nav{
    display: block;
    width: 220px;
    position: fixed;
    background-color: #ffffff;
    top: 0;
    left: -300px;;
    bottom: 0;
    transition: all 0.5s;
    z-index: 3;
    opacity: 0;
}

.open nav{
    left: 0;
    opacity: 1;
    z-index: 4;
}

nav .inner{
    padding: 25px;
}

nav .inner ul{
    list-style: none;
    margin: 0;
    padding: 0;
}

nav .inner ul li{
    margin: 0;
    border-bottom: 1px solid #333;
}

nav .inner ul li a{
    display: block;
    text-decoration: none;
    color: #333;
    font-size: 14px;
    padding: 1rem;
    transition-duration: 0.2s;
}

nav .inner ul li a:hover{
    background-color: #e4e4e4;
}

.toggle-button{
    display: block;
    position: fixed;
    top: 3%;
    right: 30px;
    width: 30px;
    height: 30px;
    z-index: 3;
    cursor: pointer;
}

.toggle-button span{
    position: absolute;
    display: block;
    left: 0;
    width: 30px;
    height: 2px;
    background-color: #333;
    transition: all 0.5s;
    border-radius: 4px;
}

.toggle-button span:nth-child(1){
    top: 4px;
}

.toggle-button span:nth-child(2){
    top: 14px;
}

.toggle-button span:nth-child(3){
    bottom: 4px;
}

.open .toggle-button{
    z-index: 4;
}

.open .toggle-button span{
    background-color: #ffffff;
}

.open .toggle-button span:nth-child(1){
    transform: translateY(10px) rotate(-315deg);
}

.open .toggle-button span:nth-child(2){
    opacity: 0;    
}

.open .toggle-button span:nth-child(3){
    transform: translateY(-10px) rotate(315deg);
}

#mask{
    display: none;
    transition: all 0.5s;
}

.open #mask{
    display: block;
    background-color: #000;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    position: fixed;
    opacity: 0.8;
    cursor: pointer;
    z-index: 3;
}

h1{
    color: #000!important;
    font-family: "HG正楷書体-PRO";
    font-size: 30px!important;
}

h1 span{
    font-size: 40px!important;
}

header a{
    text-decoration: none;
}

header{
    position: fixed;
    top: 0%;
    left: 0;
    width: 100%;
    justify-content: space-between;
    padding: 0.3%;
    padding-left: 3%;
    background-color: #ffffff;
    border-bottom: 1px solid #c8c8c8;
    z-index: 2;
}

#kamon{
    width: 57px;
    height: 57px;
    margin-top: 0.7%;
    margin-right: 0.5%;
}

#flexbox {
    display: flex;
}


@media screen and (max-width: 750px){
    h1{
        font-size: 15px!important;
    }

    h1 span{
        font-size: 30px!important;
    }

    .toggle-button{
        top: 1.5%;
    }

    #kamon{
        width: 35px;
        height: 35px;
        margin-top: 2%;
        margin-left: 2%;
        margin-right: 2%;
    }
}