java-programs/calculator.html at master · KumarRitik5/java-programs · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Modern Calculator</title>
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <style>
    body {
      background: linear-gradient(to right, #e0eafc, #cfdef3);
      font-family: 'Segoe UI', sans-serif;
      display: flex;
      justify-content: center;
      align-items: center;
      height: 100vh;
      margin: 0;
    }

    .calculator {
      background: #ffffff;
      padding: 25px;
      border-radius: 25px;
      box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
      width: 340px;
    }

    .display {
      width: 100%;
      height: 60px;
      font-size: 26px;
      text-align: right;
      margin-bottom: 20px;
      padding: 10px 15px;
      border: none;
      border-radius: 12px;
      background: #f9f9f9;
      box-shadow: inset 0 2px 5px rgba(0,0,0,0.05);
    }

    .buttons {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 15px;
    }

    button {
      padding: 18px;
      font-size: 18px;
      font-weight: bold;
      border: none;
      border-radius: 15px;
      cursor: pointer;
      background: #ececec;
      box-shadow: 0 6px #bebebe;
      transition: 0.2s;
    }

    button:active {
      transform: translateY(4px);
      box-shadow: 0 2px #9e9e9e;
    }

    .operator {
      background: #ffd166;
      box-shadow: 0 6px #e6b952;
    }

    .equal {
      background: #06d6a0;
      color: white;
      box-shadow: 0 6px #05b88b;
    }

    .clear {
      background: #ef476f;
      color: white;
      box-shadow: 0 6px #d13b61;
    }
  </style>
</head>
<body>

  <div class="calculator">
    <input type="text" id="display" class="display" readonly>

    <div class="buttons">
      <button class="clear" onclick="clearDisplay()">C</button>
      <button onclick="appendValue('(')">(</button>
      <button onclick="appendValue(')')">)</button>
      <button class="operator" onclick="appendOperator('/')">÷</button>

      <button onclick="appendValue('7')">7</button>
      <button onclick="appendValue('8')">8</button>
      <button onclick="appendValue('9')">9</button>
      <button class="operator" onclick="appendOperator('*')">×</button>

      <button onclick="appendValue('4')">4</button>
      <button onclick="appendValue('5')">5</button>
      <button onclick="appendValue('6')">6</button>
      <button class="operator" onclick="appendOperator('-')">−</button>

      <button onclick="appendValue('1')">1</button>
      <button onclick="appendValue('2')">2</button>
      <button onclick="appendValue('3')">3</button>
      <button class="operator" onclick="appendOperator('+')">+</button>

      <button onclick="appendValue('0')">0</button>
      <button onclick="appendValue('.')">.</button>
      <button class="equal" onclick="calculate()">=</button>
    </div>
  </div>

  <script>
    const display = document.getElementById('display');
    const operators = ['+', '-', '*', '/'];

    function appendValue(val) {
      display.value += val;
    }

    function appendOperator(op) {
      const lastChar = display.value.slice(-1);
      if (operators.includes(lastChar)) {
        // Replace the last operator
        display.value = display.value.slice(0, -1) + op;
      } else if (display.value !== '') {
        display.value += op;
      }
    }

    function clearDisplay() {
      display.value = '';
    }

    function calculate() {
      try {
        const result = eval(display.value);
        display.value = result;
      } catch {
        display.value = 'Error';
      }
    }

    // Keyboard input support
    document.addEventListener('keydown', (e) => {
      const key = e.key;
      if (!isNaN(key) || ['(', ')', '.'].includes(key)) {
        appendValue(key);
      } else if (operators.includes(key)) {
        appendOperator(key);
      } else if (key === 'Enter') {
        e.preventDefault();
        calculate();
      } else if (key === 'Backspace') {
        display.value = display.value.slice(0, -1);
      } else if (key === 'Escape') {
        clearDisplay();
      }
    });
  </script>

</body>
</html>