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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Arial', sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    padding: 80px 0;
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
}

.section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.85);
    z-index: 1;
}

#current::before {
    background: rgba(255, 255, 255, 0.8);
}

#education-grad::before {
    background: rgba(255, 255, 255, 0.85);
}

#research::before {
    background: rgba(255, 255, 255, 0.8);
}

#publications::before {
    background: rgba(255, 255, 255, 0.85);
}

#achievements::before {
    background: rgba(255, 255, 255, 0.8);
}

#education-undergrad::before {
    background: rgba(255, 255, 255, 0.85);
}

#skills::before {
    background: rgba(255, 255, 255, 0.8);
}

.section .container {
    position: relative;
    z-index: 2;
}

/* Hero Section */
#hero {
    background-image: linear-gradient(rgba(102, 126, 234, 0.8), rgba(118, 75, 162, 0.8)), url('https://images.unsplash.com/photo-1451187580459-43490279c0fa?ixlib=rb-4.0.3&ixid=M3wxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8fA%3D%3D&auto=format&fit=crop&w=2072&q=80');
    color: white;
    text-align: center;
}

#hero::before {
    display: none;
}

#hero h1 {
    font-size: 4rem;
    margin-bottom: 20px;
    font-weight: 700;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

#hero h2 {
    font-size: 2rem;
    margin-bottom: 20px;
    font-weight: 300;
}

#hero p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    opacity: 0.9;
}

/* Social Links */
.social-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 40px;
}

.social-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    background: rgba(255, 255, 255, 0.1);
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    text-decoration: none;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
}

.social-link:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: rgba(255, 255, 255, 0.6);
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

.social-icon {
    width: 24px;
    height: 24px;
    fill: white;
    transition: all 0.3s ease;
}

.social-link:hover .social-icon {
    transform: scale(1.1);
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
}

.arrow-down {
    width: 20px;
    height: 20px;
    border-right: 2px solid white;
    border-bottom: 2px solid white;
    transform: rotate(45deg);
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0) rotate(45deg);
    }
    40% {
        transform: translateY(-10px) rotate(45deg);
    }
    60% {
        transform: translateY(-5px) rotate(45deg);
    }
}

/* Individual Section Backgrounds */
#current {
    background-image: url('https://images.unsplash.com/photo-1497366216548-37526070297c?ixlib=rb-4.0.3&auto=format&fit=crop&w=2069&q=80');
}

#education-grad {
    background-image: url('https://images.unsplash.com/photo-1507003211169-0a1dd7228f2d?ixlib=rb-4.0.3&auto=format&fit=crop&w=2070&q=80');
}

#research {
    background-image: url('https://images.unsplash.com/photo-1532094349884-543bc11b234d?ixlib=rb-4.0.3&auto=format&fit=crop&w=2070&q=80');
}

#publications {
    background-image: url('https://images.unsplash.com/photo-1481627834876-b7833e8f5570?ixlib=rb-4.0.3&auto=format&fit=crop&w=2128&q=80');
}

#achievements {
    background-image: url('https://images.unsplash.com/photo-1559136555-9303baea8ebd?ixlib=rb-4.0.3&auto=format&fit=crop&w=2070&q=80');
}

#education-undergrad {
    background-image: url('https://images.unsplash.com/photo-1523050854058-8df90110c9f1?ixlib=rb-4.0.3&auto=format&fit=crop&w=2070&q=80');
}

#skills {
    background-image: url('https://images.unsplash.com/photo-1517180102446-f3ece451e9d8?ixlib=rb-4.0.3&auto=format&fit=crop&w=2070&q=80');
}

/* Typography */
h2 {
    font-size: 2.5rem;
    margin-bottom: 40px;
    text-align: center;
    color: #333;
    position: relative;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

h2::after {
    content: '';
    display: block;
    width: 80px;
    height: 3px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    margin: 20px auto;
}

h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: #444;
}

/* Job Cards */
.job-card, .education-card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
    transform: translateY(20px);
    opacity: 0;
    animation: fadeInUp 1s ease forwards;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.job-card h3, .education-card h3 {
    font-size: 2rem;
    color: #667eea;
    margin-bottom: 10px;
}

.location, .years {
    color: #666;
    font-style: italic;
    margin-bottom: 20px;
}

.degree {
    font-size: 1.2rem;
    color: #764ba2;
    font-weight: 600;
    margin-bottom: 10px;
}

.description {
    font-size: 1.1rem;
    line-height: 1.8;
}

/* Research Grid */
.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.research-item {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
    text-align: center;
    transition: transform 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.research-item:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.2);
}

/* Publications */
.publication-list {
    max-width: 800px;
    margin: 0 auto;
}

.publication-item {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 30px;
    margin-bottom: 20px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
    border-left: 4px solid #667eea;
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-left: 4px solid #667eea;
}

