我有一个非常简单的页面（现在就练习）。我有一个红色边框和蓝色背景的div。 div内部是一个调用外部js文件的标签。 js正在工作，但是div的边界消失了。
这是代码。
var myArray = [
"Item one",
"Item two",
"Item three"
];
var randomItemOne = myArray[Math.floor(Math.random() * myArray.length)];
document.body.innerHTML = randomItemOne;.box1 {
border: solid 2px red;
width: 200px;
height: 150px;
background-color: skyblue;
}HTML
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Random Text Selector</title>
<meta name="description" content="The HTML5 Herald">
<link rel="stylesheet" href="rt_style.css">
</head>
<body>
<div class="box1">
<script src="js/random.js"></script>
</div>
</body>
</html>var myArray = [
"Item one",
"Item two",
"Item three"
];
var randomItemOne = myArray[Math.floor(Math.random() * myArray.length)];
document.getElementsByClassName("box1")[0].innerText = randomItemOne;.box1 {
border: solid 2px red;
width: 200px;
height: 150px;
background-color: skyblue;
}HTML
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Random Text Selector</title>
<meta name="description" content="The HTML5 Herald">
<link rel="stylesheet" href="rt_style.css">
</head>
<body>
<div class="box1">
<script src="js/random.js"></script>
</div>
</body>
</html>我认为这是你想要实现的目标。如果我错了，请纠正我