body,
button,
input,
p,
li,
ol,
ul,
div,
section,
article,
td,
th,
span,
textarea,
form,
footer,
header,
nav,
main,
address,
aside,
pre,
canvas {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    overflow: hidden;
}

li {
    list-style: none;
}

/* 定义滚动条高宽及背景
 高宽分别对应横竖滚动条的尺寸 */
::-webkit-scrollbar {
    width: 4px;
    height: 4px;
}

/* 定义滚动条轨道
  内阴影+圆角 */
::-webkit-scrollbar-track {
    background-color: transparent;
}

/* 定义滑块
  内阴影+圆角 */
::-webkit-scrollbar-thumb {
    border-radius: 4px;
    background-color: #ddd;
}