/* Enhanced Calculator Styles */
.calculator-container {
  min-height: 100vh;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.calculator-card {
  background: white;
  border-radius: 16px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
  padding: 30px;
  max-width: 400px;
  width: 100%;
}

.header {
  text-align: center;
  margin-bottom: 30px;
}

.header h2 {
  color: #2c3e50;
  margin: 0 0 15px 0;
  font-size: 28px;
  font-weight: 600;
}

.version-info {
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: #7f8c8d;
  margin-top: 10px;
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: 15px;
}

.number-input, .operation-select {
  padding: 12px 16px;
  border: 2px solid #e1e8ed;
  border-radius: 8px;
  font-size: 16px;
  transition: all 0.3s ease;
  background: #fafbfc;
}

.number-input:focus, .operation-select:focus {
  outline: none;
  border-color: #667eea;
  background: white;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.operation-select {
  cursor: pointer;
}

.calculate-button {
  padding: 14px 24px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  margin-top: 10px;
}

.calculate-button:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(102, 126, 234, 0.3);
}

.calculate-button:disabled {
  background: #bdc3c7;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.result-display {
  margin-top: 20px;
  padding: 15px;
  border-radius: 8px;
  text-align: center;
  font-size: 18px;
  font-weight: 500;
}

.result-display.success {
  background: #d4edda;
  color: #155724;
  border: 1px solid #c3e6cb;
}

.result-display.error {
  background: #f8d7da;
  color: #721c24;
  border: 1px solid #f5c6cb;
}

/* Responsive design */
@media (max-width: 480px) {
  .calculator-container {
    padding: 10px;
  }
  
  .calculator-card {
    padding: 20px;
  }
  
  .header h2 {
    font-size: 24px;
  }
}
