任务要求：

简单对网页进行分割布局，基本思路上中下三部分，然后在每一部分细分

/* CSS Document */
*{
    margin: 0;
    padding: 0;
}
#body{
    margin: 0 auto;
    width: 905px;
height: 1200px;
}
/*顶部div*/
#top{
    width: 100%;
    height: 75px;
}
/*中间div*/
#content_top{
    width: 100%;
    height: 260px;
    margin-top: 10px;
}
.logo{
    background-image:url(../images/logo.jpg);
    background-repeat: no-repeat;
    height: 75px;
    width: 185px;
    background-position:0 50%;
    display: inline-block;
    float: left;/*即使给div设置了宽，依然独占一行，所以要设置成行内元素*/
}
.search{
    width: 277px;    
    display: inline-block;
    float: left;
    margin-left: 638px; 
    margin-top: -36px;
    font-size: 13px;
}
.button{
    background:none;
    background-image: url(../images/btn_srh.gif);
    width: 58px;
    height: 23px;
    border: none;
}
.text{
    background: none;
    background-image: url(../images/srh_bg.gif);
}
/*顶部背景图*/
#back_top{
    height: 66px;
    width: 100%;
    background-image:url(../images/../images/nav_bg.gif);
    background-repeat: repeat-x;
}
/*导航栏*/
.back_a{
    float: left;
    height: 66px;
    width: 4px;
    background:url(../images/../images/nav_bg.gif)  no-repeat;
    background-position: 0 33%;
    overflow: hidden;
}
.back_b{
    height: 66px;
    width: 4px;
    background:url(../images/../images/nav_bg.gif)  no-repeat;
    background-position: -6px -66px;
    overflow: hidden;
    float: right;
}
.back_one ul li{
    list-style: none;
    float: left;
    margin: 7px 25px;
}
.back_one ul li a{
    text-decoration: none;
    color: white;
    font-weight:bold;
}
.back_one ul li a span{
    background-image: url(../images/../images/nav_bg.gif);
overflow: hidden;
    background-position: -2px -132px;
    color: #000000;
    text-align: center;
    display: inline-block;
    height: 30px;
    width: 94px;
    }
.back_two ul li{
    font-size: 12px;
    list-style: none;
    float: left;
    margin-left: 29px;
    margin-top: 6px;
}
.back_two ul{
    position: absolute;    /* 添加absoulute目的是脱离文本流，不受上层影响*/
    top: 35px;
}
/*中部部内*/
.content_left{
    height: 255px;
    width: 272px;
display: inline-block;
    float: left;
}
.sign_shang{
    height: 39px;
    width: 131px;
    background-image: url(../images/../images/btn_login.gif);
    display: inline-block;
    float: left;
}
.sign_ren{
    height: 39px;
    width: 131px;
    background-image: url(../images/../images/../images/btn_login1.gif);
    display: inline-block;
    float: left;
    margin-left: 6px;
}
/*上部中间*/
.content_middle{
    height: 255px;
    width: 390px;
    background-image: url(../images/../images/hot_bg.gif);
    background-repeat: no-repeat;
    display: inline-block;
    float: left;
    margin-left: 5px;
}
.content_middle .p{
    font-size: 18px;
    font-weight: bold;
    text-align: center;
    margin-top: 15px;
}
.content_middle p{
    font-size: 13px;
    margin: 15px;
}
.content_middle ul li{
    list-style-image:url(../images/wuxu.jpg);
    font-size: 13px;
    margin:3px  36px 0;
}
.content_middle span{
    display: inline-block;
    float: right;
    color: #7B9F11;
}
.content_middle a{
    text-decoration: none;
    color: #000000;
}
.conten_middle .xuxian{
border: 1px #CCCCCC dashed;
    width: 350px;
    height: 80px;
    }                                                     /*不显示,设置边框无用*/
/*上部右方*/
.content_right{
    height: 255px;
    width: 230px;
float: left;
    margin-left: 7px;    
    background-image: url(../images/side_bg.gif);
}
.right_one{    
    height: 28px;
    width: 100%;
    line-height: 28px;
    margin: auto;    
}
.right_two{
    height: 74px;
    width: 207px;
    background-image: url(../images/../images/icon2.gif) ;
    background-repeat: no-repeat;
    background-position: 10px 11px;
    border-bottom-style:dashed;
    border-width: 0.1px;
    margin-left: 4px;
    font-size: 14px;
}
.yuyin {
    position: relative;
    top:17px;
    right: -62px;
}
.right_three{
    height: 74px;
    width: 207px;
    background-image: url(../images/../images/icon2.gif) ;
    background-repeat: no-repeat;
    background-position: 10px -60px;
    border-bottom-style:dashed;
    border-width: 0.1px;
    margin-left: 4px;
    font-size: 14px;
}
.right_four{
    height: 74px;
    width: 207px;
    background-image: url(../images/../images/icon2.gif) ;
