html页面滚动到一定位置显示回到顶部按钮

回到顶部按钮在很多页面中都会用到，具体实现效果如下：

当页面滚动到一定位置时，页面右下侧出现固定按钮：

当鼠标移到按钮上方时，有一定的动画效果：

<div class="t-right-bar">
<div class="t-bar-support" data-open-online-form><a href="index.php?a=support&c=html">技术支持</a></div>
<div class="t-bar-rocket" id="back-to-top">返回顶部</div>
</div>

.t-right-bar {
position: fixed;
right: 0;
bottom: 10%;
width: 48px;
height: 48px;
z-index: 1000;
cursor: pointer;
}

.t-right-bar > div {
float: left;
height: 36px;
margin-bottom: 1px;
border-radius: 20px 0 0 20px;
color: #fff;
padding-left: 100%;
clear: both;
white-space: nowrap;
font-size: 13px;
line-height: 36px;
font-style: normal;
background-color: #aaa;
background-repeat: no-repeat;
background-position: 12px center;
transition: transform .2s cubic-bezier(.215, .61, .355, 1), padding .2s cubic-bezier(.215, .61, .355, 1), margin .2s cubic-bezier(.215, .61, .355, 1), background-color .2s cubic-bezier(.215, .61, .355, 1)
}

.t-right-bar > div.active, .t-right-bar > div:hover {
transform: translateX(-100%);
padding-left: 45px;
padding-right: 10px;
margin-left: 48px;
background-color: #23a0e1;
text-decoration: none;
color: #fff
}

.t-right-bar .t-bar-support {
background-image: url(../img/icon/support_1.svg);   //按钮图标
background-position: 14px center;
}

.t-right-bar .t-bar-rocket {
background-image: url(../img/icon/rocket_1.svg);  //按钮图标
background-position: 19px center;
}

.t-bar-support a{
color: white;
}

.t-bar-support a:hover{
color: #fff
}

$(".t-right-bar").hide();
$(function () {
$(window).scroll(function () {
if ($(window).scrollTop() > 100) {
$(".t-right-bar").fadeIn(500);
}
else {
$(".t-right-bar").fadeOut(500);
}
});

$("#back-to-top").click(function () {
$('body,html').animate({scrollTop: 0}, 100);
return false;
});
});