nav {
    position: fixed;
    top: 50px;
    width: 100%;
    z-index: 10;
}

ul {
    height: 0;
    overflow: hidden;
    transition: .3s;
    list-style: none;
}

li a {
    padding: 4px;
    margin-left: 4px;
    font-size: 16px;
    color: #464646;
    display: block;
    text-decoration: none;
    text-align: left;
}

.hamburger {
    position: absolute;
    top: 0px;
    left: 10px;
    cursor: pointer;
    width: 32px;
    height: 24px;
    z-index: 10;
}

.hamburger span {
    /*3本の線を作る*/
    transition: all .3s;
    position: absolute;
    height: 2px;
    background-color: #333;
    width: 100%;
    z-index: 10;
    left: 0px;
}

.hamburger span:nth-of-type(1) {
    /*上の線の位置*/
    top: -3.5px;
}

.hamburger span:nth-of-type(2) {
    /*真ん中の線の位置*/
    top: 8.25px;
    height:1.5px;
}

.hamburger span:nth-of-type(3) {
    /*下の線の位置*/
    top: 19px;
}

.hamburger.open span:nth-of-type(1) {
    /*openのとき、上の線を右斜めにする*/
    top: -3.5px;
    transform: translateY(11.5px) rotate(-45deg);
}

.hamburger.open span:nth-of-type(2) {
    /*真ん中の線を消す*/
    opacity: 0;
}

.hamburger.open span:nth-of-type(3) {
    /*下の線を左斜めにする*/
    top: 19px;
    transform: translateY(-11.5px) rotate(45deg);
}

nav .open {
    margin-left: 0.5rem;
    margin-right:0.5rem;
    border:1px solid black;
}

#header-menu {
    position: fixed;
    background-color: white;
    width: 120px;
    border-radius: 8px;
    margin-left: 0.5rem;
    margin-right: 0.5rem;
}

ul {
    padding-inline-start: 0px;
}

.header-menu-menu {
    font-size: 140%;
    color: #46c985;
    border-bottom: 1px solid black;
}

.header-div1 {
    position: fixed;
    left: 0px;
    top: 4px;
}

.hamburger-div1 {
    position: absolute;
    width: 16px;
    height: 13.333333333333333px;
    padding: 10px;
    border: 1px solid black;
    background-color: white;
    border-radius: 6px;
}

.hamburger-div2 {
    position: absolute;
    width: 80%;
    height: 100%;
    top: 8px;
    left: 10%;
}