/* ===================================
   CSS Variables & Design Tokens
   =================================== */
:root {
    /* Colors - Inspired by architectural heritage */
    --primary-color: #2c3e50;
    --secondary-color: #8b7355;
    --accent-color: #c9a87c;
    --text-primary: #1a1a1a;
    --text-secondary: #666;
    --text-light: #999;
    --background: #fafaf8;
    --white: #ffffff;
    --border-color: #e5e5e5;

    /* Typography */
    --font-serif: 'Cormorant Garamond', serif;
    --font-sans: 'Inter', sans-serif;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-medium: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* ===================================
   Global Styles
   =================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

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

h1,
h2,
h3,
h4,
h5,
h6 {
    font-family: var(--font-serif);
    font-weight: 400;
    line-height: 1.3;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

img {
    max-width: 100%;
    height: auto;
    display: block;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.section {
    padding: var(--spacing-xl) 0;
}

.section-title {
    font-size: 3rem;
    font-weight: 300;
    margin-bottom: var(--spacing-lg);
    text-align: center;
    color: var(--primary-color);
    letter-spacing: 0.02em;
}

.section-intro {
    font-size: 1.125rem;
    color: var(--text-secondary);
    text-align: center;
    max-width: 700px;
    margin: 0 auto var(--spacing-lg);
    line-height: 1.8;
}

/* Hidden class for language switching */
.hidden {
    display: none !important;
}

/* ===================================
   Language Switcher
   =================================== */
.language-switcher {
    position: fixed;
    top: var(--spacing-md);
    right: var(--spacing-md);
    z-index: 1000;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(255, 255, 255, 0.95);
    padding: 0.5rem 1rem;
    border-radius: 50px;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.08);
    backdrop-filter: blur(10px);
}

.lang-btn {
    background: transparent;
    border: none;
    font-family: var(--font-sans);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.25rem 0.5rem;
    transition: color var(--transition-fast);
    letter-spacing: 0.05em;
}

.lang-btn:hover {
    color: var(--primary-color);
}

.lang-btn.active {
    color: var(--primary-color);
    font-weight: 600;
}

.separator {
    color: var(--border-color);
    font-size: 0.9rem;
}

/* ===================================
   Navigation
   =================================== */
.main-nav {
    background: var(--white);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 999;
    backdrop-filter: blur(10px);
    background: rgba(255, 255, 255, 0.98);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-md);
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
}

.nav-link {
    font-family: var(--font-sans);
    font-size: 0.95rem;
    font-weight: 400;
    color: var(--text-primary);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    position: relative;
    padding-bottom: 0.25rem;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--secondary-color);
    transition: width var(--transition-medium);
}

.nav-link:hover::after {
    width: 100%;
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    align-items: center;
    min-height: 80vh;
    padding: var(--spacing-xl) var(--spacing-md);
    max-width: 1200px;
    margin: 0 auto;
}

.hero-content {
    padding-right: var(--spacing-md);
}

.hero-title {
    font-size: 4rem;
    font-weight: 300;
    margin-bottom: var(--spacing-sm);
    color: var(--primary-color);
    line-height: 1.1;
}

.hero-subtitle {
    font-family: var(--font-sans);
    font-size: 1.25rem;
    color: var(--secondary-color);
    font-weight: 300;
    letter-spacing: 0.05em;
}

.hero-image-placeholder {
    width: 100%;
    height: 600px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-image-placeholder img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* ===================================
   About Section
   =================================== */
.about-section {
    background: var(--white);
}

.about-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    align-items: start;
}

.about-text {
    font-size: 1.0625rem;
    line-height: 1.9;
    color: var(--text-secondary);
}

.intro-text {
    font-size: 1.25rem;
    line-height: 1.8;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
    font-family: var(--font-serif);
}

.about-text p {
    margin-bottom: var(--spacing-md);
}

.about-image-placeholder {
    width: 100%;
    height: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
    position: sticky;
    top: 100px;
}

.about-image-placeholder img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.highlights {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
    margin-top: var(--spacing-xl);
}

.highlight-card {
    background: var(--background);
    padding: var(--spacing-md);
    border-left: 3px solid var(--accent-color);
    transition: transform var(--transition-medium);
}

.highlight-card:hover {
    transform: translateX(8px);
}

.highlight-title {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--primary-color);
}

.highlight-card p {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ===================================
   Publications Section
   =================================== */
.publications-section {
    background: linear-gradient(135deg, #f5f5f3 0%, #fafaf8 100%);
}

