body {
  font-family: "Microsoft JhengHei", sans-serif;
  background-color: #f5f5f5;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 40px;
  padding: 40px;
}

.button-group {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 16px;
}

.btn {
  padding: 12px 20px;
  border: 2px solid #4B00FF;
  border-radius: 8px;
  color: #4B00FF;
  background-color: white;
  font-size: 18px;
  cursor: pointer;
  transition: all 0.3s;
}

.btn:hover {
  background-color: #4B00FF;
  color: white;
}

.dropdown {
  position: relative;
  display: inline-block;
}

.dropbtn {
  background-color: #ffffff;
  color: #4B00FF;
  padding: 12px 16px;
  font-size: 16px;
  border: 2px solid #4B00FF;
  border-radius: 8px;
  cursor: pointer;
}

.dropdown-content {
  display: none;
  position: absolute;
  background-color: white;
  border: 1px solid #ccc;
  min-width: 220px;
  border-radius: 8px;
  box-shadow: 0 8px 16px rgba(0,0,0,0.15);
  z-index: 1;
  margin-top: 5px;
}

.dropdown-content a {
  color: #333;
  padding: 12px 16px;
  text-decoration: none;
  display: block;
  transition: background 0.2s;
}

.dropdown-content a:hover {
  background-color: #f1f1f1;
}

.dropdown:hover .dropdown-content {
  display: block;
}


.hint {
  background-color: #f9f9f9;
  padding: 10px 15px;
  border-left: 4px solid #FF0000;
  color: #333;
  margin-top: 20px;
  font-size: 14px;
}