.publication-item h3 {
    color: #333;
    margin-bottom: 10px;
}

.journal {
    color: #764ba2;
    font-weight: 600;
    font-style: italic;
}

/* Achievements Grid */
.achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
    margin-top: 40px;
}

.cert-section, .patent-section {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

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

.cert-section li {
    padding: 8px 0;
    border-bottom: 1px solid #eee;
    position: relative;
    padding-left: 20px;
}

.cert-section li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: #667eea;
    font-weight: bold;
}

.patent-year {
    color: #666;
    font-style: italic;
}

/* Skills Grid */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
    margin-top: 40px;
}

.skills-category, .languages-category {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.skills-category ul, .languages-category ul {
    list-style: none;
}

.skills-category li, .languages-category li {
    padding: 10px 0;
    border-bottom: 1px solid #eee;
    position: relative;
    padding-left: 20px;
}

.skills-category li::before, .languages-category li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: #764ba2;
    font-weight: bold;
    font-size: 1.2rem;
}

/* Table of Contents */
.toc-container {
    position: fixed;
    top: 50%;
    left: 0;
    transform: translateY(-50%);
    z-index: 9999;
}

.toc-toggle {
    position: absolute;
    top: 0;
    left: 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 15px 8px;
    cursor: pointer;
    border-radius: 0 8px 8px 0;
    box-shadow: 5px 0 15px rgba(0,0,0,0.2);
    transition: all 0.3s ease;
    z-index: 10001;
}

.toc-toggle:hover {
    background: linear-gradient(135deg, #5a6fd8 0%, #6b4190 100%);
    transform: translateX(5px);
}

.toc-icon {
    font-size: 1.5rem;
    font-weight: bold;
    display: block;
    writing-mode: vertical-rl;
    text-orientation: mixed;
}

.toc {
    position: fixed;
    top: 50%;
    left: -320px;
    transform: translateY(-50%);
    width: 320px;
    max-height: 70vh;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    box-shadow: 10px 0 30px rgba(0,0,0,0.2);
    border-radius: 0 15px 15px 0;
    transition: left 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    overflow-y: auto;
    z-index: 10000;
}

.toc.active {
    left: 0;
}

.toc-container.toc-open .toc-toggle {
    opacity: 0;
    pointer-events: none;
}

.toc-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 25px 15px;
    border-bottom: 2px solid #e0e0e0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 0 15px 0 0;
}

.toc-header h3 {
    margin: 0;
    font-size: 1.4rem;
    font-weight: 600;
}

.toc-close {
    background: none;
    border: none;
    color: white;
    font-size: 2rem;
    cursor: pointer;
    padding: 0;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: background 0.3s ease;
}

.toc-close:hover {
    background: rgba(255, 255, 255, 0.2);
}

.toc-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.toc-list li {
    border-bottom: 1px solid #e0e0e0;
}

.toc-list a {
    display: block;
    padding: 18px 25px;
    text-decoration: none;
    color: #333;
    font-weight: 500;
    font-size: 1rem;
    transition: all 0.3s ease;
    position: relative;
    border-left: 4px solid transparent;
}

.toc-list a:hover {
    background: linear-gradient(90deg, rgba(102, 126, 234, 0.1) 0%, rgba(118, 75, 162, 0.1) 100%);
    border-left-color: #667eea;
    transform: translateX(5px);
    color: #667eea;
}

.toc-list a.active {
    background: linear-gradient(90deg, rgba(102, 126, 234, 0.15) 0%, rgba(118, 75, 162, 0.15) 100%);
    border-left-color: #764ba2;
    color: #764ba2;
    font-weight: 600;
}

.toc-list a.active::after {
    content: '';
    position: absolute;
    right: 15px;
    top: 50%;
    transform: translateY(-50%);
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: #764ba2;
}

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

@keyframes slideInFromRight {
    from {
        right: -350px;
    }
    to {
        right: 0;
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    #hero h1 {
        font-size: 2.5rem;
    }
    
    #hero h2 {
        font-size: 1.5rem;
    }
    
    .section {
        padding: 40px 0;
    }
    
    .research-grid, .achievements-grid, .skills-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .job-card, .education-card {
        padding: 20px;
    }

    /* TOC Mobile Adjustments */
    .toc {
        width: 280px;
        left: -280px;
        max-height: 60vh;
    }
    
    .toc-toggle {
        padding: 12px 6px;
    }
    
    .toc-icon {
        font-size: 1.3rem;
    }
    
    /* Social Links Mobile */
    .social-links {
        gap: 15px;
    }
    
    .social-link {
        width: 45px;
        height: 45px;
    }
    
    .social-icon {
        width: 20px;
        height: 20px;
    }
}

@media (max-width: 480px) {
    #hero h1 {
        font-size: 2rem;
    }
    
    h2 {
        font-size: 2rem;
    }
    
    .container {
        padding: 0 15px;
    }
}