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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  padding: 40px 20px;
}

.container {
  max-width: 800px;
  margin: 0 auto;
}

.card {
  background: white;
  border-radius: 12px;
  padding: 40px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

h1 {
  color: #1f2937;
  margin-bottom: 8px;
  font-size: 32px;
}

h2 {
  color: #4b5563;
  margin-bottom: 16px;
  font-size: 24px;
}

.dropdown-group {
  margin-bottom: 16px;
}

.dropdown-header {
  background: #f3f4f6;
  padding: 12px 16px;
  border-radius: 6px;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 500;
  color: #374151;
  transition: background 0.2s;
}

.dropdown-header:hover {
  background: #e5e7eb;
}

.dropdown-arrow {
  transition: transform 0.3s;
  font-size: 12px;
}

.dropdown-content {
  padding-left: 16px;
  margin-top: 8px;
}

a {
  display: block;
  color: #667eea;
  text-decoration: none;
  padding: 12px 16px;
  border-radius: 6px;
  transition: background 0.2s;
  margin-bottom: 8px;
}

a:hover {
  background: #f3f4f6;
}