我一直在网站上工作，我需要显示一个粘性页脚。我可以做到这一点，它在其他浏览器中运行良好，但在Safari中没有。在Safari中看不到页脚。下面是我的页脚HTML和CSS。
<!DOCTYPE html>
<html>
<head>
<style>
.footer{
background-image: url(../images/footer_bck.png);
height: 23em;
min-width: 980px;
position: fixed;
width: 100%;
bottom: 0;
z-index: -1;
-webkit-backface-visibility: hidden;
backface-visibility: hidden;
}
.footer_logo{
position: relative;
left: 0;
right: 0;
margin-left: 45%;
margin-top: 2%;
}
.footer_line{
margin-top: 15px;
margin-left: 2%;
}
.footer_list li{
float: right;
list-style-type: none;
margin-right: 66px;
padding-top: 10px;
}
.footer_list li a {
text-decoration: none;
color: #fff;
font-size: 11px;
font-family: "museo_sans900";
}
.footer-text h4{
text-decoration: none;
font-family: 'Open Sans', sans-serif;
color: #fff;
font-size: 12px;
margin-left: 85px;
margin-top: -3%;
}
</style>
</head>
<body>
.......
<footer class="footer large-12 medium-12 small-12 columns">
<img class="footer_logo" src="images/footer_webable.png">
<img class="footer_line" src="images/footer_line.png">
<div>
<h4>
<ul class="footer_list large-12 medium-12 small-12 columns">
<li><a href="#">Contact</a></li>
<li><a href="#">The Bable blog</a></li>
<li><a href="#">Careers</a></li>
</ul>
</h4>
<div class="footer-text large-12 medium-12 small-12 columns"><h4>2015 Webable Digital. All Rights Reserved.</h4></div>
</div>
</footer>
</body>
</html>
请帮我弄清楚为什么在徒步旅行中看不到页脚。