body {font-family:"微软雅黑";}

#wrapper{ margin:0 auto;position:relative;width:100%;height:100%;background:url(bg.jpg) no-repeat} 
/* position:relative是绝对定位关键，父级设置 */ 
.box1{position:relative; width:100%; left:0px; top:0px} 
.box2{position:relative; width:97%; height:50px; left:10px; top:10px;margin-bottom:5px;border:0px solid;border-radius:10px;background:#FFF;} 
.box7{position:relative; width:97%;  left:10px; top:10px;margin-bottom:5px;border:0px solid;} 
.box8{position:relative; width:97%; height:50px; left:10px; top:10px;margin-bottom:5px;border:0px solid;} 
.box6{text-align:center; vertical-align:middel;position:relative; width:97%; height:50px; left:10px; top:10px;margin-bottom:5px;border:0px solid;} 
.box9{text-align:center; vertical-align:middel;position:relative; width:97%; height:50px; left:10px; top:10px;margin-bottom:30px;border:0px solid;} 
.box10{text-align:left; vertical-align:middel;position:relative; width:97%; height:50px; left:10px; top:10px;margin-bottom:30px;border:0px solid;} 
.box12{text-align:left; vertical-align:middel;position:relative; width:97%; height:6px; left:10px; top:10px;margin-bottom:30px;border:0px solid;} 
.box11{position:relative; width:93%;  left:5px; top:10px;margin-bottom:5px;border:0px solid;} 
.box3{position:relative; width:100%; height:188px; left:0px; top:1400px} 
.box4{position:relative; width:100%; height:50px; left:5px; top:10px} 
.box5{ width: 200px; height: 100px; background: red; float: left; }
.box13{position:relative; width:97%; height:80px; left:10px; top:10px;margin-bottom:10px;border:0px solid;border-radius:10px;background:#FFF;} 
.box14{text-align:left; vertical-align:middel;position:relative; width:97%; height:50px; left:5px; top:10px;margin-bottom:30px;border:0px solid;} 
/* 三个小盒子使用position:relative同时设置宽度 高度 left right top bottom实现布局与准确定位 */ 

.a_demo_one {
    background-color:#238cba;
    padding:10px;
    position:relative;
    font-family: 'Open Sans', sans-serif;
    font-size:12px;
    text-decoration:none;
    color:#fff;
    border: solid 1px #831212;
    background-image: linear-gradient(bottom, rgb(171,27,27) 0%, rgb(212,51,51) 100%);
    border-radius: 5px;
}
.a_demo_one:active {
    padding-bottom:9px;
    padding-left:10px;
    padding-right:10px;
    padding-top:11px;
    top:1px;
    background-image: linear-gradient(bottom, rgb(171,27,27) 100%, rgb(212,51,51) 0%);
}