When quoting jquery-confirm in the past few days, after introducing it, I found that the pop-up box was as wide as the page. Later, I found that the bundled.css in the demo was rarely introduced. After opening it, I found that bundled.css is normalize.css. This css can be viewed if you are interested. one time
Below is the reference in my code
<script src="../js/jquery.js"></script>
<script src="../js/jquery-confirm.js"></script>
<link rel="stylesheet" href="../css/jquery-confirm.css">
<link rel="stylesheet" href="../css/bundled.css">
jquery-confirm download address: http://craftpip.github.io/jquery-confirm/