下面是css修改滚动条默认样式的代码：

　　html代码

<div class="inner">
<div class="innerbox">
<p style="height:200px;">这是内容111</p>
<p style="height:400px;">这里是内容222</p>
<p>这里是内容333</p>
</div>
</div>

　　css代码

　　　　.inner{
width: 265px;
height: 400px;
position: absolute;
top: 33px;
left: 13px;

overflow:hidden;
}
.innerbox{
overflow-x: hidden;
overflow-y: auto;
color: #000;
font-size: .7rem;
font-family: "\5FAE\8F6F\96C5\9ED1",Helvetica,"黑体",Arial,Tahoma;
height: 100%;
}

.innerbox::-webkit-scrollbar {
width: 4px;
height: 4px;
}
.innerbox::-webkit-scrollbar-thumb {
border-radius: 5px;
-webkit-box-shadow: inset 0 0 5px rgba(0,0,0,0.2);
background: rgba(0,0,0,0.2);
}
.innerbox::-webkit-scrollbar-track {
-webkit-box-shadow: inset 0 0 5px rgba(0,0,0,0.2);
border-radius: 0;
background: rgba(0,0,0,0.1);
}