.container {
    background-color: #fafafa;
    display: flex;
    flex-direction: column;
    align-items: center;
    /*width: 1200px;*/
}

.nav{
    position: fixed;
    width: 100%;
    height: 40px;
    top: 0;
    right: 0;
    background-color: rgba(0,0,0,0.6);
    display: flex;
    justify-content: space-around;
    align-items: center;
    /*padding: 0 100px;*/
    z-index: 666;
}
.nav .content{
    width: 1440px;
    display: flex;
    /*background-color: #00aa76;*/
    justify-content: flex-end;
}

.container .item{
    width: 1440px;
}

.container .a{
    background-image: url("https://heytalk-oa.oss-cn-beijing.aliyuncs.com/web-image/yyj/1.jpg");
    /*height: auto;*/
    height: 635px;
    /*position: relative;*/
}



a{
    color: white;
}

.container .b{
    background-image: url("https://heytalk-oa.oss-cn-beijing.aliyuncs.com/web-image/yyj/2.jpg");
    height: 500px;
}

.container .c{
    background-image: url("https://heytalk-oa.oss-cn-beijing.aliyuncs.com/web-image/yyj/3.jpg");
    height: 1504px;
}

.container .d{
    background-image: url("https://heytalk-oa.oss-cn-beijing.aliyuncs.com/web-image/yyj/4.jpg");
    height: 797px;
}

.container .e{
    background-image: url("https://heytalk-oa.oss-cn-beijing.aliyuncs.com/web-image/yyj/5.jpg");
    height: 1308px;
}

.container .f{
    background-image: url("https://heytalk-oa.oss-cn-beijing.aliyuncs.com/web-image/yyj/6.jpg");
    height: 839px;
    position: relative;
}

.f .beian{
    position: absolute;
    bottom: 0;
    height: 30px;
    line-height: 30px;
    background-color: rgba(0,0,0,0.5);
    color: white;
    width: 100%;
    text-align: center;
}