index.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
  <title>Calculator</title>
  <link href="https://fonts.googleapis.com/css2?family=Share+Tech+Mono&family=Bebas+Neue&display=swap" rel="stylesheet"/>
  <link rel="stylesheet" href="style.css"/>
</head>
<body>
  <div class="calculator">
    <div class="brand">CALCΛ</div>
    <div class="display">
      <div class="expression" id="expression"></div>
      <div class="result" id="result">0</div>
    </div>
    <div class="buttons">
      <button class="btn span-two fn" data-action="clear">AC</button>
      <button class="btn fn" data-action="sign">+/−</button>
      <button class="btn op" data-value="/">÷</button>

      <button class="btn num" data-value="7">7</button>
      <button class="btn num" data-value="8">8</button>
      <button class="btn num" data-value="9">9</button>
      <button class="btn op" data-value="*">×</button>

      <button class="btn num" data-value="4">4</button>
      <button class="btn num" data-value="5">5</button>
      <button class="btn num" data-value="6">6</button>
      <button class="btn op" data-value="-">−</button>

      <button class="btn num" data-value="1">1</button>
      <button class="btn num" data-value="2">2</button>
      <button class="btn num" data-value="3">3</button>
      <button class="btn op" data-value="+">+</button>

      <button class="btn span-two num" data-value="0">0</button>
      <button class="btn num" data-value=".">.</button>
      <button class="btn eq" data-action="equals">=</button>
    </div>
  </div>
  <script src="script.js"></script>
</body>
</html>