.about-box{
    width: 100%;
    position: relative;
    display: block;
    margin-top: 60px;
}
.about-btn-box{
    display: block;
    text-align: center;
    font-size: 0;
    box-sizing: border-box;
    padding-top: 50px
}
.about-btn{
    display: inline-block;
    width: 150px;
    font-size: 20px;
    letter-spacing: 1px;
    color: #6283a7;
    font-weight: bold;
    line-height: 46px;
    transition: all .3s linear;
    margin: 0 10px;
    border: 1px solid #6283a7;
}
.about-btn.about-now{
    background-color: #6283a7;
    color: #fff;
}
.about-btn:hover{
    background-color: #6283a7;
    color: #fff;
}

.about-introduction-t-box{
    margin-bottom: 15px;
}
.about-introduction-box{
    width: 1920px;
    max-width: 100%;
    display: block;
    margin: 0 auto;
    font-size: 0;
    box-sizing: border-box;
    padding: 15px 0;
    margin-top: 60px;
    background-color: #f5f5f5;
}
.about-introduction-t-img{
    width: 500px;
    height: 540px;
    display: inline-block;
    vertical-align: middle;
    background-repeat: no-repeat;
    background-size: cover;
    background-position: center;
    margin-right: 15px;
}
.about-introduction-t-aims{
    display: inline-block;
    vertical-align: middle;
    width: calc(100% - 1040px);
    box-sizing: border-box;
    padding: 0 10px;
}
.about-introduction-t-aims-title{
    font-size: 28px;
    font-weight: bold;
    color: #162148;
    letter-spacing: 2px;
}
.about-introduction-t-aims-text{
    font-size: 16px;
    color: #333;
    line-height: 2.5;
    letter-spacing: 1px;
}
.about-introduction-b-box{
    overflow: hidden;
}
.about-introduction-b-l-box{
    width: 724px;
    height: 100%;
    display: inline-block;
    vertical-align: top;
    margin-right: 15px;
}
.about-introduction-b-l-img{
    width: 100%;
    height: 360px;
    display: inline-block;
    vertical-align: top;
    background-repeat: no-repeat;
    background-size: cover;
    background-position: center;
}
.about-introduction-b-l-text-box{
    height: calc(800px - 360px);
    display: flex;
    flex-direction:column;
    justify-content:center;
    box-sizing: border-box;
    padding-left: 100px;
}
.about-introduction-b-l-text-title{
    font-size: 28px;
    font-weight: bold;
    color: #162148;
    letter-spacing: 2px;
}
.about-introduction-b-l-text{
    font-size: 16px;
    color: #333;
    line-height: 2.5;
    letter-spacing: 1px;
}
.about-introduction-b-l-text span{
    color: #000;
    font-weight: bold;
}
.about-introduction-b-l-text span:first-child{
    color: #ae8c4f;
    font-weight: bold;
}
.about-introduction-b-r-box{
    width: calc(100% - 739px);
    height: 800px;
    display: inline-block;
    vertical-align: top;
    background-repeat: no-repeat;
    background-size: cover;
    background-position: center;
}

.about-language-box{
    width: 95%;
    display: block;
    font-size: 0;
    margin: 20px auto;
    text-align: center;
}
.about-language{
    margin: 0 20px;
    font-size: 18px;
    color: #555;
    letter-spacing: 0.06em;
    position: relative;
    display: inline-block;
    vertical-align: middle;
    cursor: pointer;
    transition: all .3s linear;
}
.about-language.active,
.about-language:hover{
    color: #bf1925;
}
.about-language::after{
    content: "";
    width: 100%;
    height: 1px;
    background-color: #555;
    position: absolute;
    bottom: 0;
    left: 0;
}
.about-language.active::after,
.about-language:hover::after{
    background-color: #bf1925;
}
.about-menu-box{
    width: 1280px;
    max-width: 100%;
    display: block;
    font-size: 0;
    margin: 0 auto;
    min-height: calc(100vh - 200px);
    box-sizing: border-box;
    padding-bottom: 50px;
}
.about-menu{
    width: 100%;
    display: none;
    text-align: center;
}
.about-menu.active{
    display: block;
}
.rwd-about-language-now{
    display: none;
}
.about-image-box{
    width: 100%;
    box-sizing: border-box;
    padding: 20px 0;
}
.about-image-rl-box{
    width: 500px;
    max-width: 26%;
    height: calc((26vw - 3px) * (540 / 500));
    display: inline-block;
    vertical-align: top;
}
.about-image-c-box{
    width: 875px;
    max-width: 46%;
    height: calc((46vw - 11px) * (540 / 875));
    display: inline-block;
    vertical-align: top;
    margin: 0 1%;
}




