:root {
    --bg-color: #f4f4f4;
    --text-color: #333;
    --header-footer-bg: #333;
    --header-footer-text: white;
    --section-bg: white;
    --section-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    --link-color: #3498db;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #222;
        --text-color: #eee;
        --header-footer-bg: #111;
        --header-footer-text: #ddd;
        --section-bg: #333;
        --section-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
        --link-color: #4dabf7;
    }
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: Arial, Helvetica, sans-serif;
    line-height: 1.8;
    color: var(--text-color);
    background-color: var(--bg-color);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    padding-top: 60px;
}

header {
    background-color: var(--header-footer-bg);
    color: var(--header-footer-text);
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    height: 60px;
}

.hamburger {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    width: 30px;
    height: 21px;
    padding: 0;
    position: relative;
    z-index: 1001;
}

.hamburger-line {
    display: block;
    position: absolute;
    height: 3px;
    width: 100%;
    background: var(--header-footer-text);
    border-radius: 2px;
    opacity: 1;
    left: 0;
    transform: rotate(0deg);
    transition: 0.25s ease-in-out;
}

.hamburger-line:nth-child(1) { top: 0; }
.hamburger-line:nth-child(2) { top: 9px; }
.hamburger-line:nth-child(3) { top: 18px; }

.hamburger.active .hamburger-line:nth-child(1) {
    transform: rotate(-45deg) translate(-5px, 6px);
}
.hamburger.active .hamburger-line:nth-child(2) { opacity: 0; }
.hamburger.active .hamburger-line:nth-child(3) {
    transform: rotate(45deg) translate(-5px, -6px);
}

nav ul {
    display: flex;
    list-style: none;
    gap: 1rem;
}

nav a {
    color: var(--header-footer-text);
    text-decoration: none;
    padding: 0.5rem 1rem;
}

nav a:hover {
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 4px;
}

main {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 2rem;
}

h1 {
    margin-block: 0.67em;
    font-size: 2em;
}

h2 {
    margin-block: 0.85em;
}

section {
    max-width: 1200px;
    width: 100%;
    padding: 2rem;
    margin-bottom: 2rem;
    background-color: var(--section-bg);
    border-radius: 8px;
    box-shadow: var(--section-shadow);
    text-align: left;
}

section a {
    color: var(--link-color);
}

footer {
    background-color: var(--header-footer-bg);
    color: var(--header-footer-text);
    text-align: center;
    padding: 1rem;
}

@media (max-width: 768px) {
    .hamburger {
        display: block;
    }

    nav ul {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 60px;
        left: 0;
        width: 100%;
        background-color: var(--header-footer-bg);
        padding: 1rem;
        gap: 0;
    }

    nav ul.show {
        display: flex;
    }

    nav a {
        display: block;
        padding: 0.75rem;
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    }
}