如果查看代码，缩小页面时，菜单会快速显示，然后向下滑动。当页面缩小时，我希望它不会显示出来。我无法理解为什么会这样。
我认为它可能是#nav而不是input[type="checkbox"]:checked + #nav上的过渡，但我需要在#nav上有动画。我有一个单独的文件，我只用于移动导航，它工作得很好。一旦我开始处理媒体查询，事情便会向南发展。
这里的小提琴： https://jsfiddle.net/reizer/fwzsxrnt/
* {margin:0;padding:0;border:0;list-style:none;font-size:100%;font:inherit;vertical-align:baseline;}
/*RESET*/
body {font: 1em Arial, Helvetica, sans-serif;}
#wrapper {
max-width: 960px;
margin: auto;
}
#nav {
display: block;
max-height: 0em;
overflow: hidden;
transition: max-height 0.5s ease;
-webkit-transition: max-height 0.5s ease;
-moz-transition: max-height 0.5s ease;
-o-transition: max-height 0.5s ease;
}
input[type="checkbox"] {
position: absolute;
margin-top: -100em;
}
input[type="checkbox"]:checked + #nav{
max-height: 20em;
}
label {
background: #9c0;
cursor: pointer;
display: block;
overflow: auto;
padding-left: 1em;
background-color: #9C0;
background: -moz-linear-gradient(top, #99cc00 0%, #85b100 100%);
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#99cc00), color-stop(100%,#85b100));
background: -webkit-linear-gradient(top, #99cc00 0%,#85b100 100%);
background: -o-linear-gradient(top, #99cc00 0%,#85b100 100%);
background: -ms-linear-gradient(top, #99cc00 0%,#85b100 100%);
background: linear-gradient(to bottom, #99cc00 0%,#85b100 100%);
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#99cc00', endColorstr='#85b100',GradientType=0 );
-webkit-touch-callout: none;
-webkit-user-select: none;
-khtml-user-select: none;
-moz-user-select: none;
-ms-user-select: none;
user-select: none;
color: #FFF;
font-size: 1.6em;
line-height: 2.6em;
}
label:after {
content: "\f039";
float: right;
background-color: #669900;
padding: 0.2em 0.3em 0.1em;
margin: 0.5em;
font: 1.2em FontAwesome;
border-radius: 0.3em;
-webkit-box-shadow: inset 0em 0.1em 0.2em 0em rgba(0,0,0,0.3);
-moz-box-shadow: inset 0em 0.1em 0.2em 0em rgba(0,0,0,0.3);
box-shadow: inset 0em 0.1em 0.2em 0em rgba(0,0,0,0.3);
}
#nav ul li a {
background: #690;
border: solid #90c12f;
border-width: 1px 0 0;
text-decoration: none;
padding: 1em;
display: block;
color: #FFF;
}
#nav ul li a:hover, #nav ul li a:active {
background: #abd728;
}
@media screen and (min-width: 479px) {
.d----onttouchshituntilthispoin----t {
}
label {
display:none;
}
#nav {
display: table;
width: 100%;
max-height: 20em;
overflow: auto;
}
#nav ul {
display: table-row;
}
#nav ul li {
display: table-cell;
}
#nav ul li a {
color: #000;
position: relative;
text-align: center;
text-indent: 20px;
border: solid #000;
border-width: 0 1px 0 0;
line-height: 3.4em;
padding: 0px 20px 0px 0px;
transition: all 0.5s ease;
-webkit-transition: all 0.5s ease;
-o-transition: all 0.5s ease;
-moz-transition: all 0.5s ease;
} #nav ul li:last-child a{border:none}
#nav ul li a:hover {
position: relative;
text-indent: 0px;
padding-right: 40px;
}
#nav ul li a:before {
font-family: FontAwesome;
content: "\f078";
position: absolute;
right: 1em;
margin-top: -0.85em;
visibility: hidden;
opacity: 0;
-webkit-transition: all 0.5s ease;
transition: all 0.5s ease;
-o-transition: all 0.5s ease;
-moz-transition: all 0.5s ease;
}
#nav ul li a:hover:before {
margin-top: 0em;
visibility: visible;
opacity: 1;
}
#nav ul li a ul li {
position: absolute;
background: #FF0;
display: block;
width: 100%;
height: 0em;
visibility: hidden;
opacity: 0;
border-radius: 0px 0px 5px 5px;
-moz-border-radius: 0px 0px 5px 5px;
-webkit-border-radius: 0px 0px 5px 5px;
-webkit-transition: height 0.5s ease, opacity 0.0s ease 0.5s, visibility 0.0s ease 0.5s;
transition: height 0.5s ease, opacity 0.0s ease 0.5s, visibility 0.0s ease 0.5s;
-o-transition: height 0.5s ease, opacity 0.0s ease 0.5s, visibility 0.0s ease 0.5s;
-moz-transition: height 0.5s ease, opacity 0.0s ease 0.5s, visibility 0.0s ease 0.5s;
}
#nav ul li a:hover ul li {
visibility: visible;
opacity: 1;
height: 1em;
-webkit-transition:height 0.5s ease;
transition:height 0.5s ease;
-o-transition:height 0.5s ease;
-moz-transition:height 0.5s ease;
}<div id="wrapper"><div id="logo"></div><label for="toggle">menu</label>
<input type="checkbox" id="toggle">
<div id="nav">
<ul>
<li><a href="#">Home<ul><li></li></ul></a></li>
<li><a href="#">About<ul><li></li></ul></a></li>
<li><a href="#">Products<ul><li></li></ul></a></li>
<li><a href="#">FAQ<ul><li></li></ul></a></li>
<li><a href="#">Support<ul><li></li></ul></a></li>
