我已经决定先将我的网站设为移动设备，因此我创建了一个标题为“块级元素”的标题。这意味着要在列中显示它做得非常好。但是，无论我做什么，即使使用flexbox，我也无法将显示变成水平导航栏。它意味着转向css文件底部的960媒体查询导航。
<html lang="en" dir="ltr">
<head>
<meta charset="utf-8">
<title></title>
<link rel="stylesheet" href="styles.css">
<link href="https://fonts.googleapis.com/css?family=Roboto:300i" rel="stylesheet">
</head>
<body>
<header>
<nav>
<li><a href = "#"> Home</a></li>
<li><a href = "#"> Heading1</a></li>
<li><a href = "#"> Heading2</a></li>
<li><a href = "#"> Heading3</a></li>
</nav>
</header>
<div class="container">
<div class="side1">
<h2>Column 1</h2>
<p>
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
</p>
</div>
<div class="main-content">
<h2>Main-content</h2>
<p>
"But I must explain to you how all this mistaken idea of denouncing pleasure and praising pain was born and I will give you a complete account of the system, and expound the actual teachings of the great explorer of the truth, the master-builder of human happiness. No one rejects, dislikes, or avoids pleasure itself, because it is pleasure, but because those who do not know how to pursue pleasure rationally encounter consequences that are extremely painful. Nor again is there anyone who loves or pursues or desires to obtain pain of itself, because it is pain, but because occasionally circumstances occur in which toil and pain can procure him some great pleasure. To take a trivial example, which of us ever undertakes laborious physical exercise, except to obtain some advantage from it? But who has any right to find fault with a man who chooses to enjoy a pleasure that has no annoying consequences, or one who avoids a pain that produces no resultant pleasure?"
</p>
</div>
<div class="side2">
<h2>Column 2</h2>
<p>
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
</p>
</div>
</div>
</body>
</html>
这是我的CSS
header {
-webkit-box-shadow: -1px 2px 17px 0px rgba(0,0,0,0.75);
-moz-box-shadow: -1px 2px 17px 0px rgba(0,0,0,0.75);
box-shadow: -1px 2px 17px 0px rgba(0,0,0,0.75);
display:inline-block;
width: 100%;
border-radius: 5px;
background-color: white;
border-color: black;
height: 40%;
margin-bottom: 3%;
padding: 20px;
}
nav {
display: block;
}
nav li {
font-weight: 700;
list-style-type: none;
text-align: center;
font-size: 25px;
font-weight: bold;
font-family: Roboto, sans-serif;
}
li {
border-top: grey solid 1px;
}
nav a {
text-decoration: none;
color: grey;
display:inline-block;
line-height: 45px;
}
li:nth-child(1){
border-top: none;
padding-bottom:10px;
margin:0px;
}
li:nth-child(2){
padding-top:10px;
margin:0px;
}
li:nth-child(3){
margin:0px;
padding-top:10px;
}
li:nth-child(4){
margin:0px;
padding-top:10px;
}
.container {
display: flex;
flex-direction: column;
flex-wrap: nowrap;
justify-content: space-between;
font-family: Roboto,sans-serif;
line-height: 1.6;
}
.side1 {
-webkit-box-shadow: -1px 2px 17px 0px rgba(0,0,0,0.75);
-moz-box-shadow: -1px 2px 17px 0px rgba(0,0,0,0.75);
box-shadow: -1px 2px 17px 0px rgba(0,0,0,0.75);
width:100%;
background: white;
border-color: black;
text-align: center;
margin-bottom: 10px;
}
.main-content {
-webkit-box-shadow: -1px 2px 17px 0px rgba(0,0,0,0.75);
-moz-box-shadow: -1px 2px 17px 0px rgba(0,0,0,0.75);
box-shadow: -1px 2px 17px 0px rgba(0,0,0,0.75);
width:100%;
background: white;
border-color: black;
text-align: center;
margin-bottom: 10px;
}
.side2 {
-webkit-box-shadow: -1px 2px 17px 0px rgba(0,0,0,0.75);
-moz-box-shadow: -1px 2px 17px 0px rgba(0,0,0,0.75);
box-shadow: -1px 2px 17px 0px rgba(0,0,0,0.75);
width:100%;
background: white;
border-color: black;
text-align: center;
margin-bottom: 10px;
}
@media screen and (min-width : 726px) {
@media screen and (min-width : 900px) {
.header {
display:flex;
}
.nav {
display: flex;
flex-direction: row;
}
.container {
display:flex;
flex-direction: row;
align-items: center;
justify-content: space-around;
flex-wrap: wrap;
}
.main-content {
border-left: lightgrey 1px solid;
border-right: lightgrey 1px solid;
width: 33.3%;
}
.side1 {
width: 30%;
}
.side2 {
width: 30%;
}
}
答案 0 :(得分：0)
您应该将.header更改为header，将.nav更改为nav，以便为媒体查询中的标题和导航标记定义类。点.不应该使用，因为您没有定位类，而是标记。
@media screen and (min-width : 900px) {
header {
display:flex;
}
nav {
display: flex;
flex-direction: row;
}
.container {
display:flex;
flex-direction: row;
align-items: center;
justify-content: space-around;
flex-wrap: wrap;
}
.main-content {
border-left: lightgrey 1px solid;
border-right: lightgrey 1px solid;
width: 33.3%;
}
.side1 {
width: 30%;
}
.side2 {
width: 30%;
}
}