transform: translateX(40px); }
  to   { opacity: 1; transform: translateX(0); }
}

@keyframes toast-out {
  from { opacity: 1; transform: translateX(0); }
  to   { opacity: 0; transform: translateX(40px); }
}

/* ===== Modal ===== */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  z-index: 500;
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-card {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  width: 100%;
  max-width: 520px;
  max-height: 90vh;
  overflow-y: auto;
  margin: 1rem;
}

.modal-header {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--gray-200);
  font-weight: 600;
  font-size: 1.0625rem;
  color: var(--gray-900);
}

.modal-body {
  padding: 1.25rem;
}

.modal-footer {
  padding: 0.75rem 1.25rem;
  border-top: 1px solid var(--gray-200);
  display: flex;
  justify-content: flex-end;
  gap: 0.5rem;
}

/* ===== Loading Spinner ===== */
.loading {
  text-align: center;
  padding: 3rem;
  color: var(--gray-400);
}

.loading::after {
  content: '';
  display: inline-block;
  width: 24px;
  height: 24px;
  border: 3px solid var(--gray-200);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
  vertical-align: middle;
  margin-left: 0.5rem;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ===== Empty State ===== */
.empty-state {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--gray-400);
}

/* ===== Utilities ===== */
.text-muted {
  color: var(--gray-500);
}

.text-sm {
  font-size: 0.8125rem;
}

.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 1.5rem; }
.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 1.5rem; }

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .sidebar {
    transform: translateX(-100%);
    transition: transform 0.25s ease;
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .main-content {
    margin-left: 0;
  }

  .page-content {
    padding: 1rem;
  }

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

  .page-header {
    flex-direction: column;
    align-items: flex-start;
  }

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

@media (max-width: 480px) {
  .stat-grid {
    grid-template-columns: 1fr;
  }
}