#primary {
    position: relative;
    margin-bottom: 40px;
}

.post {
    margin: 65px auto 0;
    width: 1200px;
    position: relative;
}

.post:first-child {
    margin-top: 30px;
}

.post:nth-child(odd) {
    text-align: left;
}

.post:nth-child(even) {
    text-align: right;
}

.post .post_cover {
    display: inline-block;
    width: 680px;
    height: 440px;
    overflow: hidden;
    position: relative;
    z-index: 3;
}

.post_info {
    position: absolute;
    background: #fff;
    text-align: left;
    top: 20px;
    height: 398px;
    width: 498px;
    border: 1px solid #eaeaea;
}

.post_title {
    color: #1b1e21;
}

.post_c_time, .post_content{
    color: #6c757d;
    font-size: small;
}

.post:nth-child(odd) .post_info {
    left: 660px;
}

.post:nth-child(even) .post_info {
    right: 660px;
}

.post:nth-child(odd) .post_header {
    margin: 80px 0 0 80px;
}

.post:nth-child(even) .post_header {
    margin: 80px 80px 0 10px;
    text-align: right;
}

.post:nth-child(odd)  .post_content{
    margin: 10px 10px 0 80px;
}

.post:nth-child(even) .post_content{
    margin: 10px 80px 0 10px;
}