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

:root {
  --primary: #2c3e50;
  --secondary: #3498db;
  --accent: #e74c3c;
  --success: #27ae60;
  --light: #ecf0f1;
  --gray: #95a5a6;
  --border: #bdc3c7;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: #f5f5f5;
  color: var(--primary);
}

.container {
  max-width: 1400px;
  margin: 0 auto;
}

/* Header */
.header {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  color: white;
  padding: 2rem;
  text-align: center;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.header h1 {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
}

.header p {
  font-size: 1.1rem;
  opacity: 0.9;
}

/* Navigation */
.nav {
  display: flex;
  gap: 0.5rem;
  padding: 1rem;
  background-color: white;
  border-bottom: 2px solid var(--light);
  overflow-x: auto;
  flex-wrap: wrap;
}

.nav-btn {
  padding: 0.75rem 1.5rem;
  border: none;
  background-color: var(--light);
  color: var(--primary);
  cursor: pointer;
  border-radius: 4px;
  font-weight: 500;
  transition: all 0.3s ease;
  white-space: nowrap;
}

.nav-btn:hover {
  background-color: var(--secondary);
  color: white;
}

.nav-btn.active {
  background-color: var(--secondary);
  color: white;
  box-shadow: 0 2px 8px rgba(52, 152, 219, 0.3);
}

/* Main Content */
.main {
  padding: 2rem;
}

.section {
  display: none;
  background-color: white;
  border-radius: 8px;
  padding: 2rem;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  animation: fadeIn 0.3s ease-in;
}

.section.active {
  display: block;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.section h2 {
  color: var(--primary);
  margin-bottom: 1.5rem;
  border-bottom: 3px solid var(--secondary);
  padding-bottom: 0.5rem;
}

.section h3 {
  color: var(--primary);
  margin-top: 1.5rem;
  margin-bottom: 1rem;
}

/* Forms */
.form-section {
  background-color: #f9f9f9;
  padding: 1.5rem;
  border-radius: 6px;
  margin-bottom: 2rem;
  border-left: 4px solid var(--secondary);
}

form {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
  margin-bottom: 1rem;
}

input, select {
  padding: 0.75rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 1rem;
  font-family: inherit;
  transition: border-color 0.3s;
}

input:focus, select:focus {
  outline: none;
  border-color: var(--secondary);
  box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
}

/* Buttons */
.btn {
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: 4px;
  font-size: 1rem;
  cursor: pointer;
  transition: all 0.3s ease;
  font-weight: 600;
}

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

.btn-primary:hover {
  background-color: #2980b9;
  box-shadow: 0 4px 12px rgba(52, 152, 219, 0.3);
}

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

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

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

.btn-danger:hover {
  background-color: #c0392b;
}

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

.btn-success:hover {
  background-color: #229954;
}

/* Tables */
.list-section {
  margin-top: 2rem;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1rem;
}

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

th {
  padding: 1rem;
  text-align: left;
  font-weight: 600;
}

td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--light);
}

tbody tr:hover {
  background-color: #f9f9f9;
}

tbody tr:nth-child(even) {
  background-color: #fafafa;
}

/* Stats Grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.stat-card {
  background: linear-gradient(135deg, var(--secondary), #2980b9);
  color: white;
  padding: 1.5rem;
  border-radius: 8px;
  text-align: center;
  box-shadow: 0 4px 12px rgba(52, 152, 219, 0.3);
}

.stat-card h3 {
  font-size: 0.9rem;
  opacity: 0.9;
  margin: 0;
  text-transform: uppercase;
}

.stat-number {
  font-size: 2.5rem;
  font-weight: bold;
  margin: 0.5rem 0;
}

/* Quick Actions */
.quick-actions {
  background-color: #f9f9f9;
  padding: 1.5rem;
  border-radius: 6px;
  border-left: 4px solid var(--success);
}

.quick-actions h3 {
  margin-top: 0;
}

.quick-actions {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.quick-actions .btn {
  width: 100%;
  text-align: center;
}

/* Filters */
.filters {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1rem;
  flex-wrap: wrap;
}

.filters .btn {
  flex: 1;
  min-width: 120px;
}

/* Reports */
.report-container {
  margin-top: 1rem;
}

.report-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}

.report-card {
  background: linear-gradient(135deg, var(--light), #ddd);
  padding: 1.5rem;
  border-radius: 8px;
  text-align: center;
  border-top: 4px solid var(--secondary);
}

.report-card span {
  display: block;
  font-size: 0.9rem;
  color: var(--gray);
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}

.report-number {
  font-size: 2rem;
  font-weight: bold;
  color: var(--primary);
  margin: 0;
}

/* Recent Operations */
.recent-ops {
  background-color: #f9f9f9;
  border-radius: 6px;
  padding: 1rem;
  max-height: 400px;
  overflow-y: auto;
}

.op-item {
  padding: 0.75rem;
  border-left: 4px solid var(--secondary);
  margin-bottom: 0.5rem;
  background-color: white;
  border-radius: 4px;
}

.op-item span {
  display: block;
  font-size: 0.85rem;
  color: var(--gray);
  margin-top: 0.25rem;
}

/* Status Badges */
.status-badge {
  display: inline-block;
  padding: 0.35rem 0.75rem;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
}

.status-available {
  background-color: #d4edda;
  color: #155724;
}

.status-occupied {
  background-color: #f8d7da;
  color: #721c24;
}

.status-confirmed {
  background-color: #d1ecf1;
  color: #0c5460;
}

.status-checked-in {
  background-color: #d4edda;
  color: #155724;
}

.status-checked-out {
  background-color: #e2e3e5;
  color: #383d41;
}

/* Responsive */
@media (max-width: 768px) {
  .header h1 {
    font-size: 1.8rem;
  }

  .nav {
    flex-direction: column;
  }

  .nav-btn {
    width: 100%;
  }

  form {
    grid-template-columns: 1fr;
  }

  table {
    font-size: 0.9rem;
  }

  th, td {
    padding: 0.5rem;
  }

  .stat-card h3 {
    font-size: 0.75rem;
  }

  .stat-number {
    font-size: 1.8rem;
  }
}