/* 统一处理 */
*, *::before, *::after {
    -webkit-box-sizing: border-box;
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}
html {
    line-height: 1.5;
    font-size: 15px;
    font-family: sans-serif;
    height: 100%;
}
body {
    height: 100%;
}

iframe {
    border-width: 0;
}