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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  background-color: #f5f5f5;
  color: #333;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.container {
  background: white;
  padding: 2rem;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  text-align: center;
  max-width: 600px;
  width: 90%;
}

h1 {
  margin-bottom: 2rem;
  color: #333;
}

.demo-section {
  margin-bottom: 3rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid #eee;
}

.demo-section:last-child {
  border-bottom: none;
  margin-bottom: 0;
}

h2 {
  font-size: 1.2rem;
  margin-bottom: 1rem;
  color: #555;
}

button {
  background-color: #0066cc;
  color: white;
  border: none;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  border-radius: 4px;
  cursor: pointer;
  transition: background-color 0.2s;
}

button:hover {
  background-color: #0052a3;
}

button:active {
  background-color: #003d7a;
}

.api-response {
  margin-top: 2rem;
  min-height: 200px;
}

.api-response:empty::before {
  content: "API response will appear here...";
  color: #999;
  font-style: italic;
  display: block;
  padding: 2rem;
  text-align: center;
}

.loading {
  padding: 2rem;
  text-align: center;
  color: #0066cc;
  font-weight: 500;
}

.response-card {
  background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
  border: 2px solid #e9ecef;
  border-radius: 12px;
  padding: 1.5rem;
  text-align: left;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.response-header {
  text-align: center;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid #e9ecef;
}

.response-header h3 {
  color: #0066cc;
  font-size: 1.1rem;
  font-weight: 600;
  margin: 0;
}

.info-section {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.info-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 1rem;
  background: white;
  border-radius: 8px;
  border: 1px solid #e9ecef;
  transition: all 0.2s;
}



.info-label {
  font-weight: 500;
  color: #495057;
  font-size: 0.95rem;
}

.info-value {
  font-weight: 600;
  color: #0066cc;
  font-size: 0.95rem;
  text-align: right;
}

.response-footer {
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid #e9ecef;
  text-align: center;
}

.response-footer small {
  color: #6c757d;
  font-size: 0.85rem;
}

.error-message {
  padding: 1.5rem;
  background-color: #fff5f5;
  border: 2px solid #fed7d7;
  border-radius: 8px;
  color: #c53030;
  text-align: center;
  font-weight: 500;
}

.calculator {
  margin-top: 1rem;
}

.input-group {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
  flex-wrap: wrap;
}

.input-group input {
  padding: 0.75rem;
  font-size: 1rem;
  border: 1px solid #ddd;
  border-radius: 4px;
  width: 120px;
  text-align: center;
}

.input-group input:focus {
  outline: none;
  border-color: #0066cc;
  box-shadow: 0 0 0 2px rgba(0, 102, 204, 0.1);
}

.input-group select {
  padding: 0.75rem;
  font-size: 1.2rem;
  border: 1px solid #ddd;
  border-radius: 4px;
  background: white;
  cursor: pointer;
  font-weight: bold;
  min-width: 60px;
}

.input-group select:focus {
  outline: none;
  border-color: #0066cc;
  box-shadow: 0 0 0 2px rgba(0, 102, 204, 0.1);
}

#calcOutput {
  margin-top: 1rem;
  padding: 1rem;
  background-color: #f9f9f9;
  border: 1px solid #ddd;
  border-radius: 4px;
  text-align: center;
  min-height: 60px;
  white-space: pre-wrap;
  word-wrap: break-word;
  font-family: 'Courier New', monospace;
  font-size: 1.1rem;
  font-weight: bold;
  color: #0066cc;
  display: flex;
  align-items: center;
  justify-content: center;
}

#calcOutput:empty::before {
  content: "Result will appear here...";
  color: #999;
  font-style: italic;
  font-weight: normal;
}