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

:root {
    --bg-primary: #0a0a0a;
    --bg-secondary: #121212;
    --bg-tertiary: #1a1a1a;
    --text-primary: #e8e8e8;
    --text-secondary: #a0a0a0;
    --text-muted: #666666;
    --border-color: #2a2a2a;
    --accent: #ffffff;
}

body {
    font-family: 'Crimson Text', 'Georgia', serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.7;
    font-size: 16px;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 2rem;
}

header {
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    padding: 3rem 0 2rem;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 400;
    letter-spacing: 0.05em;
    margin-bottom: 0.5rem;
}

header .tagline {
    color: var(--text-secondary);
    font-size: 1rem;
    font-weight: 300;
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

nav {
    background-color: var(--bg-tertiary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

nav ul {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    padding: 0;
    margin: 0;
}

nav li {
    margin: 0;
}

nav a {
    display: block;
    padding: 1rem 1.25rem;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    letter-spacing: 0.05em;
    transition: color 0.2s ease, background-color 0.2s ease;
}

nav a:hover {
    color: var(--accent);
    background-color: var(--bg-secondary);
}

main {
    padding: 6.5rem 2rem 4rem !important;
}

main.container {
    padding-top: 6.5rem !important;
}

section {
    margin-bottom: 5rem;
}

section:last-of-type {
    margin-bottom: 3rem;
}

h2 {
    font-size: 2rem;
    font-weight: 400;
    margin-bottom: 2rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-color);
    letter-spacing: 0.02em;
}

h3 {
    font-size: 1.4rem;
    font-weight: 400;
    margin-top: 2.5rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
    letter-spacing: 0.01em;
}

h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-secondary);
    letter-spacing: 0.02em;
    text-transform: uppercase;
    font-size: 0.95rem;
}

p {
    margin-bottom: 1.25rem;
    color: var(--text-primary);
}

ul {
    margin-bottom: 1.5rem;
    padding-left: 2rem;
}

li {
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

a {
    color: var(--text-primary);
    text-decoration: underline;
    text-decoration-color: var(--text-muted);
    transition: text-decoration-color 0.2s ease;
}

a:hover {
    text-decoration-color: var(--accent);
}

strong {
    font-weight: 600;
    color: var(--accent);
}

.subsystem-intro {
    font-style: italic;
    color: var(--text-secondary);
    margin-bottom: 3rem;
    padding: 1.5rem;
    background-color: var(--bg-secondary);
    border-left: 3px solid var(--border-color);
}

article.subsystem {
    margin-bottom: 3.5rem;
    padding: 2rem;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
}

article.subsystem h3 {
    margin-top: 0;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-color);
}

article.subsystem h4 {
    margin-top: 2rem;
}

article.subsystem h4:first-of-type {
    margin-top: 1.5rem;
}

.category-label {
    display: inline-block;
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    padding: 0.4rem 0.8rem;
    margin-bottom: 1.5rem;
    background-color: var(--bg-tertiary);
    border-left: 3px solid var(--text-muted);
    color: var(--text-secondary);
}

.category-a .category-label {
    border-left-color: #4a9eff;
    color: #4a9eff;
}

.category-b .category-label {
    border-left-color: #9b59b6;
    color: #9b59b6;
}

.category-c .category-label {
    border-left-color: var(--text-muted);
    color: var(--text-secondary);
}

footer {
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 2rem 0;
    margin-top: 4rem;
}

footer p {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
    text-align: center;
}

@media (max-width: 768px) {
    .container {
        padding: 0 1.5rem;
    }

    header {
        padding: 2rem 0 1.5rem;
    }

    header h1 {
        font-size: 2rem;
    }

    nav ul {
        flex-direction: column;
    }

    nav a {
        padding: 0.75rem 1rem;
        border-bottom: 1px solid var(--border-color);
    }

    main {
        padding: 2rem 1.5rem;
    }

    h2 {
        font-size: 1.6rem;
    }

    h3 {
        font-size: 1.25rem;
    }

    article.subsystem {
        padding: 1.5rem;
    }
}

@media (max-width: 480px) {
    body {
        font-size: 15px;
    }

    header h1 {
        font-size: 1.75rem;
    }

    header .tagline {
        font-size: 0.85rem;
    }

    h2 {
        font-size: 1.4rem;
    }

    h3 {
        font-size: 1.15rem;
    }
}