:root {
    --color-bg: #f0f2f5;
    --color-card-bg: #ffffff;
    --color-card-shadow: rgba(0, 0, 0, 0.1);
    --color-text: #111;
    --color-text-secondary: #333;
}

@media (prefers-color-scheme: dark) {
    :root {
        --color-bg: #121212;
        --color-card-bg: #1e1e1e;
        --color-card-shadow: rgba(0, 0, 0, 0.5);
        --color-text: #eee;
        --color-text-secondary: #ccc;
    }
}

body {
    background: var(--color-bg);
    font-family: system-ui, -apple-system, sans-serif;
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

nav {
    background: var(--color-card-bg);
    box-shadow: 2px 0 8px rgba(0, 0, 0, 0.1);
    padding: 0.75rem;
    display: flex;
    flex-direction: row;
    gap: 1rem;
    box-sizing: border-box;
    z-index: 1000;
}

nav a {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--color-text);
    text-decoration: none;
    font-weight: 500;
    font-size: 1rem;
    transition: color 0.3s ease, transform 0.2s ease;
}

nav a svg {
    width: 24px;
    height: 24px;
    fill: var(--color-text);
    transition: transform 0.3s ease, fill 0.3s ease;
}

nav a:hover {
    color: var(--color-text-secondary);
}

nav a:hover svg {
    transform: scale(1.2);
    fill: var(--color-text-secondary);
}

@media (max-width: 768px) {
    nav {
        width: 60px;
        padding: 1rem 0.5rem;
    }

    nav a span {
        display: none;
    }

    nav a {
        justify-content: center;
        flex-direction: column;
    }
}

main {
    margin-left: 0;
    transition: margin-left 0.3s ease;
}

@media (min-width: 768px) {
    main {
        margin-left: 220px;
    }
}

main {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1rem;
    box-sizing: border-box;
}

@media (min-width: 768px) {
    main {
        grid-template-columns: repeat(2, 1fr);
    }
}

body {
    counter-reset: section;
}

section {
    counter-increment: section;
    background: var(--color-card-bg);
    border-radius: 1rem;
    padding: 1.5rem;
    box-shadow: 0 4px 12px var(--color-card-shadow);
    opacity: 1;
}

section h2 {
    margin-top: 0;
    font-size: 1.5rem;
    color: var(--color-text);
}

section p {
    margin-bottom: 0;
    line-height: 1.6;
    font-size: 1rem;
    color: var(--color-text-secondary);
}