* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Arial, sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background: #f5f5f7;
  padding: 20px;
}

.container {
  width: 100%;
  max-width: 600px;
}

.calculator-card {
  background: rgba(255, 255, 255, 0.95);
  padding: 2rem;
  border-radius: 20px;
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.08);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}

h1 {
  color: #1e293b;
  font-size: 2rem;
  text-align: center;
  margin-bottom: 0.5rem;
}

.subtitle {
  color: #64748b;
  text-align: center;
  margin-bottom: 2rem;
}

.form-row {
  display: flex;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.form-group {
  flex: 1;
}

label {
  display: block;
  color: #1d1d1f;
  font-weight: 500;
  margin-bottom: 0.5rem;
}

.info-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: #e8e8ed;
  color: #007AFF;
  font-size: 12px;
  cursor: help;
}

input, select {
  width: 100%;
  padding: 0.75rem;
  border: 2px solid #e2e8f0;
  border-radius: 12px;
  font-size: 1rem;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  background: white;
  -webkit-appearance: none;
  appearance: none;
}

input:focus, select:focus {
  outline: none;
  border-color: #007AFF;
  box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.1);
}

.height-group {
  flex: 1;
}

.height-unit-selector {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
}

.unit-btn {
  flex: 1;
  padding: 0.75rem;
  border: 2px solid #e2e8f0;
  border-radius: 12px;
  background: white;
  color: #64748b;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  font-weight: 500;
}

.unit-btn.active {
  background: #007AFF;
  color: white;
  border-color: #007AFF;
}

.height-inputs {
  display: flex;
  gap: 0.5rem;
}

.factors-btn {
  width: 100%;
  padding: 1rem;
  margin: 1.5rem 0;
  border: none;
  border-radius: 8px;
  background: #F2F2F7;
  color: #007AFF;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  transition: all 0.2s;
}

.factors-btn:hover {
  background: #E5E5EA;
}

.dropdown-icon {
  font-size: 0.8rem;
}

.calculate-btn {
  width: 100%;
  padding: 1rem;
  border: none;
  border-radius: 12px;
  background: #007AFF;
  color: white;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  transition: all 0.2s;
  margin-top: 1.5rem;
  -webkit-tap-highlight-color: transparent;
}

.calculate-btn:hover {
  background: #0066CC;
  transform: scale(0.98);
}

.calc-icon {
  font-size: 1.2rem;
}

.results-section {
  margin-top: 2rem;
  padding: 1.5rem;
  background: #F2F2F7;
  border-radius: 12px;
  box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.05);
}

.disclaimer {
  margin-top: 1.5rem;
  text-align: center;
  color: #8E8E93;
  font-size: 0.875rem;
}

.bmi-result {
  text-align: center;
  margin: 1.5rem 0;
}

.bmi-value {
  font-size: 3rem;
  font-weight: bold;
  color: #007AFF;
}

.bmi-category {
  font-size: 1.5rem;
  font-weight: 500;
  margin-top: 0.5rem;
}

.bmi-scale {
  margin: 2rem 0;
}

.scale-bar {
  position: relative;
  height: 8px;
  background: linear-gradient(to right, #64D2FF, #30B0C7, #FF9500, #FF3B30);
  border-radius: 4px;
  margin-bottom: 1rem;
}

.scale-marker {
  position: absolute;
  width: 16px;
  height: 16px;
  background: #1C1C1E;
  border: 3px solid white;
  border-radius: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.scale-segments {
  display: flex;
  justify-content: space-between;
  color: #8E8E93;
  font-size: 0.875rem;
}

.health-insights {
  margin-top: 2rem;
  padding: 1.5rem;
  background: white;
  border-radius: 12px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.health-insights h3 {
  color: #1C1C1E;
  margin-bottom: 1rem;
}

.health-insights ul {
  list-style-type: none;
  padding: 0;
  margin: 0;
}

.health-insights li {
  margin-bottom: 0.75rem;
  color: #3A3A3C;
  padding-left: 1.5rem;
  position: relative;
}

.health-insights li::before {
  content: '•';
  position: absolute;
  left: 0.5rem;
  color: #007AFF;
}