body {
  font-family: Arial, sans-serif;
  margin: 20px;
}

.accordion {
  background-color: #f9f9f9;
  color: #333;
  cursor: pointer;
  padding: 15px;
  width: 100%;
  border: 1px solid #ccc;
  text-align: left;
  outline: none;
  font-size: 16px;
  transition: 0.4s;
  margin-bottom: 5px;
}
.accordion:hover, .accordion.active {
  background-color: #e0e0e0;
}

.panel {
  padding: 0 18px;
  background-color: white;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
  border: 1px solid #ccc;
  border-top: none;
  margin-bottom: 10px;
}

.panel ul {
  margin: 10px 0;
  padding-left: 20px;
}

.sub-accordion {
  background-color: #f0f0f0;
  color: #333;
  cursor: pointer;
  padding: 10px;
  width: 100%;
  border: none;
  text-align: left;
  outline: none;
  font-size: 14px;
  transition: 0.4s;
  margin-top: 5px;
}
.sub-accordion:hover, .sub-accordion.active {
  background-color: #d8d8d8;
}

.sub-panel {
  padding: 0 18px;
  background-color: #fafafa;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
  border-top: 1px solid #ddd;
}