* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --primary: #007AFF;
  --primary-dark: #0051D5;
  --danger: #FF3B30;
  --success: #34C759;
  --warning: #FF9500;
  --gray-100: #F9FAFB;
  --gray-200: #EEEFF2;
  --gray-300: #D0D5DD;
  --gray-400: #98A2B3;
  --gray-500: #626D7B;
  --gray-600: #344152;
  --gray-700: #1A1D24;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--gray-100);
  color: var(--gray-700);
  line-height: 1.5;
}

.container {
  display: flex;
  height: 100vh;
  flex-direction: column;
}

/* Navbar */
.navbar {
  background: white;
  border-bottom: 1px solid var(--gray-200);
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}

.navbar-brand {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
}

.navbar-menu {
  display: flex;
  gap: 1rem;
  align-items: center;
}

/* Admin Container */
.admin-container {
  display: flex;
  flex: 1;
  overflow: hidden;
}

/* Sidebar */
.sidebar {
  width: 240px;
  background: white;
  border-right: 1px solid var(--gray-200);
  overflow-y: auto;
  padding: 1rem 0;
}

.nav-menu {
  list-style: none;
}

.nav-link {
  display: block;
  padding: 0.75rem 1.5rem;
  color: var(--gray-500);
  text-decoration: none;
  transition: all 0.2s;
  border-left: 3px solid transparent;
}

.nav-link:hover {
  background: var(--gray-100);
  color: var(--gray-700);
}

.nav-link.active {
  background: var(--primary);
  color: white;
  border-left-color: var(--primary);
}

/* Main Content */
.main-content {
  flex: 1;
  overflow-y: auto;
  padding: 2rem;
}

.page {
  display: none;
}

.page.active {
  display: block;
}

.page h1 {
  margin-bottom: 1.5rem;
  font-size: 2rem;
  color: var(--gray-700);
}

/* Stats Grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.stat-card {
  background: white;
  padding: 1.5rem;
  border-radius: 8px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 0.5rem;
}

.stat-label {
  font-size: 0.875rem;
  color: var(--gray-500);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* Controls */
.controls {
  margin-bottom: 1.5rem;
  display: flex;
  gap: 0.5rem;
}

/* Table */
.table {
  width: 100%;
  border-collapse: collapse;
  background: white;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.table thead {
  background: var(--gray-100);
  border-bottom: 1px solid var(--gray-200);
}

.table th {
  padding: 1rem;
  text-align: left;
  font-weight: 600;
  color: var(--gray-600);
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.table td {
  padding: 1rem;
  border-bottom: 1px solid var(--gray-200);
  font-size: 0.9375rem;
}

.table tbody tr:hover {
  background: var(--gray-100);
}

.table tbody tr:last-child td {
  border-bottom: none;
}

.loading {
  text-align: center;
  color: var(--gray-400);
  padding: 2rem !important;
}

/* Buttons */
.btn {
  padding: 0.5rem 1rem;
  border: none;
  border-radius: 6px;
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
  background: var(--primary-dark);
}

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

.btn-danger:hover:not(:disabled) {
  background: #E63935;
}

.btn-block {
  width: 100%;
}

/* Login */
.login-container {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
}

.login-card {
  background: white;
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
  width: 100%;
  max-width: 400px;
}

.login-card h1 {
  margin-bottom: 0.5rem;
  color: var(--primary);
}

.login-card p {
  margin-bottom: 1.5rem;
  color: var(--gray-500);
  font-size: 0.9375rem;
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 600;
  color: var(--gray-600);
  font-size: 0.875rem;
}

.form-group input {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid var(--gray-300);
  border-radius: 6px;
  font-size: 0.9375rem;
  transition: all 0.2s;
}

.form-group input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.1);
}

.error {
  background: #FEE;
  color: var(--danger);
  padding: 0.75rem;
  border-radius: 6px;
  margin-bottom: 1rem;
  font-size: 0.875rem;
}

/* Utilities */
.hidden {
  display: none;
}

/* Responsive */
@media (max-width: 768px) {
  .admin-container {
    flex-direction: column;
  }

  .sidebar {
    width: 100%;
    border-right: none;
    border-bottom: 1px solid var(--gray-200);
  }

  .nav-menu {
    display: flex;
    overflow-x: auto;
  }

  .nav-link {
    padding: 0.75rem 1rem;
    white-space: nowrap;
  }

  .main-content {
    padding: 1rem;
  }

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

  .table {
    font-size: 0.8rem;
  }

  .table th,
  .table td {
    padding: 0.5rem;
  }
}