Use the marginBottom property in JavaScript, to set the bottom margin.
Example
You can try to run the following code to set the bottom margin of an element with JavaScript −
<!DOCTYPE html> <html> <body> <p id="myID">This is demo text.</p> <button type="button" onclick="display()">Set bottom margin</button> <script> function display() { document.getElementById("myID").style.marginBottom = "95px"; } </script> </body> </html>