/* ============================================
   Applied Science Research Institute - Academic Design
   ============================================ */

:root {
    /* Academic Color Palette - Clean and Professional */
    --primary-blue: #2563eb;
    --secondary-blue: #3b82f6;
    --accent-blue: #60a5fa;
    --text-primary: #1f2937;
    --text-secondary: #4b5563;
    --text-muted: #6b7280;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --border-color: #e5e7eb;
    --border-accent: #d1d5db;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
    
    /* Typography */
    --font-heading: 'Crimson Text', Georgia, serif;
    --font-body: 'Source Sans Pro', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

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

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

/* ============================================
   Navigation
   ============================================ */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    padding: var(--spacing-sm) 0;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.nav-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

.nav-links {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 400;
    font-size: 0.95rem;
    transition: color 0.3s ease;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-blue);
    transition: width 0.3s ease;
}

.nav-links a:hover {
    color: var(--text-primary);
}

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

/* ============================================
   Hero Section
   ============================================ */

.hero {
    min-height: 90vh;
    display: flex;
    align-items: center;
    padding: var(--spacing-xl) 0;
    margin-top: 80px;
    background: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
}

.hero-content {
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
}

.hero-badge {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    font-weight: 400;
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

.hero-title {
    font-family: var(--font-heading);
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.8;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
}

.stat-item {
    padding: var(--spacing-md);
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-blue);
    font-family: var(--font-body);
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* ============================================
   Sections
   ============================================ */

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

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.section-title {
    font-family: var(--font-heading);
    font-size: clamp(2rem, 4vw, 2.75rem);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ============================================
   Research Section
   ============================================ */

.research-section {
    background: var(--bg-secondary);
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.research-card {
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: var(--spacing-md);
    transition: all 0.3s ease;
    position: relative;
}

.research-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    border-color: var(--border-accent);
}

.research-number {
    font-size: 3rem;
    font-weight: 300;
    color: var(--primary-blue);
    opacity: 0.3;
    font-family: var(--font-body);
    margin-bottom: var(--spacing-xs);
    line-height: 1;
}

.research-card h3 {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
    font-weight: 600;
}

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

/* ============================================
   Publications Section
   ============================================ */

.publications-section {
    background: var(--bg-primary);
}

.publications-content {
    max-width: 900px;
    margin: 0 auto;
}

.publication-item {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-md);
    background: var(--bg-secondary);
    border-left: 3px solid var(--primary-blue);
    border-radius: 4px;
    transition: all 0.3s ease;
}

.publication-item:hover {
    background: var(--bg-tertiary);
    transform: translateX(5px);
}

.publication-year {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--primary-blue);
    min-width: 60px;
    font-family: var(--font-body);
}

.publication-text h3 {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
    font-weight: 600;
}

.publication-authors {
    font-size: 0.9rem;
    color: var(--text-muted);
    font-style: italic;
    margin-bottom: var(--spacing-sm);
}

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

.publication-link {
    color: var(--primary-blue);
    text-decoration: none;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    transition: gap 0.3s ease;
    font-size: 0.95rem;
}

.publication-link:hover {
    gap: var(--spacing-sm);
    text-decoration: underline;
}

/* ============================================
   Data Section
   ============================================ */

.data-section {
    background: var(--bg-secondary);
}

.data-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.data-card {
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: var(--spacing-md);
    transition: all 0.3s ease;
}

.data-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    border-color: var(--border-accent);
}

.data-card h3 {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
    font-weight: 600;
}

.data-card p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.7;
}

.data-link {
    color: var(--primary-blue);
    text-decoration: none;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    transition: gap 0.3s ease;
    font-size: 0.95rem;
}

.data-link:hover {
    gap: var(--spacing-sm);
    text-decoration: underline;
}

/* ============================================
   About Section
   ============================================ */

.about-section {
    background: var(--bg-primary);
    padding: var(--spacing-xl) 0;
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.about-content h2 {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
    font-weight: 600;
}

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

/* ============================================
   Contact Section
   ============================================ */

.contact-section {
    background: var(--bg-secondary);
    padding: var(--spacing-xl) 0;
}

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

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

.contact-info {
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: var(--spacing-md);
    text-align: left;
    max-width: 500px;
    margin: 0 auto;
}

.contact-info p {
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
    line-height: 1.7;
}

.contact-info strong {
    color: var(--text-primary);
    font-weight: 600;
}

/* ============================================
   Footer
   ============================================ */

.footer {
    background: var(--bg-primary);
    border-top: 1px solid var(--border-color);
    padding: var(--spacing-lg) 0 var(--spacing-md);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.footer-section h4 {
    font-family: var(--font-heading);
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
    font-weight: 600;
    font-size: 1.125rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: var(--spacing-xs);
}

.footer-section a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.3s ease;
    font-size: 0.95rem;
}

.footer-section a:hover {
    color: var(--primary-blue);
}

.footer-section p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.7;
    margin-top: var(--spacing-sm);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* ============================================
   Responsive Design
   ============================================ */

@media (max-width: 768px) {
    .nav-links {
        flex-direction: column;
        gap: var(--spacing-xs);
        font-size: 0.9rem;
    }
    
    .hero-stats {
        grid-template-columns: 1fr;
    }
    
    .research-grid,
    .data-grid {
        grid-template-columns: 1fr;
    }
    
    .publication-item {
        flex-direction: column;
    }
    
    .publication-year {
        min-width: auto;
    }
    
    .about-content p {
        text-align: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .hero {
        padding: var(--spacing-lg) 0;
    }
    
    .section-header {
        text-align: left;
    }
}