* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    border: 0;
}

/* 如果基本宽度是100，那么 1rem=100px(设计稿px) 假如设计稿宽度是 750px,
开发以iphone6/7/8为例，宽度是375，如果想1rem=100px(设计稿px)，那么fontSize=375/750*100=50px; */

html {
    font-size: 100px;
}

html,
body {
    width: 100%;
    height: 100%
}

::after,
::before {
    box-sizing: border-box;
}

img {
    border: 0;
}

ul,
li {
    list-style: none;
}

em,
i {
    font-style: normal;
}

a {
    text-decoration: none;
}

input,
button,
select,
option {
    border: none;
    list-style: none;
    outline: none;
    background-color: transparent;
}

textarea {
    outline: none;
}

button {
    cursor: pointer;
}