body {
    margin: 0;
    padding: 0;
    font-family: Yu Gothic, sans-serif;
    font-size: 100%;
    background: #efefef;
}

aside {
    position: fixed;
    z-index: 10;
    top: 10px;
    right: 10px;
}

aside div {
    width: 30px;
    height: 3px;
    margin: 6px 0;
    background: olive;
}

nav {
    display: none;
    position: fixed;
    z-index: 100;
    top: 30px;
    right: 10px;
}

nav.show {
    display: block;
}

li {
    list-style: none;
}

li a {
    text-decoration: none;
    color: #333;
}

li a:hover {
    text-decoration: underline;
    text-decoration-skip: ink;
    color: olive;
}

h1 {
    text-align: center;
}

#intro div {
    display: flex;
    justify-content: center;
}

#intro article {
    border: 3px solid olive;
    border-radius: 6px;
    padding: .5rem 1rem;
    width: 25rem;
    height: auto;
    background: #fff;
}

#intro img {
    width: 200px;
    height: auto;
    display: block;
    margin: 0 auto;
    padding: 1rem;
}

#intro img:hover {
    opacity: .8;
}

#intro figcaption {
    text-align: center;

}

button {
    display: block;
    padding: 1rem 2rem;
    background: olive;
    outline: none;
    font-family: Yu Gothic, sans-serif;
    font-size: 150%;
    font-weight: 800;
    border: 1px #ddd solid;
    box-shadow: 4px 4px 0 0 #262626;
    border-radius: 8px;
    width: 21rem;
    height: 5rem;
    max-width: 90vw;
    margin: auto;
}

button a {
    color: #fff;
}

button:hover {
    background: orange;
    transition: .2s;
}

main {
    width: 85%;
    margin: 0 auto;
}

code {
    display: block;
    font-family: Consolas, monospace;
}

code span {
    display: inline-block;
    position: absolute;
    background: #222;
    color: #fff;
    padding: 3px 6px;
    z-index: 10;
}

textarea {
    background: #ddd;
    outline: 0;
    border: 0;
    width: 100%;
    font-size: 115%;
    padding: 2rem 2rem 1rem;
    font-family: Consolas, monospace;
    overflow: hidden;
}

textarea[id^="h"] {
    background: #8dd;
}

textarea[id^="c"] {
    background: #dd8;
}

label {
    position: absolute;
    right: 0;
    background: orange;
    padding: .5em;
    border-radius: 4px;
    font-family: Yu Gothic, sans-serif;
    font-weight: bold;
}

label:hover {
    background: olive;
}

#h1 {
    height: 9em;
}

#c1 {
    height: 8em;
}

#h2 {
    height: 9em;
}

#c2 {
    height: 19em;
}

#h3 {
    height: 17em;
}

#c3 {
    height: 21em;
}

#h4 {
    height: 10em;
}

#c4 {
    height: 22em;
}

#h5 {
    height: 32em;
}

#c5 {
    height: 27em;
}

#h6 {
    height: 7em;
}

#c6 {
    height: 43em;
}

#h7 {
    height: 20em;
}

#c7 {
    height: 33em;
}

#h8 {
    height: 7em;
}

#c8 {
    height: 7em;
}

#c9 {
    height: 13em;
}

main + div {
    position: fixed;
    right: 10px;
    bottom: 10px;
}

@media screen and (max-width: 777px) {
    #intro div {
        flex-direction: column;
        align-items: center;
    }

    #intro article {
        width: 80vw;
    }

    button {
        width: 70vw;
        height: 8rem;
    }

    textarea {
        white-space: pre-wrap;
        max-width: 80%;
        font-size: 8px;
    }
}