居中一个具有100vh高度的背景图上的div
我正在学习一门课程，其中顶部有一个固定位置的导航栏。背景设置为100vh的高度，带有文本内容的div位于背景的中心。使用 Flexbox 它几乎居中，但为了真正使其到达背景中心，该 div 的高度必须设置为 100% 的高度。我对 Flexbox 和视口高度有所了解，但是我对为什么需要将 div 的高度设置为 100% 才能真正使潜水居中感到困惑。我想你可以在这里放置任何图像作为背景来复制我所要求的内容。希望我在这里说得通。
* {
box-sizing: border-box;
margin: 0;
padding: 0;
}
body {
font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
background: #fff;
color: #333;
line-height: 1.5;
}
ul {
list-style: none;
}
a {
color: #333;
text-decoration: none;
}
h1,
h2 {
font-weight: 300px;
line-height: 1.5:
}
p {
margin: 10px 0;
}
img {
width: 100%;
/*makes image width of the container */
}
/* navbar */
.navbar {
display: flex;
align-items: center;
justify-content: space-between;
background-color: #333;
color: #fff;
width: 100%;
height: 70px;
/* apparently a common height for navbar */
position: fixed;
top: 0px;
padding: 0 30px;
}
.navbar a {
color: #fff;
padding: 10px 20px;
margin: 0 5px;
}
.navbar a:hover {
border-bottom: 1px solid #28a745;
}
.navbar ul {
display: flex;
}
/* Header */
.hero {
background: url("/img/home/showcase.jpg") no-repeat center center/cover;
height: 100vh;
position: relative;
color: #fff;
}
.hero .content {
display: flex;
flex-direction: column;
align-items: center;
justify-content: center;
text-align: center;
height: 100%;
}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Welcome to EdgeLedger</title>
<link rel="stylesheet" href="/css/utilities.css">
<!-- style.css is last in case utilities.css needs to be overwritten -->
<link rel="stylesheet" href="/css/style.css">
<script src="https://kit.fontawesome.com/6eab1538de.js" crossorigin="anonymous"></script>
</head>
<body id="home">
<header class="hero">
<div id="navbar" class="navbar">
<h1 class="logo">
<span class="text-primary"><i class="fas fa-book-open"></i>Edge</span>Ledger
</h1>
<nav>
<ul>
<li><a href="#home">Home</a></li>
<li><a href="#about">About</a></li>
<li><a href="#cases">Cases</a></li>
<li><a href="#blog">Blog</a></li>
<li><a href="#contact">Contact</a></li>
</ul>
</nav>
</div>
<div class="content">
<h1>The sky is the limit</h1>
<p>We provide world class financial assistance</p>
<a href="#about" class="btn">Read More</a>
</div>
</header>
</body>
</html>
