:root {
    --primary: #4f46e5;
    --primary-light: #818cf8;
    --primary-dark: #3730a3;
    --secondary: #f97316;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    --radius: 0.5rem;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  }
  
  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    line-height: 1.6;
    color: var(--gray-800);
    background-color: var(--gray-50);
    padding: 1rem;
  }
  
  .container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 2rem;
  }
  
  header {
    text-align: center;
    margin-bottom: 2.5rem;
  }
  
  h1 {
    font-size: 2.25rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 0.75rem;
  }
  
  .subtitle {
    font-size: 1.125rem;
    color: var(--gray-600);
    max-width: 600px;
    margin: 0 auto;
  }
  
  .highlight {
    color: var(--primary);
  }
  
  .calculator-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  
  @media (min-width: 768px) {
    .calculator-grid {
      grid-template-columns: 1fr 1fr;
    }
  }
  
  .card {
    background-color: white;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 1.5rem;
    height: 100%;
  }
  
  .card-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
  }
  
  .card-title svg {
    width: 1.25rem;
    height: 1.25rem;
    color: var(--primary);
  }
  
  .input-group {
    margin-bottom: 1.5rem;
  }
  
  .input-group:last-child {
    margin-bottom: 0;
  }
  
  label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--gray-700);
    margin-bottom: 0.5rem;
  }
  
  .input-wrapper {
    position: relative;
  }
  
  .currency-input {
    padding-left: 1.75rem;
  }
  
  .currency-symbol {
    position: absolute;
    left: 0.25rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--gray-500);
    font-weight: 500;
  }
  
  input[type="text"],
  input[type="number"] {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    font-size: 1rem;
    color: var(--gray-800);
    transition: border-color 0.15s ease;
  }
  
  input[type="text"]:focus,
  input[type="number"]:focus {
    outline: none;
    border-color: var(--primary-light);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
  }
  
  .range-container {
    margin-top: 0.5rem;
  }
  
  .range-slider {
    -webkit-appearance: none;
    width: 100%;
    height: 6px;
    border-radius: 5px;
    background: var(--gray-200);
    outline: none;
    margin: 1rem 0;
  }
  
  .range-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
    box-shadow: 0 0 0 4px rgba(79, 70, 229, 0.1);
  }
  
  .range-slider::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
    border: none;
    box-shadow: 0 0 0 4px rgba(79, 70, 229, 0.1);
  }
  
  .range-labels {
    display: flex;
    justify-content: space-between;
    font-size: 0.75rem;
    color: var(--gray-500);
  }
  
  .range-value {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--primary);
    text-align: center;
    margin-bottom: 0.5rem;
  }
  
  .results-card {
    background-color: white;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 1.5rem;
    margin-top: 2rem;
  }
  
  .results-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
  }
  
  .results-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--gray-800);
  }
  
  .results-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
  }
  
  .result-item {
    background-color: var(--gray-50);
    padding: 1rem;
    border-radius: var(--radius);
  }
  
  .result-label {
    font-size: 0.875rem;
    color: var(--gray-600);
    margin-bottom: 0.25rem;
  }
  
  .result-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--gray-900);
  }
  
  .result-value.highlight {
    color: var(--primary);
  }
  
  .chart-container {
    margin-top: 1.5rem;
    height: 300px;
  }
  
  .btn-group {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
    flex-wrap: wrap;
  }
  
  .btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    border-radius: var(--radius);
    cursor: pointer;
    transition: all 0.15s ease;
    text-decoration: none;
  }
  
  .btn-primary {
    background-color: var(--primary);
    color: white;
    border: none;
  }
  
  .btn-primary:hover {
    background-color: var(--primary-dark);
  }
  
  .btn-secondary {
    background-color: var(--secondary);
    color: white;
    border: none;
  }
  
  .btn-secondary:hover {
    background-color: #ea580c;
  }
  
  @media (max-width: 640px) {
    .container {
      padding: 1rem;
    }
    
    h1 {
      font-size: 1.75rem;
    }
    
    .results-grid {
      grid-template-columns: 1fr;
    }
    
    .btn-group {
      flex-direction: column;
    }
    
    .btn {
      width: 100%;
    }
  }