html {
    height: 100%;
    padding: 0;
    margin: 0;
}

body {
    min-height: 100%;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
}

main {
    /* padding: 2rem; */
    display: flex;
    flex-direction: column;
    align-items: center;
    flex-grow: 1;
    box-sizing: border-box;
}

footer {
    /* position: absolute;
    bottom: 0;
    left: 0;
    right: 0; */
    border-top: 1px solid #ddd;
    background-color: #f5f5f5;
    font-size: 0.8rem;
    padding: 0.75rem 1.5rem;
    margin: 0;
    color: #222;
}

.footer ul {
    padding: 0;
    margin: 0;
    display: flex;
    gap: 1rem;
    flex-direction: row;
    justify-content: center;
}

.footer li {
    list-style: none;
    padding: 0;
    margin: 0;
}

h1, h2 {
    font-size: 2rem;
    margin-top: 0;
}

.container {
    padding: 1rem;
    width: 100%;
    box-sizing: border-box;
}

.grid {
    width: 100%;
    flex-grow: 1;
    display: grid;
    grid-template-columns: repeat(auto-fill, 50%);
}

.grid > * {
    padding: 2rem;
    border: 1px solid #ddd;
}

.link-card {
    display: block;
    text-decoration: none;
    color: inherit;
}

.link-card:hover {
    background-color: #f9f9f9;
}

.title, .subtitle {
    text-align: center;
}

.top-nav ul {
    padding: 1rem 1.25rem;
    margin: 0;
    display: flex;
    gap: 2rem;
}

.top-nav li {
    list-style: none;
    padding: 0;
    margin: 0;
}

.top-nav a {
    text-decoration: underline;
    color: #666;
}

.top-nav a:hover {
    color: #222;
}

@media (max-width: 600px) {
    .top-nav ul {
        justify-content: center;
        flex-wrap: wrap;
    }

    .grid {
        grid-template-columns: 1fr;
    }

    .title, .subtitle {
        text-align: left;
    }
}

/* dark mode */
@media (prefers-color-scheme: dark) {
    body {
        background-color: #222;
        color: #f5f5f5;
    }

    footer {
        border-top-color: #555;
        background-color: #333;
        color: #eee;
    }

    .footer a {
        color: #8af;
    }

    .footer a:hover {
        color: #acf;
    }

    .grid > * {
        border-color: #555;
    }

    .link-card:hover {
        background-color: #333;
    }

    .top-nav a {
        color: #8af;
    }

    .top-nav a:hover {
        color: #acf;
    }
}