我正在尝试制作一个响应式导航栏，以便当用于访问网站的设备太小而无法容纳整个导航栏时，它会折叠成一个下拉菜单。奇怪的是，我使用的媒体查询似乎对网站没有任何作用。在我的 HTML 文件的头部，我有这个:<meta name="viewport" content="width=device-width, initial-scale=0.8" >
这是CSS:
@media screen and (max-width: 800px) {
ul.topnav li:not(: first-child) {
display: none;
}
ul.topnav li.icon {
float: right;
display: inline-block;
}
ul.topnav.responsive {
position: relative;
}
ul.topnav.responsive li.icon {
position: absolute;
right: 0;
top: 0;
}
ul.topnav.responsive li {
float: none;
display: inline;
}
ul.topnav.responsive li a {
display: block;
text-align: left;
}
}
var main = function () {
function openNav() {
var x = document.getElementById("topnav");
if (x.className === "topnav") {
x.className += " responsive";
} else {
x.className = "topnav";
}
}
}
$(document).ready(main);.jumbotron p {
font-weight: 400;
font-family: 'roboto', sans-serif;
}
.topnav {
font-family: 'Montserrat', sans-serif;
font-size: 16px;
background-color: transparent;
color: black;
transition: all 0.25s ease;
position: fixed;
top: 0;
width: 100%;
padding: 20px;
}
ul.topnav {
list-style-type: none;
margin: 0;
overflow: hidden;
display: flex;
align-items: center;
}
ul.topnav li {
float: left;
}
ul.topnav li.icon {
display: none;
}
.topnav a {
margin-left: 20px;
text-decoration: none;
color: black;
}
.topnav a:hover {
margin-left: 20px;
text-decoration: none;
color: #FACD00;
}
@media screen and (max-width: 800px) {
ul.topnav li:(not: first-child) {
display: none;
}
ul.topnav li.icon {
float: right;
display: inline-block;
}
ul.topnav.responsive {
position: relative;
}
ul.topnav.responsive li.icon {
position: absolute;
right: 0;
top: 0;
}
ul.topnav.responsive li {
float: none;
display: inline;
}
ul.topnav.responsive li a {
display: block;
text-align: left;
}
}<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.2.3/jquery.min.js"></script>
<!DOCTYPE html>
<body>
<!--navbar-->
<ul class="topnav">
<li><a href="#">Home</a></li>
<li><a href="#">Events</a></li>
<li><a href="#">About</a></li>
<li><a href="#">Volunteer</a></li>
<li><a href="#">Contact</a></li>
<li class="icon">
<a href="javascript:void(0);" onclick="openNav()">☰</a>
</ul>
</body>最佳答案
只需将媒体查询放在 css 文件的底部即可。 CSS 规则按特异性应用，当具有相同特异性(这是你的情况)时按选择器出现的顺序应用。
还纠正了 Artem Gorlachev 指出的语法错误。
.jumbotron p {
font-weight: 400;
font-family: 'roboto', sans-serif;
}
.topnav {
font-family: 'Montserrat', sans-serif;
font-size: 16px;
background-color: transparent;
color: black;
transition: all 0.25s ease;
position: fixed;
top: 0;
width: 100%;
padding: 20px;
}
ul.topnav {
list-style-type: none;
margin: 0;
overflow: hidden;
display: flex;
align-items: center;
}
ul.topnav li {
float: left;
}
ul.topnav li.icon {
display: none;
}
.topnav a {
margin-left: 20px;
text-decoration: none;
color: black;
}
.topnav a:hover {
margin-left: 20px;
text-decoration: none;
color: #FACD00;
}
@media screen and (max-width: 800px) {
ul.topnav li:not(:first-child) {
display: none;
}
ul.topnav li.icon {
float: right;
display: inline-block;
}
ul.topnav.responsive {
position: relative;
}
ul.topnav.responsive li.icon {
position: absolute;
right: 0;
top: 0;
}
ul.topnav.responsive li {
float: none;
display: inline;
}
ul.topnav.responsive li a {
display: block;
text-align: left;
}
}
关于html - 媒体查询和视口(viewport)不工作，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/39194763/