<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style type="text/css">
#container{
display: flex;
width: 500px;
border: 1px solid red;
}
#box1{
background-color: mediumspringgreen;
width: 100px;
flex-grow: 0;
}
#box2{
background-color: greenyellow;
flex-grow: 1;
}
</style>
</head>
<body>
<div id="container">
<div id="box1">
定宽
</div>
<div id="box2">
填满
</div>
</div>
</body>
</html>
