:root {
  --primary-color: #4a6da7;
  --secondary-color: #6c757d;
  --success-color: #28a745;
  --danger-color: #dc3545;
  --light-color: #f8f9fa;
  --dark-color: #343a40;
  --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  --border-radius: 0.25rem;
  --transition: all 0.3s ease;
}

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

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  background-color: #f5f5f5;
  color: #333;
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px;
}

header {
  text-align: center;
  margin-bottom: 30px;
}

nav {
  display: flex;
  justify-content: center;
  margin-bottom: 20px;
}

nav a {
  display: inline-block;
  padding: 8px 16px;
  margin: 0 5px;
  text-decoration: none;
  color: var(--dark-color);
  background-color: white;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow);
  transition: var(--transition);
}

nav a:hover {
  background-color: var(--primary-color);
  color: white;
}

.container {
  background-color: white;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow);
  padding: 20px;
  margin-bottom: 20px;
}

.form-group {
  margin-bottom: 15px;
}

.form-group label {
  display: block;
  margin-bottom: 5px;
  font-weight: bold;
}

.form-control {
  width: 100%;
  padding: 8px;
  border: 1px solid #ddd;
  border-radius: var(--border-radius);
  font-size: 16px;
}

.btn {
  display: inline-block;
  padding: 8px 16px;
  background-color: var(--primary-color);
  color: white;
  border: none;
  border-radius: var(--border-radius);
  cursor: pointer;
  font-size: 16px;
  transition: var(--transition);
}

.btn:hover {
  opacity: 0.9;
}

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

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

.list-group {
  list-style: none;
  margin-top: 20px;
}

.list-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px;
  border-bottom: 1px solid #ddd;
}

.list-item:last-child {
  border-bottom: none;
}

.points-badge {
  background-color: var(--primary-color);
  color: white;
  padding: 3px 8px;
  border-radius: 10px;
  font-size: 14px;
}

.bank {
  font-size: 24px;
  font-weight: bold;
  padding: 10px;
  background-color: #f8f9fa;
  border-radius: var(--border-radius);
  display: flex;
  justify-content: space-between;
  margin-bottom: 20px;
}

.tasks-container, .rewards-container {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 15px;
  margin-top: 20px;
}

.task-card, .reward-card {
  background-color: white;
  border-radius: var(--border-radius);
  padding: 15px;
  box-shadow: var(--shadow);
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
}

.task-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 10px rgba(0, 0, 0, 0.15);
  background-color: #e8f0fe;
}

.reward-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 10px rgba(0, 0, 0, 0.15);
  background-color: #ffefd5;
}

.table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 20px;
}

.table th, .table td {
  padding: 10px;
  text-align: left;
  border-bottom: 1px solid #ddd;
}

.table th {
  background-color: #f5f5f5;
}

/* Media Queries for Responsive Design */
@media (max-width: 768px) {
  body {
    padding: 10px;
  }
  
  .tasks-container, .rewards-container {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  }
  
  .btn {
    padding: 6px 12px;
    font-size: 14px;
  }
  
  .form-control {
    font-size: 14px;
  }
}

@media (max-width: 480px) {
  nav {
    flex-direction: column;
    align-items: center;
  }
  
  nav a {
    margin: 5px 0;
    width: 100%;
    text-align: center;
  }
  
  .tasks-container, .rewards-container {
    grid-template-columns: 1fr;
  }
  
  .bank {
    flex-direction: column;
    text-align: center;
  }
}