React Js Scrollable List with Dynamic Font Size

<!DOCTYPE html>
<html>

<body>
  <div id="app"></div>
  <script type="text/babel">
    const { useState, useEffect } = React;
    function App() {
      const items = ['Item 1', 'Item 2', 'Item 3', 'Item 4', 'Item 5','Item 6','Item 7','Item 8'];

const [fontSizeMap, setFontSizeMap] = useState({});

const handleMouseEnter = (index) => {
        setFontSizeMap((prevSizeMap) => ({
          ...prevSizeMap,
          [index]: calculateFontSize(index),
        }));
      };

const handleMouseLeave = (index) => {
        setFontSizeMap((prevSizeMap) => ({
          ...prevSizeMap,
          [index]: undefined,
        }));
      };

const calculateFontSize = (index) => {
        // You can implement your own logic here to calculate font-size dynamically
        return 12 + index * 2;
      };

return (
        <div className="container">
          <h1>Dynamic Font-Size Scrollable List</h1>
          <div className="scrollable-list">
            {items.map((item, index) => (
              <div
                key={index}
                className="list-item"
                style={{ fontSize: fontSizeMap[index] }}
                onMouseEnter={() => handleMouseEnter(index)}
                onMouseLeave={() => handleMouseLeave(index)}
              >
                {item}
              </div>
            ))}
          </div>
        </div>
      );
    }
    ReactDOM.render(<App />, document.getElementById('app'));
  </script>
  <style>
    .container {
      max-width: 500px;
      margin: 0 auto;
      padding: 20px;
      border-radius: 8px;
      box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
      text-align: center;

}

.scrollable-list {
      width: 300px;
      height: 400px;
      overflow: auto;
      border: 1px solid #ccc;
    }

.list-item {
      padding: 10px;
      transition: font-size 0.2s ease-in-out;
      cursor: pointer;
    }

.list-item:hover {
      background-color: #f0f0f0;
    }
  </style>
</body>

</html>

 
<!DOCTYPE html>
<html>
​
<head>
  <meta charset="UTF-8" />
  <script src="https://unpkg.com/react@17.0.2/umd/react.development.js"></script>
  <script src="https://unpkg.com/react-dom@17.0.2/umd/react-dom.development.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/babel-standalone/6.26.0/babel.min.js"></script>
</head>
​
<body>
  <div id="app"></div>
  <script type="text/babel">
    const { useState, useEffect } = React;
    function App() {
      const items = ['Item 1', 'Item 2', 'Item 3', 'Item 4', 'Item 5','Item 6','Item 7','Item 8'];
​
      const [fontSizeMap, setFontSizeMap] = useState({});
​
      const handleMouseEnter = (index) => {
        setFontSizeMap((prevSizeMap) => ({
          ...prevSizeMap,
          [index]: calculateFontSize(index),
        }));
      };
​
      const handleMouseLeave = (index) => {
        setFontSizeMap((prevSizeMap) => ({
          ...prevSizeMap,
          [index]: undefined,
        }));
      };
​
      const calculateFontSize = (index) => {
        // You can implement your own logic here to calculate font-size dynamically
        return 12 + index * 2;
      };
​
      return (
        <div className="container">
          <h1>Dynamic Font-Size Scrollable List</h1>
          <div className="scrollable-list">
            {items.map((item, index) => (
              <div
                key={index}
                className="list-item"
                style={{ fontSize: fontSizeMap[index] }}
                onMouseEnter={() => handleMouseEnter(index)}
                onMouseLeave={() => handleMouseLeave(index)}
              >
                {item}
              </div>
            ))}
          </div>
        </div>
      );
    }
    ReactDOM.render(<App />, document.getElementById('app'));
  </script>
  <style>
    .container {
      max-width: 500px;
      margin: 0 auto;
      padding: 20px;
      border-radius: 8px;
      box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
      text-align: center;
​
    }
​
    .scrollable-list {
      width: 300px;
      height: 400px;
      overflow: auto;
      border: 1px solid #ccc;
    }
​
    .list-item {
      padding: 10px;
      transition: font-size 0.2s ease-in-out;
      cursor: pointer;
    }
​
    .list-item:hover {
      background-color: #f0f0f0;
    }
  </style>
</body>
​
</html>