* {
    margin: 0px;
    padding: 0px;
}

a {
    text-decoration: none;
    color: #000;
}

header {
    display: flex;
    align-items: center;
    background-color: aquamarine;
    height:15vh;
    font-weight: 900;
    font-family: fangsong;
}

header img {
    height: 100px;
}

#content {
    display: flex;
    width: 100vw;
}

nav {
    display: inline-block;
    height: 85vh;
    width: calc(20vw - 1px);
}

nav a {
    display: block;
    font-family: kaiti;
    font-size: 1.5em;
    line-height: calc((85vh - 2px) / 6);
    text-align: center;
    height: calc((85vh - 2px) / 6);
    background-color: lightgreen;
    transition: background-color .2s linear;
    border-right: 1px solid #000;
}

nav a:hover {
    background-color: green;
    color: snow;
}

#main {
    display: inline-block;
    background-color: snow;
    align-self: stretch;
    height: 85vh;
    width: 80vw;
}

#main>h1 {
    text-align: center;
}