/* Modern CSS Reset */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* CSS Variables for Design System */
:root {
    --primary-color: #6366f1;
    --primary-light: #8b5cf6;
    --primary-dark: #4f46e5;
    --secondary-color: #06b6d4;
    --accent-color: #f59e0b;
    
    --bg-primary: #0f0f23;
    --bg-secondary: #1a1a2e;
    --bg-tertiary: #16213e;
    --bg-card: rgba(255, 255, 255, 0.05);
    --bg-card-hover: rgba(255, 255, 255, 0.08);
    
    --text-primary: #ffffff;
    --text-secondary: #e2e8f0;
    --text-muted: #94a3b8;
    --text-light: #cbd5e1;
    
    --gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
    --gradient-secondary: linear-gradient(135deg, #06b6d4 0%, #0ea5e9 100%);
    --gradient-accent: linear-gradient(135deg, #f59e0b 0%, #f97316 100%);
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --border-radius-lg: 16px;
    
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: all 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    
    --container-max-width: 1200px;
    --container-padding: 2rem;
    
    --font-primary: 'Inter', sans-serif;
    --font-heading: 'Space Grotesk', sans-serif;
}

/* Base Styles */
html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    background: var(--bg-primary);
    color: var(--text-secondary);
    line-height: 1.6;
    overflow-x: hidden;
}

/* Container */
.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    color: var(--text-primary);
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 {
    font-size: 3.5rem;
    font-weight: 700;
}

h2 {
    font-size: 2.5rem;
    font-weight: 600;
}

h3 {
    font-size: 1.875rem;
    font-weight: 600;
}

p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

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

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

/* Gradient Text */
.gradient-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    padding: 0.75rem 2rem;
    font-weight: 500;
    font-size: 1rem;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    font-family: var(--font-primary);
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
    background: var(--primary-color);
    color: white;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(15, 15, 35, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    padding: 1rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

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

.nav-brand a {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
}

.nav-menu {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    transition: var(--transition-fast);
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: var(--transition-fast);
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    margin: 3px 0;
    transition: var(--transition-fast);
}

/* Hero Section */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 8rem 0;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--bg-primary);
    z-index: -1;
}

.hero-grid {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        linear-gradient(rgba(99, 102, 241, 0.1) 1px, transparent 1px),
        linear-gradient(90deg, rgba(99, 102, 241, 0.1) 1px, transparent 1px);
    background-size: 50px 50px;
    animation: gridMove 20s linear infinite;
}

@keyframes gridMove {
    0% { transform: translate(0, 0); }
    100% { transform: translate(50px, 50px); }
}

.hero-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.hero-badge {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.3);
    border-radius: 50px;
    color: var(--primary-color);
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 2rem;
}

.hero-title {
    font-size: 4rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-tags {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
}

.tag {
    padding: 0.5rem 1rem;
    background: var(--bg-card);
    border-radius: var(--border-radius);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-light);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.hero-cta {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 3rem;
}

.hero-social {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    background: var(--bg-card);
    border-radius: var(--border-radius);
    color: var(--text-secondary);
    transition: var(--transition);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

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

/* About Section */
.about {
    padding: 8rem 0;
    background: var(--bg-secondary);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: 4rem;
    align-items: start;
}

.about-text {
    max-width: 600px;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

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

.about-stats {
    display: flex;
    gap: 2rem;
    margin-top: 3rem;
}

.stat {
    text-align: center;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    font-family: var(--font-heading);
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-top: 0.5rem;
}

.about-profile {
    background: var(--bg-card);
    border-radius: var(--border-radius-lg);
    padding: 2rem;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.profile-image {
    text-align: center;
    margin-bottom: 2rem;
}

.profile-image img {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--primary-color);
}

.profile-info {
    margin-bottom: 2rem;
}

.info-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

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

.info-label {
    font-weight: 500;
    color: var(--text-muted);
}

.info-value {
    color: var(--text-primary);
    font-weight: 500;
}

.certifications {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
}

.cert-item {
    background: var(--bg-tertiary);
    border-radius: var(--border-radius);
    padding: 1rem;
    text-align: center;
    transition: var(--transition);
}

.cert-item:hover {
    transform: translateY(-2px);
}

.cert-item img {
    width: 60px;
    height: 60px;
    object-fit: contain;
}

/* Section Headers */
.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto;
}

/* Expertise Section */
.expertise {
    padding: 8rem 0;
    background: var(--bg-primary);
}

.expertise-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.expertise-card {
    background: var(--bg-card);
    border-radius: var(--border-radius-lg);
    padding: 2.5rem;
    text-align: center;
    transition: var(--transition);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.expertise-card:hover {
    transform: translateY(-5px);
    background: var(--bg-card-hover);
    box-shadow: var(--shadow-xl);
}

.card-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.card-icon i {
    font-size: 2rem;
    color: white;
}