<li><a href="#">Contact<ul><li></li></ul></a></li>
</ul>
</div>
test
</div>
答案 0 :(得分：3)
只需从媒体查询中的max-height: 20em;移除#nav即可。
* {
margin: 0;
padding: 0;
border: 0;
list-style: none;
font-size: 100%;
font: inherit;
vertical-align: baseline;
}
/*RESET*/
body {
font: 1em Arial, Helvetica, sans-serif;
}
#wrapper {
max-width: 960px;
margin: auto;
}
#nav {
display: block;
max-height: 0em;
overflow: hidden;
transition: max-height 0.5s ease;
-webkit-transition: max-height 0.5s ease;
-moz-transition: max-height 0.5s ease;
-o-transition: max-height 0.5s ease;
}
input[type="checkbox"] {
position: absolute;
margin-top: -100em;
}
input[type="checkbox"]:checked + #nav {
max-height: 20em;
}
label {
background: #9c0;
cursor: pointer;
display: block;
overflow: auto;
padding-left: 1em;
background-color: #9C0;
background: -moz-linear-gradient(top, #99cc00 0%, #85b100 100%);
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, #99cc00), color-stop(100%, #85b100));
background: -webkit-linear-gradient(top, #99cc00 0%, #85b100 100%);
background: -o-linear-gradient(top, #99cc00 0%, #85b100 100%);
background: -ms-linear-gradient(top, #99cc00 0%, #85b100 100%);
background: linear-gradient(to bottom, #99cc00 0%, #85b100 100%);
filter: progid: DXImageTransform.Microsoft.gradient(startColorstr='#99cc00', endColorstr='#85b100', GradientType=0);
-webkit-touch-callout: none;
-webkit-user-select: none;
-khtml-user-select: none;
-moz-user-select: none;
-ms-user-select: none;
user-select: none;
color: #FFF;
font-size: 1.6em;
line-height: 2.6em;
}
label:after {
content: "\f039";
float: right;
background-color: #669900;
padding: 0.2em 0.3em 0.1em;
margin: 0.5em;
font: 1.2em FontAwesome;
border-radius: 0.3em;
-webkit-box-shadow: inset 0em 0.1em 0.2em 0em rgba(0, 0, 0, 0.3);
-moz-box-shadow: inset 0em 0.1em 0.2em 0em rgba(0, 0, 0, 0.3);
box-shadow: inset 0em 0.1em 0.2em 0em rgba(0, 0, 0, 0.3);
}
#nav ul li a {
background: #690;
border: solid #90c12f;
border-width: 1px 0 0;
text-decoration: none;
padding: 1em;
display: block;
color: #FFF;
}
#nav ul li a:hover,
#nav ul li a:active {
background: #abd728;
}
@media screen and (min-width: 479px) {
.d----onttouchshituntilthispoin----t {} label {
display: none;
}
#nav {
display: table;
width: 100%;
overflow: auto;
}
#nav ul {
display: table-row;
}
#nav ul li {
display: table-cell;
}
#nav ul li a {
color: #000;
position: relative;
text-align: center;
text-indent: 20px;
border: solid #000;
border-width: 0 1px 0 0;
line-height: 3.4em;
padding: 0px 20px 0px 0px;
transition: all 0.5s ease;
-webkit-transition: all 0.5s ease;
-o-transition: all 0.5s ease;
-moz-transition: all 0.5s ease;
}
#nav ul li:last-child a {
border: none
}
#nav ul li a:hover {
position: relative;
text-indent: 0px;
padding-right: 40px;
}
#nav ul li a:before {
font-family: FontAwesome;
content: "\f078";
position: absolute;
right: 1em;
margin-top: -0.85em;
visibility: hidden;
opacity: 0;
-webkit-transition: all 0.5s ease;
transition: all 0.5s ease;
-o-transition: all 0.5s ease;
-moz-transition: all 0.5s ease;
}
#nav ul li a:hover:before {
margin-top: 0em;
visibility: visible;
opacity: 1;
}
#nav ul li a ul li {
position: absolute;
background: #FF0;
display: block;
width: 100%;
height: 0em;
visibility: hidden;
opacity: 0;
border-radius: 0px 0px 5px 5px;
-moz-border-radius: 0px 0px 5px 5px;
-webkit-border-radius: 0px 0px 5px 5px;
-webkit-transition: height 0.5s ease, opacity 0.0s ease 0.5s, visibility 0.0s ease 0.5s;
transition: height 0.5s ease, opacity 0.0s ease 0.5s, visibility 0.0s ease 0.5s;
-o-transition: height 0.5s ease, opacity 0.0s ease 0.5s, visibility 0.0s ease 0.5s;
-moz-transition: height 0.5s ease, opacity 0.0s ease 0.5s, visibility 0.0s ease 0.5s;
}
#nav ul li a:hover ul li {
visibility: visible;
opacity: 1;
height: 1em;
-webkit-transition: height 0.5s ease;
transition: height 0.5s ease;
-o-transition: height 0.5s ease;
-moz-transition: height 0.5s ease;
}<div id="wrapper">
<div id="logo"></div>
<label for="toggle">menu</label>
<input type="checkbox" id="toggle">
<div id="nav">
<ul>
<li><a href="#">Home<ul><li></li></ul></a>
</li>
<li><a href="#">About<ul><li></li></ul></a>
</li>
<li><a href="#">Products<ul><li></li></ul></a>
</li>
<li><a href="#">FAQ<ul><li></li></ul></a>
</li>
<li><a href="#">Support<ul><li></li></ul></a>
</li>
<li><a href="#">Contact<ul><li></li></ul></a>
</li>
</ul>
</div>
test
</div>