:root {
    --primary-color: #3b82f6;
    --text-color: #1f2937;
    --bg-color: #ffffff;
    --section-bg: #f9fafb;
}

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

body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

header {
    background: var(--primary-color);
    color: white;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

header h1 {
    font-size: 1.5rem;
}

nav a {
    color: white;
    text-decoration: none;
    margin-left: 1.5rem;
    opacity: 0.9;
    transition: opacity 0.2s;
}

nav a:hover {
    opacity: 1;
}

main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

section {
    padding: 3rem 0;
    border-bottom: 1px solid #e5e7eb;
}

section:last-child {
    border-bottom: none;
}

#hero {
    text-align: center;
    padding: 4rem 0;
}

#hero h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

#hero p {
    font-size: 1.25rem;
    color: #6b7280;
}

h2 {
    margin-bottom: 1rem;
    color: var(--primary-color);
}

ul {
    list-style-position: inside;
}

li {
    margin: 0.5rem 0;
}

footer {
    background: var(--section-bg);
    text-align: center;
    padding: 2rem;
    color: #6b7280;
}

a {
    color: var(--primary-color);
}

@media (max-width: 768px) {
    header {
        flex-direction: column;
        gap: 1rem;
    }

    nav a {
        margin: 0 0.75rem;
    }

    #hero h2 {
        font-size: 2rem;
    }
}

@media (prefers-color-scheme: dark) {
    :root {
        --text-color: #f9fafb;
        --bg-color: #111827;
        --section-bg: #1f2937;
    }

    header {
        background: #1e40af;
    }

    section {
        border-color: #374151;
    }
}