.container-esi-calculator {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  margin: 0;
  background-color: #FFFDEE;
  color: #333333;
}
.container-esi-calculator .calculator-container {
  background-color: #FFFFFF;
  padding: 3rem;
  border-radius: 1.5rem;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
  width: 90%;
  max-width: 400px;
  text-align: center;
}
.container-esi-calculator h1 {
  color: #0A2342;
  font-size: 1.8rem;
  margin-bottom: 1.5rem;
}
.container-esi-calculator label {
  display: block;
  margin-bottom: 0.5rem;
  color: #0A2342;
  font-size: 1rem;
  text-align: left;
  font-weight: 500;
}
.container-esi-calculator input[type=number] {
  width: 100%;
  padding: 0.75rem 1rem;
  margin-bottom: 1.5rem;
  border: 1px solid #dfe6e9;
  border-radius: 0.75rem;
  font-size: 1rem;
  box-sizing: border-box;
  transition: border-color 0.3s ease;
}
.container-esi-calculator input[type=number]:focus {
  outline: none;
  border-color: #de9406;
}
.container-esi-calculator button {
  width: 100%;
  padding: 0.75rem 1rem;
  background-color: #de9406;
  color: #FFFFFF;
  border: none;
  border-radius: 0.75rem;
  font-size: 1rem;
  cursor: pointer;
  transition: background-color 0.3s ease, transform 0.1s ease;
  box-shadow: 0 4px 15px rgba(222, 148, 6, 0.3);
}
.container-esi-calculator button:hover {
  background-color: #c58305;
}
.container-esi-calculator button:active {
  transform: translateY(1px);
}
.container-esi-calculator .result-box {
  margin-top: 2rem;
  padding: 1.5rem;
  background-color: #FFFDF4;
  border-radius: 1rem;
  text-align: left;
  border: 1px solid #f0e9d6;
}
.container-esi-calculator .result-box p {
  margin: 0.5rem 0;
  color: #333333;
  font-size: 1rem;
}
.container-esi-calculator .result-box p span {
  font-weight: bold;
  color: #de8d06;
  float: right;
}
.container-esi-calculator .error-message {
  color: #e74c3c;
  margin-top: 1.5rem;
  font-size: 0.9rem;
  text-align: center;
  font-weight: 500;
}