* {
    box-sizing: border-box;
    font-family: system-ui, sans-serif;
  }
  
  body {
    background: #f3f4f6;
    padding: 20px;
  }
  
  .calculator {
    max-width: 520px;
    margin: auto;
    background: white;
    padding: 24px;
    border-radius: 12px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
  }
  
  h2 {
    text-align: center;
    margin-bottom: 20px;
  }
  
  .section {
    margin-bottom: 20px;
  }
  
  .section h3 {
    font-size: 14px;
    margin-bottom: 8px;
    color: #555;
  }
  
  .row {
    display: flex;
    gap: 10px;
  }
  
  input {
    flex: 1;
    padding: 10px;
    font-size: 16px;
    border-radius: 8px;
    border: 1px solid #ccc;
  }
  
  input[readonly] {
    background: #f9fafb;
    color: #555;
  }
  
  .result input {
    font-weight: bold;
    border-color: #4f46e5;
  }
  
  @media (max-width: 480px) {
    .row {
      flex-direction: column;
    }
  }
  

  .input-group {
    position: relative;
    display: flex;
    align-items: center;
  }
  
  .input-group input {
    width: 100%;
    padding-right: 40px;
  }
  
  .currency {
    position: absolute;
    right: 12px;
    color: #555;
    font-weight: 500;
    pointer-events: none;
  }