body{
    font-weight: 400;
}
main{
    padding: 50px;
}
main h1{
    font-weight: 400;
    text-align: center;
}
nav{
    display: none;
    width: 220px;
    position: fixed;
    background-color: #ffffff;
    top: 0;
    left: -300;
    bottom: 0;
    transition: all 0.5s allow-discrete;
    z-index: 3;
    opacity: 0;
}
.open nav{
    display: block;
    left: 0;
    opacity: 1;
}
nav .inner{
    padding: 25px;
}
nav .inner ul{
    list-style: none;
    margin: 0;
    padding: 0;

}
nav .inner ul li{
    margin: 0;
    border-bottom: 1px solid #333333;
}
nav .inner ul li a{
    display: block;
    text-decoration: none;
    color: #333333;
    font-size: 14px;
    margin: 1rem;
    transition-duration: 0.2s;
}
nav .inner ul li a:hover{
    background-color: #e4e4c4;
}

div#navIcon{
    text-align: center;
    font-size: 12px;
}

.toggle-btn{
    display: block;
    position: fixed;
    top: 30px;
    right: 30px;
    width: 30px;
    height: 30px;
    z-index: 3;
    cursor: pointer;
}
.toggle-btn span{
    position: absolute;
    display: block;
    left: 0;
    width: 30px;
    height: 2px;
    background-color: #333333;
    transition: all 0.5s;
    border-radius: 4px;
}
.toggle-btn span:nth-child(1){
    top: 4px;
}
.toggle-btn span:nth-child(2){
    top: 14px;
}
.toggle-btn span:nth-child(3){
    bottom: 4px;
}
.open .toggle-btn span{
    background-color: #ffffff;
}
.open .toggle-btn span:nth-child(1){
    transform: translateY(10px) rotate(-315deg);
}
.open .toggle-btn span:nth-child(2){
    opacity: 0;
}
.open .toggle-btn span:nth-child(3){
    transform: translateY(-10px) rotate(315deg);
}
#mask{
    display: none;
    transition: all 0.5s;
}
.open #mask{
    display: block;
    background-color: #000000;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    position: fixed;
    opacity: 0.5;
    cursor: pointer;
}