body {
  margin: 0;
  font-family: 'Segoe UI', sans-serif;
  background: #f7f7f7;
}
.bmi-section {
  max-width: 500px;
  margin: 60px auto;
  background: white;
  padding: 40px;
  border-radius: 16px;
  box-shadow: 0 6px 12px rgba(0,0,0,0.08);
  text-align: center;
}
.bmi-section h1 {
  margin-bottom: 10px;
  color: #8AAAE5;
}
.bmi-section p {
  margin-bottom: 30px;
  color: #666;
}
.input-group {
  margin-bottom: 20px;
  text-align: left;
}
.input-group label {
  display: block;
  margin-bottom: 6px;
  font-weight: 600;
  color: #333;
}
.input-group input {
  width: 100%;
  padding: 10px;
  border: 1px solid #ccc;
  border-radius: 8px;
  font-size: 16px;
}
.btn-calculate {
  padding: 12px 20px;
  background: #8AAAE5;
  border: none;
  color: white;
  font-size: 16px;
  border-radius: 10px;
  cursor: pointer;
  transition: background 0.3s;
}
.btn-calculate:hover {
  background: #5f85db;
}
.result-box {
  margin-top: 30px;
  padding: 20px;
  background: #eef2f9;
  border-radius: 12px;
  display: none;
  text-align: center;
}
.result-box strong {
  color: #8AAAE5;
  font-size: 18px;
}