:root {
    --color-bg: #0a0a0a;
    --color-text: #f5f5f5;
    --color-accent: #B4121B;
    --color-muted: #999999;
    --color-border: #2a2a2a;
    --color-card: #141414;
    --color-accent-light: #d41f29;
    --color-accent-dark: #8f0e15;
    --font-serif: 'Crimson Pro', serif;
    --font-mono: 'IBM Plex Mono', monospace;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: var(--font-serif);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.7;
    overflow-x: hidden;
}

/* Navigation */
nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(10, 10, 10, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
    z-index: 1000;
    animation: slideDown 0.6s ease-out;
}

@keyframes slideDown {
    from {
        transform: translateY(-100%);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1.5rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    font-family: var(--font-mono);
    font-weight: 600;
    font-size: 1rem;
    color: var(--color-text);
    text-decoration: none;
    letter-spacing: -0.02em;
}

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.nav-links a {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--color-muted);
    text-decoration: none;
    transition: var(--transition);
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-accent);
    transition: var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--color-accent);
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

/* Page Header */
.page-header {
    margin-top: 80px;
    padding: 4rem 2rem 3rem;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
    border-bottom: 1px solid var(--color-border);
    animation: fadeIn 0.8s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.breadcrumb {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--color-muted);
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.breadcrumb a {
    color: var(--color-muted);
    text-decoration: none;
    transition: var(--transition);
}

.breadcrumb a:hover {
    color: var(--color-accent);
}

.page-title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
}

.page-subtitle {
    font-size: 1.25rem;
    color: var(--color-muted);
    max-width: 700px;
}

/* Main Content */
.main-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem;
}

.content-wrapper {
    max-width: 800px;
}

.main-content h2 {
    font-size: 2rem;
    font-weight: 600;
    margin-top: 3rem;
    margin-bottom: 1.5rem;
    letter-spacing: -0.01em;
}

.main-content h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-top: 2.5rem;
    margin-bottom: 1rem;
}

.main-content p {
    font-size: 1.125rem;
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.main-content ul,
.main-content ol {
    margin-bottom: 1.5rem;
    padding-left: 2rem;
}

.main-content li {
    font-size: 1.125rem;
    margin-bottom: 0.75rem;
    line-height: 1.7;
}

.main-content a {
    color: var(--color-accent);
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: var(--transition);
}

.main-content a:hover {
    border-bottom-color: var(--color-accent);
}

.main-content blockquote {
    border-left: 4px solid var(--color-accent);
    padding-left: 1.5rem;
    margin: 2rem 0;
    font-style: italic;
    color: var(--color-muted);
}

.main-content code {
    font-family: var(--font-mono);
    font-size: 0.9em;
    background: var(--color-card);
    border: 1px solid var(--color-border);
    padding: 0.2em 0.4em;
    border-radius: 3px;
}

.main-content pre {
    background: var(--color-card);
    border: 1px solid var(--color-border);
    padding: 1.5rem;
    border-radius: 4px;
    overflow-x: auto;
    margin: 2rem 0;
}

.main-content pre code {
    background: none;
    border: none;
    padding: 0;
}

/* Cards */
.card {
    background: var(--color-card);
    border: 1px solid var(--color-border);
    padding: 2rem;
    margin-bottom: 2rem;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 0;
    background: var(--color-accent);
    transition: var(--transition);
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 16px rgba(180, 18, 27, 0.12);
    border-color: var(--color-accent);
}

.card:hover::before {
    height: 100%;
}

.card-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.card-meta {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--color-muted);
    margin-bottom: 1rem;
}

.card-description {
    color: var(--color-muted);
    margin-bottom: 1rem;
}

.card-link {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--color-accent);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
}

.card-link:hover {
    gap: 1rem;
}

/* Course Items (Classes page) */
.course-item {
    background: var(--color-card);
    border: 1px solid var(--color-border);
    border-left: 4px solid var(--color-accent);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    transition: var(--transition);
}

