/* body{
background-image:url("https://qqpublic.qpic.cn/qq_public/0/0-2601951040-9C349E93EACBFAEBDB518AF2960C2BE9/0?fmt=jpg&size=17&h=506&w=900&ppv=1/0");
background-repeat:no-repeat;
background-size:100%;
background-attachment: fixed;
filter:alpha(opacity=70); -moz-opacity:0.7; -khtml-opacity: 0.7; opacity: 0.7;
} */