#main-container {
    font-family: 'Helvetica';
    width: 95%;
    max-width: 1400px;
    margin: auto;
}
#contents {
    height: 1850px;
    min-height: 300px;
    color: #000000;
    background-color :#ffffff;
    padding-top: 60px;
}
/* 見出し */
.headline {
    font-size: 35px;
    text-align: left;
}
/*　説明文　*/
.content {
    font-size: 15px;
    margin: 50px 0;
    color: #000000;
}
.containers {
    text-align: center;
    padding-top: 10px;
}
/* 新xlaboシステムの中の写真 */
.image-1 {
    margin-left: 40px;
    float: left;
}
.image-2 {
    margin-right: 40px;
    margin-top: 50px;
    float: right;
}
.image-3 {
    margin-left: 40px;
    margin-top: 50px;
    padding-bottom: 90px;
    float: left;
}
.back-btn,
a.back-btn  {
    color: #fff;
    font-size: 1.0em;
    background-color:#191986;
    border: 1px;
    height: 35px;
    width: 90px;
    margin: 30px;
    float: right;
    clear: both;
}
.back-btn:hover,
a.back-btn:hover {
    color: #fff;
    background: #000066;
}

@media screen and (max-width: 950px) {
    #main-container {
        flex: 100%;
        max-width: 100%;
    }
    /* 見出し */
    .headline {
        font-size: 18px;
        font-weight: bold;
        line-height: 1.3;
        margin-bottom: 0px;
    }
    /*　説明文　*/
    #contents {
        height: 1700px;
        margin: 20px 20px;
        min-height: 300px;
        padding-top: 5px;
    }/*　説明文　*/
    .content {
        margin-top: 5px;
    }  
      

}
@media screen and (max-width: 600px) {
    #main-container {
        flex: 100%;
        max-width: 100%;
    }
    /* 見出し */
    .headline {
        font-size: 18px;
        font-weight: bold;
        line-height: 1.3;
        margin-bottom: 0px;
    }
    /*　説明文　*/
    #contents {
        height: 1500px;
        margin: 20px 20px;
        min-height: 300px;
        padding-top: 5px;
    }/*　説明文　*/
    .content {
        margin-top: 5px;
    }  
      

}