.publications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.publication-card {
    background: var(--white);
    border-radius: 4px;
    overflow: hidden;
    transition: transform var(--transition-medium), box-shadow var(--transition-medium);
    box-shadow: 0 2px 15px rgba(0, 0, 0, 0.05);
}

.publication-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}

.publication-image-placeholder {
    width: 100%;
    height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #f0f0ee 0%, #e8e8e6 100%);
}

.publication-image-placeholder img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.publication-info {
    padding: var(--spacing-md);
}

.publication-title {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-sm);
    color: var(--primary-color);
}

.publication-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
    line-height: 1.7;
}

.publication-meta {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
    font-style: italic;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--secondary-color);
    color: var(--white);
    padding: 0.75rem 1.5rem;
    border-radius: 4px;
    font-weight: 500;
    font-size: 0.95rem;
    transition: background var(--transition-fast), transform var(--transition-fast);
}

.download-btn:hover {
    background: var(--primary-color);
    color: var(--white);
    transform: translateY(-2px);
}

/* ===================================
   Contact Section
   =================================== */
.contact-section {
    background: var(--white);
}

.contact-content {
    max-width: 700px;
    margin: 0 auto;
    text-align: center;
}

.contact-content p {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.contact-details {
    margin-top: var(--spacing-md);
}

.contact-details p {
    margin-bottom: var(--spacing-sm);
}

.contact-details strong {
    color: var(--primary-color);
    font-weight: 500;
}

.contact-details a {
    color: var(--secondary-color);
    text-decoration: underline;
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: var(--primary-color);
    color: var(--white);
    padding: var(--spacing-md);
    text-align: center;
}

.footer p {
    font-size: 0.9rem;
    opacity: 0.9;
}

/* ===================================
   Placeholder Boxes
   =================================== */
.placeholder-box {
    background: linear-gradient(135deg, #f0f0ee 0%, #e8e8e6 100%);
    border: 2px dashed var(--border-color);
    border-radius: 4px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 100%;
    min-height: 300px;
    padding: var(--spacing-md);
    transition: border-color var(--transition-fast);
}

.placeholder-box:hover {
    border-color: var(--accent-color);
}

.placeholder-box.small {
    min-height: 200px;
}

/* Simulated Book Cover */
.book-cover-design {
    width: 100%;
    height: 100%;
    background: #f0f0ee;
    /* Light grey like other placeholders */
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    text-align: center;
    color: var(--text-primary);
    position: relative;
}

.book-cover-content {
    border: 1px solid var(--text-secondary);
    padding: 2rem 1rem;
    width: 100%;
    height: 90%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.book-author {
    font-family: var(--font-sans);
    text-transform: uppercase;
    letter-spacing: 0.2em;
    font-size: 0.8rem;
    margin-bottom: 1.5rem;
    opacity: 0.9;
    color: var(--text-secondary);
}

.book-title {
    font-family: var(--font-serif);
    font-size: 1.75rem;
    line-height: 1.2;
    font-weight: 400;
    color: var(--primary-color);
}

.placeholder-text {
    font-family: var(--font-sans);
    font-size: 1.25rem;
    color: var(--text-secondary);
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
}

.placeholder-hint {
    font-family: 'Courier New', monospace;
    font-size: 0.875rem;
    color: var(--text-light);
    background: rgba(255, 255, 255, 0.7);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 968px) {
    .hero {
        grid-template-columns: 1fr;
        min-height: auto;
        gap: var(--spacing-md);
    }

    .hero-title {
        font-size: 3rem;
    }

    .hero-image-placeholder {
        height: 400px;
    }

    .about-content {
        grid-template-columns: 1fr;
    }

    .about-image-placeholder {
        position: static;
    }

    .highlights {
        grid-template-columns: 1fr;
    }

    .nav-container {
        gap: var(--spacing-md);
    }
}

@media (max-width: 640px) {
    :root {
        --spacing-lg: 3rem;
        --spacing-xl: 4rem;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .section-title {
        font-size: 2.25rem;
    }

    .nav-container {
        flex-direction: column;
        gap: var(--spacing-sm);
        padding: var(--spacing-sm);
    }

    .language-switcher {
        top: var(--spacing-sm);
        right: var(--spacing-sm);
    }

    .publications-grid {
        grid-template-columns: 1fr;
    }
}

/* ===================================
   Smooth Animations
   =================================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.section {
    animation: fadeInUp var(--transition-slow) ease-out;
}