我正在尝试获取一个联系表单来推动响应式屏幕尺寸的变化。如果您查看下面的JS Fiddle链接，您会看到当设置在移动级别屏幕时，它不会将其推下，但只是重叠联系表单。
下面是我的HTML和CSS。
HTML：
<div id="menuBackground">
<div id="menuContainer">
<label for="show-menu" class="show-menu">Show Menu</label>
<input type="checkbox" id="show-menu" role="button" />
<ul id="menu">
<li><a href="#">Home</a></li>
<li>
<a href="#">About</a>
<ul class="hidden">
<li><a href="#">Who We Are</a></li>
<li><a href="#">What We Do</a></li>
</ul>
</li>
<li>
<a href="#">Portfolio</a>
<ul class="hidden">
<li><a href="#">Photography</a></li>
<li><a href="#">Web User Interface Design</a></li>
<li><a href="#">Illustration</a></li>
</ul>
</li>
<li><a href="#">News</a></li>
<li><a href="#">Contact</a></li>
</ul>
</div>
</div>
<div>
<form action="#">
<header>
<h2>Example Responsive Form</h2>
<div>This form breaks at 600px and goes from a left-label form to a top-label form. At above 1200px, the labels align right.</div>
</header>
<div>
<label class="desc" id="title1" for="Field1">Full Name</label>
<div>
<input id="Field1" name="Field1" type="text" class="field text fn" value="" size="8" tabindex="1">
</div>
</div>
<div>
<label class="desc" id="title3" for="Field3">
Email
</label>
<div>
<input id="Field3" name="Field3" type="email" spellcheck="false" value="" maxlength="255" tabindex="3">
</div>
</div>
<div>
<label class="desc" id="title4" for="Field4">
Message
</label>
<div>
<textarea id="Field4" name="Field4" spellcheck="true" rows="10" cols="50" tabindex="4"></textarea>
</div>
</div>
<div>
<fieldset>
<legend id="title5" class="desc">
Select a Choice
</legend>
<div>
<input id="radioDefault_5" name="Field5" type="hidden" value="">
<div>
<input id="Field5_0" name="Field5" type="radio" value="First Choice" tabindex="5" checked="checked">
<label class="choice" for="Field5_0">First Choice</label>
</div>
<div>
<input id="Field5_1" name="Field5" type="radio" value="Second Choice" tabindex="6">
<label class="choice" for="Field5_1">Second Choice</label>
</div>
<div>
<input id="Field5_2" name="Field5" type="radio" value="Third Choice" tabindex="7">
<label class="choice" for="Field5_2">Third Choice</label>
</div>
</div>
</fieldset>
</div>
<div>
<fieldset>
<legend id="title6" class="desc">
Check All That Apply
</legend>
<div>
<div>
<input id="Field6" name="Field6" type="checkbox" value="First Choice" tabindex="8">
<label class="choice" for="Field6">First Choice</label>
</div>
<div>
<input id="Field7" name="Field7" type="checkbox" value="Second Choice" tabindex="9">
<label class="choice" for="Field7">Second Choice</label>
</div>
<div>
<input id="Field8" name="Field8" type="checkbox" value="Third Choice" tabindex="10">
<label class="choice" for="Field8">Third Choice</label>
</span>
</div>
</fieldset>
</div>
<div>
<label class="desc" id="title106" for="Field106">
Select a Choice
</label>
<div>
<select id="Field106" name="Field106" class="field select medium" tabindex="11">
<option value="First Choice">First Choice</option>
<option value="Second Choice">Second Choice</option>
<option value="Third Choice">Third Choice</option>
</select>
</div>
</div>
<div>
<div>
<input id="saveForm" name="saveForm" type="submit" value="Submit">
</div>
</div>
</form>
</div>
CSS：
/* Start General Styling */
* {
-webkit-box-sizing: border-box;
-moz-box-sizing: border-box;
box-sizing: border-box;
}
body {
margin: 0;
}
/* End General Styling */
#menuBackground {
background: #2f3036;
width: 100%;
height: 50px;
text-align: center;
}
#menuContainer {
