#simcalcu-heat2d {
  max-width: 400px;
  padding: 20px;
  border: 1px solid #ddd;
  background: #fafafa;
}

#simcalcu-heat2d label {
  display: block;
  margin-top: 10px;
}

#simcalcu-heat2d input,
#simcalcu-heat2d select {
  width: 100%;
  padding: 6px;
  margin-top: 4px;
}

#simcalcu-heat2d button {
  margin-top: 15px;
  width: 100%;
  padding: 10px;
  background: #0073aa;
  color: white;
  border: none;
  cursor: pointer;
}

#simcalcu-heat2d button:hover {
  background: #005f8d;
}

#simcalcu-heat2d {
  max-width: 480px;
  margin: 20px auto;
  padding: 24px;
  border-radius: 12px;
  background: #ffffff;
  box-shadow: 0 4px 18px rgba(0,0,0,0.08);
  font-family: "Hiragino Sans", "Noto Sans JP", sans-serif;
}

#simcalcu-heat2d h3 {
  margin-bottom: 16px;
  font-size: 20px;
  font-weight: 600;
  text-align: center;
  color: #333;
}

#simcalcu-heat2d label {
  display: block;
  margin-top: 14px;
  font-weight: 600;
  color: #444;
}

#simcalcu-heat2d input,
#simcalcu-heat2d select {
  width: 100%;
  padding: 10px;
  margin-top: 6px;
  border: 1px solid #ddd;
  border-radius: 6px;
  font-size: 15px;
}

#simcalcu-heat2d button {
  margin-top: 18px;
  width: 100%;
  padding: 12px;
  background: #0073aa;
  color: white;
  border: none;
  border-radius: 6px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: 0.2s;
}

#simcalcu-heat2d button:hover {
  background: #005f8d;
}

#result, #simscale-status, #simscale-result {
  margin-top: 20px;
  padding: 16px;
  background: #f7f7f7;
  border-radius: 8px;
  font-size: 15px;
  line-height: 1.6;
}