h1	{
    background:url("../img/title_about_us.jpg");	/*コーナーごとに指定*/
    background-size: 100% auto;
    background-position: center;
}

@media screen and (min-width:1101px){
#box_img1   {
    width: 50%;
    float: right;
}
#box_img1>img{
    width: 47%;
    margin-left: 2%;
}
#box_img2   {
    width: 50%;
    float: left;
    margin-bottom: 0;
}
#box_img2>img{
    width: 100%;
    padding-right: 20px;
}
.txt-box{
    overflow:hidden;
}
}

@media screen and (max-width:1100px) and (min-width:751px){
    #box_img1   {
        width: 50%;
        float: right;
    }
    #box_img1>img{
        width: 47%;
        margin-left: 2%;
    }
    #box_img2   {
        width: 50%;
        float: left;
        margin-bottom: 0;
    }
    #box_img2>img{
        width: 100%;
        padding-right: 20px;
    }
    .txt-box{
        overflow:hidden;
    }
}

@media screen and (max-width:750px){
    #box_img1   {
        width: 100%;
    }
    #box_img1>img{
        width: 47%;
        margin-left: 2%;
    }
    #box_img2   {
        width: 100%;
        margin-bottom: 0;
    }
    #box_img2>img{
        width: 100%;
    }
}