我有一个div，一旦点击一个按钮就滑下来。此功能正常工作，但目前下拉部分已在页面加载时切换。如何在单击按钮之前隐藏它？
JSFiddle Link：http://jsfiddle.net/maddiwu/xe6xtfqh/
.slide {
overflow-y: hidden;
max-width: 100%;
overflow-x: hidden;
max-height: 100vw;
/* approximate max height */
width:100%;
/*height: 45vw;*/
background:#2e2e2e;
transition-property: all;
transition-duration: 1s;
transition-timing-function: cubic-bezier(1, 1, 1, 1);
}
.slide.closed {
max-height: 0;
}
.banner7 {
width:80%;
background:#d8d8d8;
margin-top:1.5vw;
padding-top:2vw;
}
.banner8 {
width:80%;
background:#2e2e2e;
margin-top:1vw;
margin-left:10%;
padding-top:2vw;
}<center>
<div class="banner7" style="margin-bottom:0vw;margin-top:2vw;">
<h1 style="color:#B40404;font-size:2.5vw;margin:1.5vw;font-family:Futura;">MAIN SECTION</h1>
<p style="font-family:Helvetica Neue;font-size:1vw;color:back;margin-left:5vw; margin-right:5vw; text-align:center; margin-top:-1vw;margin-bottom:3vw;">Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa.</p>
<table style="width:95%; margin-left:2%;">
<tr>
<td>
<div style="background:white;width:21vw;margin-top:0vw;margin-bottom:2vw;padding:1vw;">
<h1 style="color:#b40404;font-size:1.5vw;font-family:Futura; text-align:center;margin-top:1vw;">SUB SECTION ONE</h1>
<p style="font-family:Helvetica Neue;font-size:1vw;color:#2e2e2e; text-align:center; margin-top:1vw;margin-bottom:1vw;">Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor.</p>
<center>
<img src="images/button.png" style="width:35%;height:3vw;margin-top:1vw; margin-bottom:1vw;" onmouseover="this.src='images/button-hover.png'" onmouseout="this.src='images/button.png'" onload="closed" onclick="document.getElementById('slide').classList.toggle('closed');" />
</center>
</div>
</td>
<td>
<div style="background:white;width:21vw;margin-top:0vw;margin-bottom:2vw;padding:1vw;">
<h1 style="color:#b40404;font-size:1.5vw;font-family:Futura; text-align:center;margin-top:1vw;">SUB SECTION TWO</h1>
<p style="font-family:Helvetica Neue;font-size:1vw;color:#2e2e2e; text-align:center; margin-top:1vw;margin-bottom:1vw;">Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor.</p>
<center>
<img src="images/button.png" style="width:35%;height:3vw;margin-top:1vw; margin-bottom:1vw;" onmouseover="this.src='images/button-hover.png'" onmouseout="this.src='images/button.png'" onclick="document.getElementById('slide').classList.toggle('closed');" />
</center>
</div>
</td>
<td>
<div style="background:white;width:21vw;margin-top:0vw;margin-bottom:2vw;padding:1vw;">
<h1 style="color:#b40404;font-size:1.5vw;font-family:Futura; text-align:center;margin-top:1vw;">SUB SECTION THREE</h1>
<p style="font-family:Helvetica Neue;font-size:1vw;color:#2e2e2e; text-align:center; margin-top:1vw;margin-bottom:1vw;">Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor.</p>
<center>
<img src="images/button.png" style="width:35%;height:3vw;margin-top:1vw; margin-bottom:1vw;" onmouseover="this.src='images/button-hover.png'" onmouseout="this.src='images/button.png'" onclick="document.getElementById('slide').classList.toggle('closed');" />
</center>
</div>
</td>
</tr>
</table>
</div>
</center>
<div>
<div class="slide" id="slide">
<div style="width:100%; background:#2e2e2e; padding:1vw; text-align:center;">
<table style="width:80%">
<tr>
<td>
<iframe style="margin-left:20%;width:45vw;height:30vw;" src="//www.youtube.com/embed/P7mS83pOPso" frameborder="0" allowfullscreen></iframe>
</td>
<td>
<center>
<h1 style="color:#d8d8d8;font-size:2.5vw;font-family:Futura; text-align:center;margin-top:0vw;margin-left:20vw;">DROP SECTION</h1>
<p style="font-family:Helvetica Neue;font-size:1vw;color:white;margin-left:11vw;margin-right:-8vw; text-align:center; margin-top:1vw;">Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Donec quam felis, ultricies nec, pellentesque eu, pretium quis, sem. Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Donec quam felis, ultricies nec, pellentesque eu, pretium quis, sem. Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Donec quam felis, ultricies nec, pellentesque eu, pretium quis, sem.</p>
</td>
</tr>
</table>
</center>
</div>
<div style="width:100%; background:#d8d8d8; padding:1vw; text-align:center;">
<center>
<center>
<h1 style="color:#b40404;font-size:2.5vw;font-family:Futura; text-align:center;margin-top:2vw;">DROP SECTION</h1>
<p style="font-family:Helvetica Neue;font-size:1vw;color:#2e2e2e;margin-right:10vw;margin-left:10vw; text-align:center; margin-top:-1vw;margin-bottom:2vw;">Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Donec quam felis, ultricies nec, pellentesque eu, pretium quis, sem.</p>
</center>
</td>
</tr>
</table>
</center>
</div>
</div>
</div>
</div>
<br>
答案 0 :(得分：3)
让您的默认HTML以<div class="slide closed" id="slide">开头。 。 。如果切换代码正常工作（如您所述）并且基于CSS定义，默认情况下使用closed类应该在页面加载时将其置于关闭状态。