以下是代码段中的html和css：
* {
margin: 0;
padding: 0;
}
html, body {
height: 100%;
width: 100%;
}
header {
height: 100px;
background-color: #35424a;
border-bottom: #e8491d 5px solid;
}
h1 {
float: left;
margin-top: auto;
margin-bottom: auto;
color: white;
}
.acme {
color: #e8491d;
}
nav {
float: right;
margin-top: auto;
margin-bottom: auto;
}
li {
display: inline;
font-size: 150%;
padding: 0px 20px;
}<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<link rel="stylesheet" href="style.css">
<title>Document</title>
</head>
<body>
<header>
<h1><span class="acme">Acme </span>Web Design</h1>
<nav>
<ul>
<li>HOME</li>
<li>ABOUT</li>
<li>SERVICES</li>
</ul>
</nav>
</header>
</body>
</html>问题是h1和导航我将顶部和底部边距设置为自动并且标题高度为100px（边框为105px），即使页边距自动仍然不起作用我试图添加
display: block;
但仍然没有发生任何事情
您只需将header CSS更新为：
header {
display: flex;
justify-content: space-between;
width: 100%;
align-items: center;
height: 100px;
background-color: #35424a;
border-bottom: #e8491d 5px solid;
}
这解决了问题
- >请将以下代码附加到附件中。
* {
margin: 0;
padding: 0;
}
html, body {
height: 100%;
width: 100%;
}
header {
height: 100px;
background-color: #35424a;
border-bottom: #e8491d 5px solid;
}
h1 {
float: left;
margin-top: auto;
margin-bottom: auto;
color: white;
}
.acme {
color: #e8491d;
}
nav {
float: right;
margin-top: auto;
margin-bottom: auto;
}
li {
display: inline;
font-size: 150%;
padding: 0px 20px;
}
.display-table {
display: table;
height: 100%;
width: 100%;
}
.vertical-content {
display: table-cell;
vertical-align: middle;
height: 100%;
width: 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">
<!-- The above 3 meta tags *must* come first in the head; any other head content must come *after* these tags -->
<title>Stack</title>
<link href="css/style.css" rel="stylesheet">
</head>
<body>
<header>
<div class="display-table">
<div class="vertical-content">
<h1><span class="acme">Acme </span>Web Design</h1>
<nav>
<ul>
<li>HOME</li>
<li>ABOUT</li>
<li>SERVICES</li>
</ul>
</nav>
</div>
</div>
</header>
</body>
</html>HTML不适用于margin-top或margin-bottom，你需要创建一个flex展示，请检查：https://css-tricks.com/snippets/css/a-guide-to-flexbox/
根据你的需要，你需要这样做：
display: flex;
align-items: center;
如果您需要flex的其他内容，请检查链接