.course-item:hover {
    transform: translateX(4px);
    box-shadow: 0 4px 12px rgba(180, 18, 27, 0.15);
}

.course-year {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--color-accent);
    margin-bottom: 0.5rem;
}

.course-title {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--color-text);
}

.course-institution {
    font-size: 1rem;
    color: var(--color-muted);
}

/* Book Cards (Publications page) */
.book-card {
    background: var(--color-card);
    border: 1px solid var(--color-border);
    border-left: 4px solid var(--color-accent);
    padding: 2rem;
    margin-bottom: 2rem;
    transition: var(--transition);
    display: flex;
    gap: 2rem;
    align-items: flex-start;
}

.book-card:hover {
    transform: translateX(4px);
    box-shadow: 0 8px 16px rgba(180, 18, 27, 0.2);
}

.book-cover {
    flex-shrink: 0;
    width: 150px;
    height: auto;
    border: 1px solid var(--color-border);
}

.book-info {
    flex: 1;
}

.book-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--color-text);
    line-height: 1.4;
}

.book-meta {
    font-size: 1rem;
    color: var(--color-muted);
    margin-bottom: 1rem;
}

.book-links {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-top: 1rem;
}

.book-link {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--color-accent);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
    border-bottom: 1px solid transparent;
}

.book-link:hover {
    border-bottom-color: var(--color-accent);
}

/* Article Items (Publications page) */
.article-item {
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--color-border);
}

.article-item:last-child {
    border-bottom: none;
}

.article-title {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--color-text);
    line-height: 1.5;
}

.article-meta {
    font-size: 1rem;
    color: var(--color-muted);
    line-height: 1.6;
}

/* Construction Page */
.main-container {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
}

.construction-box {
    text-align: center;
    max-width: 600px;
}

.construction-icon {
    font-size: 4rem;
    margin-bottom: 2rem;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.subtitle {
    font-size: 1.25rem;
    color: var(--color-muted);
    margin-bottom: 2rem;
}

.message {
    font-size: 1.125rem;
    color: var(--color-text);
    line-height: 1.8;
    margin-bottom: 2rem;
}

.back-link {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--color-accent);
    text-decoration: none;
    padding: 0.75rem 1.5rem;
    border: 2px solid var(--color-accent);
    border-radius: 4px;
    transition: var(--transition);
}

.back-link:hover {
    background: var(--color-accent);
    color: var(--color-bg);
    transform: translateY(-2px);
}

/* Footer */
footer {
    border-top: 1px solid var(--color-border);
    padding: 3rem 2rem;
    text-align: center;
    color: var(--color-muted);
    font-family: var(--font-mono);
    font-size: 0.85rem;
}

footer a {
    color: var(--color-muted);
    text-decoration: none;
    transition: var(--transition);
}

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

/* Mobile Menu */
.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
    background: none;
    border: none;
    padding: 0.5rem;
}

.menu-toggle span {
    width: 24px;
    height: 2px;
    background: var(--color-text);
    transition: var(--transition);
}

/* Responsive */
@media (max-width: 768px) {
    .menu-toggle {
        display: flex;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--color-bg);
        border-top: 1px solid var(--color-border);
        flex-direction: column;
        padding: 1rem 2rem;
        gap: 1rem;
    }

    .nav-links.active {
        display: flex;
    }

    .page-header {
        padding: 3rem 1.5rem 2rem;
    }

    .main-content {
        padding: 2rem 1.5rem;
    }

    .main-content h2 {
        font-size: 1.75rem;
    }

    .main-content h3 {
        font-size: 1.25rem;
    }

    .main-content p,
    .main-content li {
        font-size: 1rem;
    }

    .book-card {
        flex-direction: column;
    }

    .book-cover {
        width: 100%;
        max-width: 200px;
    }

    .construction-icon {
        font-size: 3rem;
    }
}