@media (prefers-color-scheme: light) {
    :root {
        --foreground: black;
        --background: white;
        --accent1: #007f7f;
        --accent2: #7f7fff;
        --accent3: #e0e0e0;
        --accent4: #808080;
    }
}

@media (prefers-color-scheme: dark) {
    :root {
        --foreground: white;
        --background: black;
        --accent1: #7f7fff;
        --accent2: #007f7f;
        --accent3: #404040;
        --accent4: #808080;
    }
}

* {
    margin: 0;
    padding: 0;
    font-family: monospace;
}

body {
    display: flex;

    flex-direction: column;
    color: var(--foreground);
    background-color: var(--background);
}

button {
    display: flex;
    color: var(--foreground);
    background-color: var(--background);
    border: 1px solid #ddd;
    border-radius: 4px;
    padding: 10px 20px;
    font-size: 16px;
    cursor: pointer;
    align-items: center;
    gap: 10px;
}

main {

    display: flex;
    flex-direction: column;
    align-items: center;
    margin: 3rem;

    h1 {
        margin-bottom: 2rem;
        a {
            color: blue;
            text-decoration: none;
        }
    }

    h1, h2 {
        margin-bottom: 1rem;
    }

    article {
        max-width: 75vw;
        p {
            margin-bottom: 1rem;
        }
        ol {
            margin-left: 2rem;
            margin-bottom: 2rem;
            padding-left: 1rem;
            list-style-type: none;
            border-left: 1px solid gray;
            li{
                a{
                    text-decoration: none;
                    color: blue;
                }
            }
        }
        blockquote {
            border-left: 4px solid var(--accent4);
            padding-left: 1rem;
            margin-left: 3rem;
            color: var(--accent4);
            margin-bottom: 1rem;
        }
        figcaption {
            margin-left: 3rem;
            margin-bottom: 1rem;
            text-align: center;
        }
        code {
            display: block;
            margin-bottom: 1rem;
        }
        section {
            display: flex;
            flex-direction: column;
            align-items: center;
            margin-left: 2rem;
            margin-bottom: 2rem;
            img{
                margin-bottom: 1rem;
                max-width: 70vw;
            }
            ul {
                margin-left: 2rem;
                margin-bottom: 1rem;
            }
        }
    }
}

header {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: 1rem;
}

body nav {
    display: flex;
    justify-content: space-between;

    ul.nav {
        flex-wrap: wrap;
        li a {
            color: blue;
            text-decoration: none;
        }
    }

    div.user {
        display: flex;
        flex-direction: column;
        justify-content: space-between;
        border-left: 3px solid var(--background);
        font-size: 1.5rem;
        padding: 0rem 1rem;
        justify-content: center;
        text-align: center;
        white-space: nowrap;
        color: var(--foreground);
        background-color: var(--accent2);
        &.sign_in {
            color: var(--background);
            background-color: var(--foreground);
        }
    }
    
    &.l1{
        color: var(--background);
        background-color: var(--foreground);
    }

    &.l2{
        color: var(--foreground);
        background-color: var(--background);
    }
}

body nav ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
  overflow: hidden;
  display: inline-flex;
  align-items: center;
}

hr { 
    border: 1px solid var(--foreground);
}

body nav ul li {
  img {
    display: block;
    height: 2rem;
    width: 2rem;
  }
  &.selected {
    color: black;
  }
  display: block;
  text-align: center;
  padding: 0.5rem 1rem;
  white-space: nowrap;
  text-decoration: none;
  font-weight: bolder;
  font-size: 1.5rem;
}