单击一个按钮后，我的div会向下滑动。此功能正常运行，但当前下拉菜单部分已在页面加载时切换。在单击该按钮之前，如何隐藏它？
JSFiddle链接：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>最佳答案
让您的默认HTML以<div class="slide closed" id="slide">开头。 。 。如果切换代码有效（如您所述）并且基于CSS定义，则默认情况下具有closed类的位置应在页面加载时将其置于关闭状态。