@media only screen and (max-width: 1600px){
    .about-introduction-t-img{
        width: 400px;
        height: 432px;
    }
    .about-introduction-t-aims{
        width: calc(100% - 840px);
    }
}
@media only screen and (max-width: 1400px){
    .about-introduction-t-img{
        width: 300px;
        height: 324px;
    }
    .about-introduction-t-aims{
        width: calc(100% - 640px);
    }
    .about-introduction-t-aims-text{
        line-height: 2.2;
    }
    .about-introduction-b-l-box{
        width: 524px;
    }
    .about-introduction-b-l-img{
        height: calc(524px * (360 / 724));
    }
    .about-introduction-b-r-box{
        width: calc(100% - 539px);
        height: 584px;
    }
    .about-introduction-b-l-text-box{
        height: calc(584px - (524px * (360 / 724)));
        line-height: inherit;
    }
}
@media only screen and (max-width: 1200px){
    .about-introduction-t-img{
        width: 200px;
        height: 216px;
    }
    .about-introduction-t-aims{
        width: calc(100% - 440px);
        padding: 0;
    }
    .about-introduction-t-aims-title,
    .about-introduction-b-l-text-title{
        font-size: 24px;
    }
    .about-introduction-t-aims-text{
        line-height: 1.6;
    }
    .about-introduction-b-l-text{
        line-height: 2.2;
    }
    .about-introduction-b-l-box{
        width: 424px;
    }
    .about-introduction-b-l-img{
        height: calc(424px * (360 / 724));
    }
    .about-introduction-b-r-box{
        width: calc(100% - 439px);
        height: 516px;
    }
    .about-introduction-b-l-text-box{
        height: calc(516px - (424px * (360 / 724)));
        line-height: inherit;
        padding-left: 20px;
    }
}
@media only screen and (max-width: 1000px){
    .about-introduction-box{
        display: block;
        margin-top: 30px;
        padding: 10px 2%;
        box-sizing: border-box;
    }
    .about-introduction-t-aims{
        width: 100%;
        display: block;
        margin-top: 15px;
    }
    .about-introduction-t-aims-text{
        line-height: 2.2;
    }
    .about-introduction-t-img{
        width: calc(50% - (15px / 2));
        height: 432px;
    }
    .about-introduction-t-img:nth-child(2){
        margin-right: 0;
    }
    .about-introduction-b-r-box{
        display: none;
    }
    .about-introduction-b-l-box{
        width: 100%;
        margin: 0;
    }
    .about-introduction-b-l-img{
        height: calc(96vw * (360 / 724));
    }
    .about-introduction-b-l-text-box{
        padding-left: 0;
        height: 300px;
        display: block;
        height: inherit;
        margin-top: 15px;
    }
    .about-menu-box{
        width: 95%;
        display: block;
        margin: 0 auto;
    }
    .about-language-box{
        width: 324px;
        position: relative;
    }
    .rwd-about-language-now{
        width: 100%;
        height: 36px;
        border: 1px solid #555;
        font-size: 16px;
        letter-spacing: 1px;
        text-align: center;
        display: block;
        line-height: 36px;
        position: relative;
        box-sizing: border-box;
    }
    .rwd-about-language-now:after{
        content: '';
        width: 0px;
        height: 0px;
        margin: 0 auto;
        border-right: 5px solid transparent;
        border-top: 10px solid #555;
        border-left: 5px solid transparent;
        display: block;
        position: absolute;
        bottom: calc(50% - 5px);
        right: 5%;
        box-sizing: border-box;
    }
    .about-language-all-box{
        display: none;
        position: absolute;
        background-color: #fff;
        width: 100%;
        border: 1px solid #555;
        border-top: none;
        border-bottom: none;
        box-sizing: border-box;
        box-shadow: 0 5px 5px rgba(0, 0, 0, 0.6);
    }
    .about-language{
        display: block;
        margin: 0;
        width: 100%;
        box-sizing: border-box;
        padding: 5px 0;
    }
}
@media only screen and (max-width: 750px){
    .about-introduction-t-img{
        display: none;
    }
    .about-introduction-b-l-text-box,
    .about-introduction-t-aims{
        margin-top: 0;
    }
    .about-language{
        font-size: 16px;
    }
    .about-introduction-b-l-img{
        width: 100%;
        height: calc(95vw * (280 / 728));
    }
}
@media only screen and (max-width: 550px){
    .about-introduction-t-aims-title, 
    .about-introduction-b-l-text-title{
        font-size: 20px;
    }
    .about-btn-box{
        padding-top: 20px;
    }
    .about-box{
        margin-top: 58px;
    }
    .about-introduction-box{
        margin-top: 20px;
    }
    .about-language{
        font-size: 14px;
    }
}
@media only screen and (max-width: 400px){
    .about-language-box{
        width: 95vw;
    }
    .about-introduction-t-aims-title, 
    .about-introduction-b-l-text-title{
        font-size: 16px;
    }
    .about-introduction-t-aims-text,
    .about-introduction-b-l-text{
        font-size: 12px;
        line-height: 2;
    }
    .about-btn{
        width: 100px;
        font-size: 16px;
        line-height: 36px;
    }
}



/*animation*/
@media only screen and (min-width: 1001px){
    .about-btn-box,
    .about-introduction-t-img,
    .about-introduction-t-aims,
    .about-introduction-b-l-img,
    .about-introduction-b-r-box,
    .about-introduction-b-l-text-box,
    .about-menu-img,
    .about-menu-text-box,
    .about-menu-box,
    .about-image-box{
        opacity: 0;
    }
    .about-introduction-t-aims.anima,
    .about-btn-box{
        animation: fadeInDown 0.8s ease 0s 1 both;
    }
    .about-menu-img.anima{
        animation: fadeInLeft 1s ease 0s 1 both;
    }
    .about-introduction-b-l-img.anima,
    .about-introduction-b-l-text-box.anima,
    .about-menu-box.anima{
        animation: fadeInUp 0.8s ease 0s 1 both;
    }
    .about-introduction-t-img.anima,
    .about-language-box,
    .about-image-box.anima{
        animation: fade 1s ease 0s 1 both;
    }
    .about-introduction-b-r-box.anima,
    .about-menu-text-box.anima{
        animation: fadeInRight 1s ease 0s 1 both;
    }
}