如何使用JavaScript更改警报框的样式？
您将无法在JavaScript中更改标准警报框的样式。要更改样式，请使用以下自定义警报框。我们正在使用JavaScript库，jQuery实现此目的。
示例
<!DOCTYPE html>
<html>
<head>
<script src="https://cdn.staticfile.org/jquery/3.2.1/jquery.min.js">
</script>
<script>
function functionAlert(msg, myYes) {
var confirmBox = $("#confirm");
confirmBox.find(".message").text(msg);
confirmBox.find(".yes").unbind().click(function() {
confirmBox.hide();
});
confirmBox.find(".yes").click(myYes);
confirmBox.show();
}
</script>
<style>
#confirm {
display: none;
background-color: #514E61;
color: #FFFFFF;
border: 1px solid #aaa;
position: fixed;
width: 250px;
left: 50%;
margin-left: -100px;
padding: 6px 8px 8px;
box-sizing: border-box;
text-align: center;
}
#confirm button {
background-color: #48E5DA;
display: inline-block;
border-radius: 5px;
border: 1px solid #aaa;
padding: 5px;
text-align: center;
width: 80px;
cursor: pointer;
}
#confirm .message {
text-align: left;
}
</style>
</head>
<body>
<div id="confirm">
<div class="message">This is a warning message.</div>
<button class="yes">OK</button>
</div>
<input type="button" value="Click Me" onclick="functionAlert();" />
</body>
</html>