:root {
    --background-color: #222;
    --text-color: #fff;
    --nav-color: #333;
    --active-color: #888;
    --font: 'EB Garamond', Arial;
    --shadow-weak: 0 2px 30px rgba(0, 0, 0, 0.3);
    --shadow-strong: 0 2px 30px rgba(0, 0, 0, 0.6);
}

:root.light {
    --background-color: #fff;
    --text-color: #121212;
    --nav-color: #fff;
    --active-color: #aaa;
    --shadow-weak: 0 2px 30px rgba(0, 0, 0, 0.2);
    --shadow-strong: 0 2px 30px rgba(0, 0, 0, 0.3);
}

:root.arial {
    --font: Arial;
}

* {
    transition: color 0.5s ease, background-color 0.5s ease;
    font-family: var(--font);
}

main {
    margin-bottom: 120px
}
 
body {
    color: var(--text-color);
    background-color: var(--background-color);
    font-size: 16px;
    margin: 0;
    padding: 1rem;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 0.5rem;
}

header nav a {
    display: inline-block;
    color: var(--text-color);
    text-decoration: none;
}

header .logo {
    max-width: 100%;
    height: auto;
    max-height: 60px;
}

.page {
    display: none;
}

.page.active {
    display: block;
}

.nav {
    background-color: color-mix(in srgb, var(--nav-color) 50%, transparent);
    backdrop-filter: blur(1px);
    -webkit-backdrop-filter: blur(1px);
    box-shadow: var(--shadow-strong);
    border: 1.5px solid rgba(255, 255, 255, 0.2);
    border-radius: 20px;
    position: fixed;
    display: flex;
    justify-content: space-around;
    align-items: center;
    bottom: 0;
    left: 0;
    right: 0;
    height: 80px;
    z-index: 1000;
    margin-left: 10px;
    margin-right: 10px;
    margin-bottom: 15px;
}

#button {
    background: none;
    border: none;
    padding: 0.75rem;
    color: var(--text-color);
}

#button span {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: var(--text-color);
    text-decoration: none;
    font-size: 0.8rem;
    flex: 1;
}

#button i {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

h1 {
    font-size: 2em;
    text-align: center;
}

.flex-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

details {
    border: 1.5px var(--text-color);
    border-radius: 10px;
    background: var(--nav-color);
    padding: 0.5rem;
    margin: 1rem;
    align-items: center;
    box-shadow: var(--shadow-weak)
}

details[open] {
    box-shadow: var(--shadow-strong)
}

details summary {
    list-style: none;
    cursor: pointer;
    font-size: 1.5em;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.5rem;
    text-align: center;
    position: relative;
}