#opening_box{
    position: fixed;
    left: 50%;
    top: 50%;
    translate: -50% -50%;
    background-color: black;
    width: 100%;
    height: 100%;
    z-index: 1000;
    opacity: 1;
}
#opening_box.open{
    opacity: 1;
}
#opening_box.close{
    animation: fade-out 1s forwards;
}
#background.none{
    display: none;
    width: 0%;
    height: 0%;
}
#background{
    position: absolute;
    left: 50%;
    top: 50%;
    translate: -50% -50%;
    width: 100%;
    height: 100%;
    opacity: 0.3;
    z-index: 1001;
}
.back_title_box{
    position: relative;
    width: 100%;
    height: 600px;
    overflow: hidden;
}
#waten_txt{
    writing-mode: vertical-rl;
    position: absolute;
    height: 100%;
    left: 50%;
    top: 60%;
    translate: -50% -50%;
    font-family: "しょかきさらり";
    font-size: 145px;/*1100px超えたら165px*/
    color: white;
    z-index: 1005;
    margin: 0;
    text-shadow: -5px 5px 3px #BA422B,5px 5px 2px#363A75;
}
#waten_txt.open{
    animation: fade-in 2s forwards;
}
#waten_txt.close{
    opacity: 0;
}
#kingyo{
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0%;
    left: 50%;
    translate: -50% 0;
}
#kingyo.none{
    display: none;
    width: 0%;
    height: 0%;
}
#kingyo.close{
    height: 0;
    overflow: hidden;
}
#kingyo.open{
    animation: wipe-in-height 2.1s forwards;
}
.kimg{
    position: absolute;
    left: 50%;
    top: 0;
    translate: -50% 0;
    aspect-ratio: 13/10;
    height: 600px;
}
.checkbox{
    width: 20px;
    height: 20px;
    position: absolute;
    left: 50%;
    top: 50%;
    /*
    background-color: red;
    */
}

@media  screen and (min-width: 1500px) and (min-height: 900px) {
    #waten_txt{
        font-size: 240px;
    }
    .back_title_box{
        height: 900px;
    }
    .kimg{
        height: 900px;
    }
    .checkbox{
        /*
        background-color: green;
        */
    }
}

@media screen and (min-width: 1100px) and (max-width: 1500px){
    #waten_txt{
        font-size: 165px;
    }
    .back_title_box{
        height: 700px;
    }
    .kimg{
        height: 700px;
    }
    .checkbox{
        /*
        background-color: blue;
        */
    }
}

@keyframes fade-in {
    0%{
        display: block;
        opacity: 0;
    }
    100%{
        opacity: 1;
    }
}
@keyframes fade-out {
    0%{
        opacity: 1;
    }
    99.999999999%{
        opacity: 0;
        width: 100%;
        height: 100%;
    }
    100%{
        display: none;
        width: 0%;
        height: 0%;
    }
}

@keyframes wipe-in-height {
    0%{
        overflow: hidden;
        height: 0%;
    }
    50%{
        height: 100%;
    }
    100%{
        height: 100%;
    }
}