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

:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #dbeafe;
  --success: #16a34a;
  --success-light: #dcfce7;
  --warning: #f59e0b;
  --warning-light: #fef3c7;
  --danger: #dc2626;
  --danger-light: #fee2e2;
  --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;
  --radius: 8px;
  --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(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.06);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  color: var(--gray-800);
  background-color: var(--gray-50);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.header {
  background: white;
  border-bottom: 1px solid var(--gray-200);
  padding: 0 1.5rem;
  height: 60px;
  display: flex;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
}

.header-container {
  display: flex;
  align-items: center;
  width: 100%;
  max-width: 1400px;
  margin: 0 auto;
}

.header-logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--gray-900);
  text-decoration: none;
  margin-right: 2rem;
}

.header-nav {
  display: flex;
  gap: 0.25rem;
}

.header-nav a {
  padding: 0.5rem 1rem;
  color: var(--gray-600);
  text-decoration: none;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 500;
  transition: all 0.15s;
}

.header-nav a:hover {
  background: var(--gray-100);
  color: var(--gray-900);
}

.header-nav a.active {
  background: var(--primary-light);
  color: var(--primary);
}

.header-user {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 1rem;
  font-size: 0.9rem;
  color: var(--gray-600);
}

.btn-logout {
  color: var(--gray-500);
  text-decoration: none;
  font-size: 0.85rem;
}

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

.main-content {
  flex: 1;
  padding: 2rem 1.5rem;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
}

h1 {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: 0.5rem;
}

.subtitle {
  color: var(--gray-500);
  margin-bottom: 2rem;
}

.dashboard-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
  margin-top: 1rem;
}

.card {
  background: white;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
  transition: all 0.2s;
  cursor: pointer;
}

.card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.card-icon {
  font-size: 2rem;
  margin-bottom: 0.75rem;
}

.card-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--gray-800);
  margin-bottom: 0.25rem;
}

.card-desc {
  font-size: 0.85rem;
  color: var(--gray-500);
}

.login-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--gray-50) 0%, var(--primary-light) 100%);
}

.login-box {
  background: white;
  padding: 2.5rem;
  border-radius: 12px;
  box-shadow: var(--shadow-md);
  width: 100%;
  max-width: 400px;
  text-align: center;
}

.login-logo {
  font-size: 3rem;
  margin-bottom: 0.5rem;
}

.login-box h1 {
  font-size: 1.5rem;
  margin-bottom: 0.25rem;
}

.login-subtitle {
  color: var(--gray-500);
  font-size: 0.9rem;
  margin-bottom: 2rem;
}

.login-form {
  text-align: left;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--gray-700);
  margin-bottom: 0.4rem;
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 0.6rem 0.85rem;
  border: 1px solid var(--gray-300);
  border-radius: var(--radius);
  font-size: 0.95rem;
  color: var(--gray-800);
  background: white;
  transition: border-color 0.15s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.6rem 1.25rem;
  font-size: 0.9rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  text-decoration: none;
  transition: all 0.15s;
}

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

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

.btn-full {
  width: 100%;
}

.alert {
  padding: 0.75rem 1rem;
  border-radius: var(--radius);
  font-size: 0.9rem;
  margin-bottom: 1.25rem;
}

.alert-error {
  background: var(--danger-light);
  color: var(--danger);
  border: 1px solid #fca5a5;
}

.alert-success {
  background: var(--success-light);
  color: var(--success);
  border: 1px solid #86efac;
}

.error-page {
  text-align: center;
  padding: 4rem 1rem;
}

.error-code {
  font-size: 6rem;
  font-weight: 800;
  color: var(--gray-200);
  line-height: 1;
  margin-bottom: 1rem;
}

.error-page h1 {
  margin-bottom: 0.5rem;
}

.error-page p {
  color: var(--gray-500);
  margin-bottom: 2rem;
}

.footer {
  text-align: center;
  padding: 1.5rem;
  color: var(--gray-400);
  font-size: 0.8rem;
  border-top: 1px solid var(--gray-200);
}

@media (max-width: 768px) {
  .header-nav { display: none; }
  .dashboard-cards { grid-template-columns: 1fr 1fr; }
}

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