<!doctype html> <style> body {background-image:url(“ ”); } .avatar {margin-top:auto; 底边距:自动; 保证金:8%; } .margin {margin-top:auto; 底边距:自动; 保证金:8%; } img {border-radius:50%; } </ style> <title> Jam Music </ title> <!-- Optional JavaScript --> <!-- jQuery first, then Popper.js, then Bootstrap JS --> <script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" integrity="sha384-DfXdz2htPH0lsSSs5nCTp