:root {
  --primary-color: #3498db;
  --secondary-color: #2980b9;
  --accent-color: #e74c3c;
  --background-color: #ecf0f1;
  --text-color: #2c3e50;
  --light-color: #ffffff;
  --dark-color: #34495e;
  --success-color: #2ecc71;
  --warning-color: #f39c12;
  --error-color: #e74c3c;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
  background-color: var(--background-color);
  color: var(--text-color);
  line-height: 1.6;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px;
}

/* Header Styles */
.header {
  background-color: var(--primary-color);
  color: var(--light-color);
  padding: 20px 0;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.header .logo {
  font-size: 24px;
  font-weight: bold;
}

.header .nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.header .nav-links {
  display: flex;
  list-style: none;
}

.header .nav-links li {
  margin-left: 20px;
}

.header .nav-links a {
  color: var(--light-color);
  text-decoration: none;
  transition: all 0.3s ease;
}

.header .nav-links a:hover {
  opacity: 0.8;
}

/* Form Styles */
.form-container {
  background-color: var(--light-color);
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  padding: 30px;
  max-width: 500px;
  margin: 40px auto;
}

.form-title {
  text-align: center;
  margin-bottom: 20px;
  color: var(--primary-color);
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  margin-bottom: 8px;
  font-weight: 500;
}

.form-control {
  width: 100%;
  padding: 12px;
  border: 1px solid #ddd;
  border-radius: 4px;
  font-size: 16px;
  transition: border 0.3s ease;
}

.form-control:focus {
  border-color: var(--primary-color);
  outline: none;
}

.btn {
  display: inline-block;
  background-color: var(--primary-color);
  color: var(--light-color);
  border: none;
  padding: 12px 20px;
  border-radius: 4px;
  font-size: 16px;
  cursor: pointer;
  transition: all 0.3s ease;
}

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

.btn-block {
  display: block;
  width: 100%;
}

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

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

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

.btn-success:hover {
  background-color: #27ae60;
}

/* Dashboard Styles */
.dashboard {
  background-color: var(--light-color);
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  padding: 30px;
  margin: 40px auto;
}

.dashboard-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 30px;
}

.dashboard-stats {
  display: flex;
  justify-content: space-between;
  margin-bottom: 30px;
}

.stat-card {
  background-color: var(--background-color);
  border-radius: 8px;
  padding: 20px;
  flex: 1;
  margin: 0 10px;
  text-align: center;
  box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

.stat-card h3 {
  margin-bottom: 10px;
  color: var(--primary-color);
}

.stat-card .value {
  font-size: 28px;
  font-weight: bold;
}

/* Table Styles */
.table-container {
  overflow-x: auto;
}

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

table th, table td {
  padding: 12px 15px;
  text-align: left;
  border-bottom: 1px solid #ddd;
}

table th {
  background-color: var(--primary-color);
  color: var(--light-color);
}

table tr:hover {
  background-color: rgba(0,0,0,0.02);
}

/* Alert Styles */
.alert {
  padding: 15px;
  border-radius: 4px;
  margin-bottom: 20px;
}

.alert-success {
  background-color: #d4edda;
  color: #155724;
  border: 1px solid #c3e6cb;
}

.alert-danger {
  background-color: #f8d7da;
  color: #721c24;
  border: 1px solid #f5c6cb;
}

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

  .header .nav-links {
    margin-top: 15px;
  }

  .dashboard-stats {
    flex-direction: column;
  }

  .stat-card {
    margin: 10px 0;
  }
}