.booster-tool-container {
  max-width: 700px;
  margin: 30px auto;
  padding: 20px;
  border: 2px solid #eee;
  border-radius: 12px;
  background: #fff;
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
  font-family: Arial, sans-serif;
}

.booster-tool-container h2 {
  text-align: center;
  font-size: 1.6rem;
  margin-bottom: 15px;
  color: #333;
}

.booster-tool-container label {
  font-weight: bold;
  margin-right: 10px;
}

.booster-tool-container select {
  padding: 8px 12px;
  border-radius: 8px;
  border: 1px solid #ccc;
  font-size: 1rem;
}

#diagram-container {
  margin-top: 20px;
  text-align: center;
  min-height: 300px;
}

.diagram-svg {
  max-width: 100%;
  height: auto;
}

.fade-in {
  animation: fadeIn 0.8s ease-in-out;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

#recommendation {
  margin-top: 20px;
  padding: 15px;
  border-top: 1px solid #ddd;
  font-size: 1rem;
  color: #444;
  background: #f9f9f9;
  border-radius: 8px;
}