<body>
<!--側欄界面設計-->
<div id="mySidenav" class="sidenav">
<a href="javascript:void(0)" class="closebtn" onclick="closeNav()">×</a>
<a href="#">About</a>
<a href="#">Services</a>
<a href="#">Clients</a>
<a href="#">Contact</a>
</div>
<div id="main">
<h2>側邊欄實例 - 頁面主體向右移動</h2>
<p>點擊以下菜單圖標打開側邊欄，主體內容向右2偏移。主體內容添加黑色透明背景</p>
<span style="font-size:30px;cursor:pointer" onclick="openNav()">☰ open</span>
</div>
</body>
<script type="text/javascript">
/*打開側欄，修改側欄寬度，主體左跨度、背景透明度*/
function openNav() {
document.getElementById("mySidenav").style.width = "250px";
document.getElementById("main").style.marginLeft = "250px";
document.body.style.backgroundColor = "rgba(0,0,0,0.4)";
}
/*關閉側欄，恢復原始側欄寬度，主體左跨度、背景透明度*/
function closeNav() {
document.getElementById("mySidenav").style.width = "0";
document.getElementById("main").style.marginLeft= "0";
document.body.style.backgroundColor = "white";
}
</script>
<style>
@charset "utf-8";
/* CSS Document */
body {
font-family: "Lato", sans-serif;
transition: background-color .5s;
}
/*側邊欄選擇器*/
.sidenav {
height: 100%;
width: 0; /*原始寬度*/
position: fixed;
/*z-index、top、left共同控制側欄的懸浮（上方1，下方-1）*/
z-index: 1;
top: 0;
left: 0;
background-color: #111;
overflow-x: hidden;
transition: 0.5s; /*側欄延遲0.5s顯示*/
padding-top: 60px;
}
/*側邊欄標簽選擇器*/
.sidenav a {
padding: 8px 8px 8px 32px;
text-decoration: none;
font-size: 25px;
color: #818181;
display: block;
transition: 0.3s; /*標簽延遲0.3s顯示*/
}
/*側欄標簽和關閉按鈕光標的效果*/
.sidenav a:hover, .offcanvas a:focus{
color: #f1f1f1;
}
/*側欄和關閉按鈕的位置選擇器*/
.sidenav .closebtn {
position: absolute;
top: 0;
right: 25px;
font-size: 36px;
margin-left: 50px;
}
/*主體內容*/
#main {
transition: margin-left .5s;/*主體內容延遲0.5s整體y右移動*/
padding: 16px;
}
/*當文檔高度小於450px時，改變側欄的padding屬性和字體大小*/
@media screen and (max-height: 450px) {
.sidenav {padding-top: 15px;}
.sidenav a {font-size: 18px;}
}
</style>
