SF javascriptx input
: 
PS: I just found a code on the Internet, but I tried to reply in the input box: Gao Yang can never exist as a whole. If you delete it, you still want to delete it word by word
<!DOCTYPE html>
<html>
<head>
<title></title>
<style type="text/css">
.input{
width:200px;
height:24px;
line-height:24px;
font-size:14px;
padding:5px 8px;
border:1px solid -sharpddd;
}
.input:empty::before {
content: attr(placeholder);
}
</style>
</head>
<body>
<div class="input" contenteditable placeholder="">
<span>:</span>
</div>
</body>
</html>