Css-重置样式表

/* http://meyerweb.com/eric/tools/css/reset/
v2.0 | 20110126
License: none (public domain)
*/

html, body, div, span, applet, object, iframe,
h1, h2, h3, h4, h5, h6, p, blockquote, pre,
a, abbr, acronym, address, big, cite, code,
del, dfn, em, img, ins, kbd, q, s, samp,
small, strike, strong, sub, sup, tt, var,
b, u, i, center,
dl, dt, dd, ol, ul, li,
fieldset, form, label, legend,
table, caption, tbody, tfoot, thead, tr, th, td,
article, aside, canvas, details, embed, 
figure, figcaption, footer, header, hgroup, 
menu, nav, output, ruby, section, summary,
time, mark, audio, video {
    margin: 0;
    padding: 0;
    border: 0;
    font-size: 100%;
    font: inherit;
    vertical-align: baseline;
}
/* HTML5 display-role reset for older browsers */
article, aside, details, figcaption, figure, 
footer, header, hgroup, menu, nav, section {
    display: block;
}
body {
    line-height: 1;
}
ol, ul {
    list-style: none;
}
blockquote, q {
    quotes: none;
}
blockquote:before, blockquote:after,
q:before, q:after {
    content: '';
    content: none;
}
table {
    border-collapse: collapse;
    border-spacing: 0;
}

/图片水平垂直居中/

.valign{text-align:center;}
.valign img{vertical-align:middle;}
.valign:after{content:"";display:inline-block;height:100%;vertical-align:middle;}

/单行文本出现省略号/

.over{white-space:nowrap;overflow:hidden;text-overflow:ellipsis;}

/阻止margin-top向父元素传递/

.clear:before{content:"";display:table;}

/边框圆角属性/

.border-radius{border-radius:50%;}

/清除浮动/

.clear:after{content:"";clear:both;display:block;}

/弹性盒子,垂直居中，水平居中；水平两边分开对齐；换行；纵向排列；分开左右边距对齐;怪异盒模型/

.display{display:flex;align-items:center;justify-content:center;justify-content:space-between;flex-wrap:wrap;flex-direction:column; 
justify-content:space-around;box-sizing:border-box;}

/定位;1固定定位不占文档流，绝对定位不占文档流，相对定位占文档流/

.position{position:fixed;position:absolute;position:relative;}

/响应式移动端/

@media screen and (width:640px){
    html{font-size:64px;}    
}