.expertise-card h3 {
    margin-bottom: 1rem;
    color: var(--text-primary);
}

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

/* Showcase Section */
.showcase {
    padding: 8rem 0;
    background: var(--bg-secondary);
}

.showcase-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
    gap: 3rem;
}

.showcase-card {
    background: var(--bg-card);
    border-radius: var(--border-radius-lg);
    padding: 2.5rem;
    transition: var(--transition);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.showcase-card:hover {
    transform: translateY(-3px);
    background: var(--bg-card-hover);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1.5rem;
}

.card-header h3 {
    margin: 0;
    color: var(--text-primary);
}

.card-header h3 a {
    color: var(--text-primary);
    transition: var(--transition-fast);
}

.card-header h3 a:hover {
    color: var(--primary-color);
}

.card-badge {
    background: var(--gradient-secondary);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 500;
    white-space: nowrap;
}

.card-description {
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.7;
}

.card-features {
    margin-bottom: 2rem;
}

.feature {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.feature i {
    color: var(--primary-color);
    width: 20px;
}

.feature span {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.card-impact {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.6;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

/* Content Section */
.content {
    padding: 8rem 0;
    background: var(--bg-primary);
}

.content-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.content-card {
    background: var(--bg-card);
    border-radius: var(--border-radius-lg);
    padding: 2.5rem;
    transition: var(--transition);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.content-card:hover {
    transform: translateY(-3px);
    background: var(--bg-card-hover);
}

.content-card .card-icon {
    width: 60px;
    height: 60px;
    margin: 0 0 1.5rem 0;
    background: var(--gradient-accent);
}

.content-card .card-icon i {
    font-size: 1.5rem;
}

.content-card h3 {
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.content-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    margin-bottom: 2rem;
}

.content-list a {
    color: var(--text-secondary);
    font-size: 0.9rem;
    transition: var(--transition-fast);
    padding: 0.5rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.content-list a:hover {
    color: var(--primary-color);
}

.content-topics {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1.5rem;
}

.topic {
    background: var(--bg-tertiary);
    color: var(--text-light);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 500;
}

.content-ref {
    color: var(--text-muted);
    font-size: 0.9rem;
    font-style: italic;
    padding: 0.5rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.expand-btn {
    background: var(--gradient-primary);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    margin: 1rem 0;
}

.expand-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.recent-talks {
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    padding-bottom: 1rem;
    margin-bottom: 1rem;
}

.historical-talks {
    display: none;
    flex-direction: column;
    gap: 0.75rem;
}

/* Contact Section */
.contact {
    padding: 8rem 0;
    background: var(--bg-secondary);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
}

.contact-icon {
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.contact-icon i {
    color: white;
    font-size: 1.25rem;
}

.contact-details h3 {
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.contact-details p {
    color: var(--text-secondary);
    margin: 0;
}

.contact-form {
    background: var(--bg-card);
    border-radius: var(--border-radius-lg);
    padding: 2.5rem;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 1rem;
    background: var(--bg-tertiary);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius);
    color: var(--text-primary);
    font-family: var(--font-primary);
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-group textarea {
    height: 120px;
    resize: vertical;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--text-muted);
}

/* Footer */
.footer {
    padding: 2rem 0;
    background: var(--bg-primary);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-text p {
    color: var(--text-muted);
    margin: 0;
}

.footer-social {
    display: flex;
    gap: 1rem;
}

.footer-social a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--bg-card);
    border-radius: 50%;
    color: var(--text-secondary);
    transition: var(--transition);
}

.footer-social a:hover {
    background: var(--primary-color);
    color: white;
}

/* Responsive Design */
@media (max-width: 768px) {
    :root {
        --container-padding: 1rem;
    }
    
    .nav-menu {
        position: fixed;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg-secondary);
        flex-direction: column;
        padding: 2rem;
        transition: var(--transition);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-cta {
        flex-direction: column;
        align-items: center;
    }
    
    .hero-tags {
        flex-direction: column;
        align-items: center;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .about-stats {
        justify-content: center;
    }
    
    .expertise-grid {
        grid-template-columns: 1fr;
    }
    
    .showcase-grid {
        grid-template-columns: 1fr;
    }
    
    .content-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .certifications {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .about-stats {
        flex-direction: column;
        align-items: center;
        gap: 1rem;
    }
    
    .certifications {
        grid-template-columns: 1fr;
    }
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-content > * {
    animation: fadeInUp 0.6s ease-out;
}

.hero-badge {
    animation-delay: 0.1s;
}

.hero-title {
    animation-delay: 0.2s;
}

.hero-subtitle {
    animation-delay: 0.3s;
}

.hero-tags {
    animation-delay: 0.4s;
}

.hero-cta {
    animation-delay: 0.5s;
}

.hero-social {
    animation-delay: 0.6s;
}