Japanese Zen Garden Scientific Calculator

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Japanese Zen Garden Scientific Calculator</title>
  <style>
    body {
      font-family: 'Arial', sans-serif;
      display: flex;
      justify-content: center;
      align-items: center;
      height: 100vh;
      background-color: #f0f0f0;
      margin: 0;
      color: #333;
    }
    .calculator {
      background-color: #e0e0e0;
      border-radius: 10px;
      box-shadow: 0 0 20px rgba(0, 0, 0, 0.3);
      overflow: hidden;
      width: 300px;
    }
    .screen {
      background-color: #d0d0d0;
      color: #333;
      font-size: 2rem;
      padding: 10px;
      text-align: right;
      word-wrap: break-word;
      overflow-wrap: break-word;
      min-height: 60px;
    }
    .buttons {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
    }
    button {
      background-color: #c0c0c0;
      border: none;
      color: #333;
      cursor: pointer;
      font-size: 1.5rem;
      padding: 20px 0;
      transition: background-color 0.3s ease;
    }
    button:hover {
      background-color: #b0b0b0;
    }
    button.operator {
      background:linear-gradient(#333,#999);
      color: #fff;
    }
    button.special {
      background: linear-gradient(#333,#999);
      color: #fff;
    }
    button.equal {
      background: linear-gradient(#333,#999);
      grid-column: span 1;
      color: #fff;
    }
  </style>
</head>
<body>
  <div class="calculator">
    <div class="screen" id="screen">0</div>
    <div class="buttons">
      <button type="button" class="operator">C</button>
      <button type="button" class="operator">±</button>
      <button type="button" class="operator">%</button>
      <button type="button" class="operator">÷</button>
      <button type="button">7</button>
      <button type="button">8</button>
      <button type="button">9</button>
      <button type="button" class="operator">x</button>
      <button type="button">4</button>
      <button type="button">5</button>
      <button type="button">6</button>
      <button type="button" class="operator">-</button>
      <button type="button">1</button>
      <button type="button">2</button>
      <button type="button">3</button>
      <button type="button" class="operator">+</button>
      <button type="button" class="special">π</button>
      <button type="button">0</button>
      <button type="button">.</button>
      <button type="button" class="equal">=</button>
      </div>
  </div>
  <script>
  document.addEventListener('DOMContentLoaded', function() {
    const screen = document.getElementById('screen');
    const buttons = document.querySelectorAll('.buttons button');
    let calculation = '';
    let currentInput = '';
    let lastOperator = '';
    function updateScreen(value) {
      screen.textContent = value;
    }
    buttons.forEach(button => {
      button.addEventListener('click', () => {
        const buttonText = button.textContent;
        if (buttonText === 'C') {
          calculation = '';
          currentInput = '';
          lastOperator = '';
          updateScreen('0');
        } else if (buttonText === '±') {
          if (currentInput) {
            currentInput = (parseFloat(currentInput) * -1).toString();
            updateScreen(currentInput);
          }
        } else if (buttonText === '%') {
          if (currentInput) {
            currentInput = (parseFloat(currentInput) / 100).toString();
            updateScreen(currentInput);
          }
        } else if (buttonText === 'π') {
          currentInput = Math.PI.toString();
          updateScreen(currentInput);
        } else if (buttonText === '=') {
          if (currentInput && lastOperator) {
            calculation += currentInput;
            try {
              calculation = eval(calculation).toString();
              updateScreen(calculation);
              currentInput = calculation;
              calculation = '';
              lastOperator = '';
            } catch (e) {
              updateScreen('Error');
              calculation = '';
              currentInput = '';
              lastOperator = '';
            }
          }
        } else if (['÷', 'x', '-', '+'].includes(buttonText)) {
          if (currentInput) {
            calculation += currentInput;
            calculation += buttonText === '÷' ? '/' : buttonText === 'x' ? '*' : buttonText;
            lastOperator = buttonText;
            currentInput = '';
            updateScreen(buttonText);
          }
        } else {
          currentInput += buttonText;
          updateScreen(currentInput);
        }
      });
    });
  });
  </script>
</body>
</html>

Japanese Zen Garden Scientific Calculator - MeggiTools