test

✨ ANUWAT PRASIT

<!DOCTYPE html>
<html>
  
<body>
    <center>
        <h1 style="color: green">GeeksForGeeks</h1>
        <button type="button" 
            onclick="changeSizeByBtn(15)" name="btn1">
            -A
        </button>
          
        <button type="button" 
            onclick="changeSizeByBtn(20)" name="btn2">
            A
        </button>
  
        <button type="button" onclick="changeSizeByBtn(25)"
            name="btn3">
            A+
        </button>
        <br /><br />
  
        <div style="padding: 20px; margin: 50px;
            font-size: 20px; border: 5px solid green;" 
            id="container" class="container">
              
            <p>
                A Computer Science portal for geeks. 
                It contains well written, well thought 
                and well explained computer scienc and 
                programming articles quizzes and practice/ 
                competitive programming/company interview 
                questions.
            </p>
        </div>
  
        <input type="range" min="10" max="30" id="slider"
            onchange="changeSizeBySlider()" value="20" />
    </center>
  
    <script>
        var cont = document.getElementById("container");
  
        function changeSizeByBtn(size) {
  
            cont.style.fontSize = size;
        }
  
        function changeSizeBySlider() {
            var slider = document.getElementById("slider");
            cont.style.fontSize = slider.value;
        }
    </script>
</body>
  
</html>