.box-main {
    margin: 10px auto;
    padding: 50px 40px;
    width: 1080px;
    background-color: #EEF3FA;
}
.menu-float-left, menu-float-right {
    display:none;
}

h1 {
    font-size: 25px;
    font-weight: normal;
    color: #444;
    padding-bottom: 3px;
    border-bottom: solid 1px #ccc;
    margin-bottom: 10px;
}

#myOperaArea {
    float: right;
    margin: 0;
    padding: 200px 0 0 0;
    width: 420px;
    border: solid 0 red;
    font-size: 15px;
    color: #444;
}

    #myOperaArea button {
        min-width: 60px;
        padding: 2px 5px;
    }

    #myOperaArea p {
        margin: 15px auto 10px auto;
        line-height: 25px;
        height: auto;
    }

        #myOperaArea p span {
            color: dodgerblue;
        }

    #myOperaArea input {
        margin: 0;
        padding: 0 0 0 3px;
        font-size: 14px;
        height: 25px;
        width: 100%;
    }

#myScreenShotArea {
    position: relative;
    float: left;
    margin: 0;
    padding: 0;
    overflow: hidden;
    font-size: 18px;
    font-weight: bold;
    line-height: normal;
    letter-spacing: 1px;
    background: url(images/bg2025.jpg) no-repeat top center;
    width: 540px; /*背景图的高度和宽度*/
    height: 1018px;
}

    #myScreenShotArea > div {
        /* 垂直及水平居中 */
        display: flex;
        justify-content: center;
        align-items: center;
        text-align: center;
        border-bottom: solid 0px #ccc;
        line-height:normal;
    }
       /* 参展企业 */
        #myScreenShotArea > div:first-child {
            position: absolute;
            top: 410px;
            left: 20px;
            width: 500px;
            height: 80px;
            /* 字号及颜色 */
            font-size: 36px;
            color: #000;
            font-weight: bold;
            letter-spacing: 1px;
        }
        /* 展位号 */
        #myScreenShotArea > div:nth-child(2) {
            position: absolute;
            top: 493px;
            left: 170px;
            width: 213px;
            height: 31px;
            /* 字号及颜色 */
            font-size: 21px;
            color: #fff;
            font-weight: normal;
        }  

@media only screen and (max-width: 840px) {
    .box-main {
        margin: 0 auto;
        padding: 0;
        width: 100%;
        background-color: #fff;
    }

    #myScreenShotArea {
        float: none;
    }

    #myOperaArea {
        float: none;
        width: 100%;
        padding: 5px 5px 50px 5px;
    }
}