    background-repeat: no-repeat;
    background-position: 10px -134px;
margin-left: 4px;
    font-size: 14px;
}
.right_five{
    height: 5px;
    width: 100%;
    background-image: url(../images/side_bg.gif);
    background-position: 0% 100%;
}
/*内容第二部分*/
#content_two{
    height: 630px;
    width: 100%;
margin:auto;
}
.images{
    border: 1px solid #DBDBDB;
    height: 293px;
    width: 660px;
display: inline-block;
    float: left;
    margin-top: 10px;
    /*为什么之右images也浮动起来，下面的才能上来*/
}    
.zuobian_top{
    height: 30px;
    width: 100%;
    background-color: #F7F7F7;
    line-height: 30px;
}
.xiangce ul li{
    list-style: none;
    float: left;
}
.xiangce ul li img{
    display: block;
    margin:0 auto;
}
.xiangce ul li a{
    display:block;
    text-align: center;
    margin: 20px 0px 0px 20px;
    text-decoration: none;
    color: #000000;
    font-size: 14px
}
/*企业历史左边的*/
.history_left{
    border: 1px solid #DBDBDB;
    height: 288px;
    width: 327px;
float: left;
    display:inline-block;
    margin-top: 10px;
}
.history_lefttop{
    height: 30px;
    width: 100%;
    background-color: #F7F7F7;
    line-height: 30px;
    background-image: url(../images/icon.gif) ;/*如何用img实现backgrondposition的效果*/
    background-repeat: no-repeat;
    background-position: 10px 5px;
    overflow: hidden;
}
.more{
    width: 70px;
    height: 30px;
    background-image: url(../images/icon.gif) ;
    background-repeat: no-repeat;
    background-position: 10px 5px;
    overflow: hidden;
    display: inline-block;
    float: right;
}
.history_leftcontent{
    font-size: 13px;
    margin: 17px;
    color: #A7A3A4;
}
.history_leftcontent .history_apple{
    margin-right: 15px;
    float: left;
}
.history_leftlist a{
    text-decoration: none;
    color: #000000;
}
.history_leftlist ul li{
    list-style-image:url(../images/wuxu.jpg);
    font-size: 13px;
margin:3px 0px 3px 32px;
}
.history_right{
    border: 1px solid #DBDBDB;
    height: 288px;
    width: 327px;
float: left;
    display: inline-block;
    margin-top: 10px;
    margin-left: 5px;
}
.history_righttop{
    height: 30px;
    width: 100%;
    background-color: #F7F7F7;
    line-height: 30px;
background-image: url(../images/icon.gif) ;/*如何用img实现backgrondposition的效果*/
    background-repeat: no-repeat;
    background-position: 10px 5px;
    overflow: hidden;
}
/*右边问答区*/
.questions{
    height: 434px;
    width: 229px;
    margin-top: 10px;
    font-size: 13px;
    display: inline-block;
    margin-left: 12px;
    background-image: url(../images/side_bg.gif);
    background-repeat: no-repeat;
    overflow: hidden;
    background-position: 0% 0%;
}
.que1{
    font-size: 16px;
    height: 28px;
    width: 100%;
    line-height: 28px;
    margin: auto;    
}
.que2,.que6{
    margin: 5px 5px 0px 30px;
}
.questions ul{
    list-style-image: url( ../images/wuxu.jpg);
    margin-bottom: 10px;
}
.que3{
    border: 1px dashed #DCDCDC;
    margin: 5px 5px 0px 30px;
    border-left-style: hidden;
    border-right-style: hidden;
}
.que4,.que5{
    border: 1px dashed #DCDCDC;
    margin: 5px 5px 0px 30px;
    border-left-style: hidden;
    border-right-style: hidden;
    border-top-style: hidden;
}
.que7{
    background-image: url(../images/side_bg.gif);
    background-position: 0% 100%;
    margin-top: -5px;
    margin-left: 0px;
    line-height: 33px;
}
.iphone{
    border: 1px solid #A29D9E;
    border-top-style: hidden;
    border-left-style: hidden;
    border-right-style: hidden;
    height: 142px;
    width: 226px;
    margin-left: 14px;
    display: inline-block;
    margin-top: 10px;
    background-image: url(../images/side_bg.gif);
    background-repeat: no-repeat;
    overflow: hidden;
    background-position: 0% 0%;
}
.iphone_top{
    font-size: 16px;
    height: 28px;
    width: 100%;
    line-height: 28px;
    margin: auto;
}
.ipone_image{
    height: 110px;
    width: 100%;
    background-image: url(../images/tel.gif);
}
/*顶部*/
#foot{
    width: 100%;
    height: 90px;
margin-top: -13px;
}
.foot_top{
    height: 30px;
    width: 100%;
    background-color: #AFAFAF;
}
.foot_top a{
    text-decoration: none;
    line-height: 30px;
    text-align: center;
    color: white;
}
.foot_foot{
    font-size: 13px;
    color: #666666；
}
span {
    color: red;
}
.back_two {
    position: relative;
}