移动端css，可是我还是不懂加上每段代码的含义，为什么样这样弄

Question

/*reset*/*,::before,::after{ margin: 0; padding: 0;    -webkit-tap-highlight-color: transparent;    -webkit-box-sizing: border-box;    box-sizing: border-box;}body{ font-size:14px; font-family: "microsoft yahei",sans-serif; color: #333;}a{ color: #333;    text-decoration: none;}a:hover{ text-decoration: none;}ul,ol{    list-style: none; }input{ border: none; outline: none; -webkit-appearance: none;}/*commom*/.f_left{ float: left;}.f_right{ float: right;}.clearfix::before;.clearfix::after{ content: ""; height: 0; line-height: 0; display: block;    visibility: hidden;    clear:both;}[class^="icon_"]{    background: url("../images/sprites.png") no-repeat;    background-size: 200px 200px;}.m_l10{    margin-left: 10px;}.m_r10{    margin-right: 10px;}.m_b10{    margin-bottom: 10px;}.m_t10{    margin-top: 10px;}

Answer 1

伪类，子类型选择器，好好看看《css权威指南》这本书，会对你有帮助。

望采纳！