text-align: center;
}
/*Strip the ul of padding and list styling*/
ul {
list-style-type: none;
margin: 0;
padding: 0;
}
/*Create a horizontal list with spacing*/
li {
display: inline-block;
vertical-align: top;
margin-right: 1px;
}
/*Style for menu links*/
li a {
display: block;
min-width: 140px;
height: 50px;
text-align: center;
line-height: 50px;
font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
color: #fff;
background: #2f3036;
text-decoration: none;
font-size: 1rem;
}
/*Hover state for top level links*/
li:hover a {
background: #19c589
}
/*Style for dropdown links*/
li:hover ul a {
background: #f3f3f3;
color: #2f3036;
height: 40px;
line-height: 40px
}
/*Hover state for dropdown links*/
li:hover ul a:hover {
background: #19c589;
color: #fff
}
/*Hide dropdown links until they are needed*/
li ul {
position: absolute;
display: none
}
/*Make dropdown links vertical*/
li ul li {
display: block;
}
/*Prevent text wrapping*/
li ul li a {
width: auto;
min-width: 100px;
padding: 0 20px
}
/*Display the dropdown on hover*/
ul li a:hover + .hidden,
.hidden:hover {
display: block
}
/*Style 'show menu' label button and hide it by default*/
.show-menu {
font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
text-decoration: none;
color: #fff;
background: #19c589;
text-align: center;
padding: 16px 0;
display: none;
width: 100%!important
}
/*Hide checkbox*/
input[type=checkbox] {
display: none
}
/*Show menu when invisible checkbox is checked*/
input[type=checkbox]:checked ~ #menu {
display: block;
margin: 0 auto
}
/*Responsive Styles*/
@media screen and (max-width: 760px) {
/*Make dropdown links appear inline*/
ul {
position: static;
display: none;
white-space: initial;
}
/*Create vertical spacing*/
li {
margin-bottom: 1px
}
/*Make all menu links full width*/
ul li,
li a {
width: 100%
}
/*Display 'show menu' link*/
.show-menu {
display: block
}
}
form header {
margin: 0 0 20px 0;
}
form header div {
font-size: 90%;
color: #999;
}
form header h2 {
margin: 0 0 5px 0;
}
form > div {
clear: both;
overflow: hidden;
padding: 1px;
margin: 0 0 10px 0;
}
form > div > fieldset > div > div {
margin: 0 0 5px 0;
}
form > div > label,
legend {
width: 25%;
float: left;
padding-right: 10px;
}
form > div > div,
form > div > fieldset > div {
width: 75%;
float: right;
}
form > div > fieldset label {
font-size: 90%;
}
fieldset {
border: 0;
padding: 0;
}
input[type=text],
input[type=email],
input[type=url],
input[type=password],
textarea {
width: 100%;
border-top: 1px solid #ccc;
border-left: 1px solid #ccc;
border-right: 1px solid #eee;
border-bottom: 1px solid #eee;
}
input[type=text],
input[type=email],
input[type=url],
input[type=password] {
width: 50%;
}
input[type=text]:focus,
input[type=email]:focus,
input[type=url]:focus,
input[type=password]:focus,
textarea:focus {
outline: 0;
border-color: #4697e4;
}
@media (max-width: 600px) {
form > div {
margin: 0 0 15px 0;
}
form > div > label,
legend {
width: 100%;
float: none;
margin: 0 0 5px 0;
}
form > div > div,
form > div > fieldset > div {
width: 100%;
float: none;
}
input[type=text],
input[type=email],
input[type=url],
input[type=password],
textarea,
select {
width: 100%;
}
}
@media (min-width: 1200px) {
form > div > label,
legend {
text-align: right;
}
}
这两个响应设置是否导致它不起作用？
答案 0 :(得分：0)
您只需要删除此类的height: 50px：
#menuBackground {
background: #2f3036;
width: 100%;
// removed height
text-align: center;
}
您已将容器设置为最大高度50px，因此即使菜单展开，容器仍保持50px。所以你看到的只是容器溢出。
注意
不要将ID用于样式元素 - 请参阅此处LINK