.mainStyle {
    width: 980px;
    padding: 40px 0;
    /*border:dotted 2px red;*/
    position: relative;
    float: left;
}

    .mainStyle ul {
        width: 100%;
    }

        .mainStyle ul li {
            width: 202px;
            height: 126px;
            border: 3px solid #ddd;
            float: left;
            margin-right: 23px;
            margin-bottom: 23px;
        }

            .mainStyle ul li img {
                width: 202px;
                height: 126px;
                vertical-align: top;
                display: inline-block;
            }