我最近开始使用 html 为我的项目创建一个网站。我计划制作这个包含介绍页面的网站，该页面有一个按钮，可显示更多内容。 这是我当前的html代码：
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Chem project</title>
<link rel="stylesheet" href="style.css">
<link href="https://fonts.googleapis.com/css2?family=Montserrat:wght@400;700&display=swap" rel="stylesheet">
</head>
<body>
<div id="box">
<h1 id="title">Brief Introduction</h1>
<hr id="underline">
<div id="content">
<p>content</p>
</div>
</div>
<br>
<div id="button-container" class="button">
<a id="know-more-button" href="secondpage.html">Know More</a>
</div>
</body>
</html>
对应的css代码为：
body {
font-family: Arial, sans-serif;
margin: 0;
padding: 0;
background-color: #24576c;
display: flex;
justify-content: center;
align-items: center;
height: 100vh;
}
#box {
width: 80%;
background-color: #D5C6EE;
border: 1px solid #ccc;
border-radius: 10px;
padding: 20px;
box-shadow: 0px 4px 8px rgba(0, 0, 0, 0.1);
display: flex;
flex-direction: column;
justify-content: space-between;
height: auto;
}
#title {
text-align: center;
margin-bottom: 10px;
font-weight: bold;
}
#underline {
border: none;
height: 2px;
background-color: #131E62;
width: 100%;
margin-bottom: 20px;
}
#content {
font-size: 20px;
text-align: justify;
line-height: 1.6;
flex-grow: 1;
}
.button {
display: flex;
justify-content: center;
margin-top: 20px;
}
#know-more-button {
text-decoration: none;
background-color: #AABFEF;
color: white;
padding: 10px 20px;
border: none;
border-radius: 5px;
font-size: 16px;
cursor: pointer;
}
#know-more-button:hover {
background-color: #0056b3;
}
body {
background-image: url("https://c.wallhere.com/photos/c6/5c/chemistry_science_laboratories-1697571.jpg!d");
background-size: cover;
background-repeat: no-repeat;
background-position: center;
height: 100vh;
margin: 0;
}
一切都很好，除了我期望位于盒子底部的“了解更多按钮”。 （如下图）
我想请求您的帮助，以使按钮出现在正确的位置。 :)
按钮的
div它应该看起来像这样：
<div id="box">
<h1 id="title">Brief Introduction</h1>
<hr id="underline">
<div id="content">
<p>content</p>
</div>
<br>
<div id="button-container" class="button">
<a id="know-more-button" href="secondpage.html">Know More</a>
</div>
</div>