:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --accent-color: #ec4899;
    --bg-dark: #0a0a0f;
    --bg-darker: #050508;
    --bg-card: #111118;
    --text-primary: #ffffff;
    --text-secondary: #a0a0b0;
    --gradient-1: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #ec4899 100%);
    --gradient-2: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

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

body {
    font-family: 'Inter', sans-serif;
    background: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Progress Bar (Left Side) */
.progress-bar-container {
    position: fixed;
    left: 20px;
    top: 50%;
    transform: translateY(-50%);
    z-index: 999;
    display: flex;
    align-items: center;
    gap: 12px;
}

.progress-bar-track {
    width: clamp(1.5px, 0.15vw + 1px, 2px);
    height: clamp(150px, 18vh, 220px);
    background: rgba(255, 255, 255, 0.1);
    position: relative;
    border-radius: 2px;
}

.progress-bar {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 0%;
    background: var(--gradient-1);
    border-radius: 2px;
    transition: height 0.1s ease-out;
    box-shadow: 0 0 8px rgba(99, 102, 241, 0.6);
}

.progress-sections {
    display: flex;
    flex-direction: column;
    gap: clamp(1rem, 2vh, 2rem);
    align-items: center;
}

.progress-section {
    position: relative;
    cursor: pointer;
    transition: all 0.3s ease;
}

.progress-dot {
    display: block;
    width: clamp(4px, 0.4vw + 3px, 6px);
    height: clamp(4px, 0.4vw + 3px, 6px);
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    border: clamp(1px, 0.1vw + 0.5px, 1.5px) solid transparent;
    transition: all 0.3s ease;
}

.progress-section.active .progress-dot {
    background: var(--primary-color);
    border-color: var(--primary-color);
    box-shadow: 0 0 12px rgba(99, 102, 241, 0.8);
    transform: scale(1.5);
}

.progress-section.completed .progress-dot {
    background: var(--primary-color);
    border-color: var(--primary-color);
    opacity: 0.6;
}

.progress-section:hover .progress-dot {
    transform: scale(1.3);
    background: var(--primary-color);
}

.progress-section::after {
    content: attr(title);
    position: absolute;
    left: 20px;
    top: 50%;
    transform: translateY(-50%);
    white-space: nowrap;
    font-size: 0.75rem;
    color: var(--text-secondary);
    opacity: 0;
    transition: opacity 0.3s ease;
    pointer-events: none;
    background: rgba(10, 10, 15, 0.9);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.progress-section:hover::after {
    opacity: 1;
}

/* Tablet styles */
@media (max-width: 1024px) and (min-width: 769px) {
    .hero {
        padding: 0rem 2rem 3rem;
    }
    
    .progress-bar-container {
        left: 15px;
    }
    
    .progress-bar-track {
        height: clamp(140px, 16vh, 180px);
    }
}

/* Mobile and small tablet */
@media (max-width: 768px) {
    .hero {
        padding: 0rem 1.5rem 3rem;
        min-height: 100vh;
        align-items: center;
    }
    
    .hero-content {
        align-items: center;
    }
    
    .progress-bar-container {
        left: 10px;
    }
    
    .progress-bar-track {
        height: clamp(120px, 14vh, 160px);
    }
    
    .progress-sections {
        gap: clamp(0.75rem, 1.5vh, 1.25rem);
    }
    
    .progress-section::after {
        display: none;
    }
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(10, 10, 15, 0.8);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo .logo-text {
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-1);
    transition: width 0.3s ease;
}

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

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.hamburger span {
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    transition: all 0.3s ease;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    margin-top: -5rem;
    padding: 0rem 2rem 4rem;
    overflow: hidden;
}

.particles-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

.particle {
    position: absolute;
    width: 4px;
    height: 4px;
    background: var(--primary-color);
    border-radius: 50%;
    opacity: 0.6;
    animation: float 20s infinite;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0) translateX(0);
        opacity: 0.6;
    }
    50% {
        transform: translateY(-100px) translateX(50px);
        opacity: 0.2;
    }
}

.hero-content {
    max-width: 1200px;
    width: 100%;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    position: relative;
    z-index: 2;
}

.hero-text {
    animation: fadeInUp 1s ease;
    margin-left: 2rem;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1.5rem;
}

.gradient-text {
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: block;
}

.hero-subtitle {
    display: block;
    color: var(--text-secondary);
    font-weight: 400;
}

.hero-description {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

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

.hero-details {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
    line-height: 1.7;
}

.bio-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    border-bottom: 1px solid transparent;
}

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

.hero-details strong {
    color: var(--text-primary);
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.social-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    color: var(--text-primary);
    text-decoration: none;
    transition: all 0.3s ease;
    font-weight: 500;
}

.social-link svg {
    width: 20px;
    height: 20px;
}

.social-link:hover {
    border-color: var(--primary-color);
    background: rgba(99, 102, 241, 0.1);
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.btn {
    padding: 0.875rem 2rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-block;
}

.btn-primary {
    background: var(--gradient-1);
    color: white;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.6);
}

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

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

/* Hero Visual - Portrait */
.hero-visual {
    position: relative;
    height: 1000px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.portrait-container {
    position: absolute;
    width: 300px;
    height: 300px;
    cursor: move;
    user-select: none;
    top: 50%;
    left: 50%;
    margin-top: -125px;
    margin-left: -125px;
    transition: transform 0.1s ease-out;
}

.portrait-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 50%;
    box-shadow: 0 0px 0px rgba(99, 102, 241, 0.4);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    position: relative;
    z-index: 2;
    -webkit-user-drag: none;
    -khtml-user-drag: none;
    -moz-user-drag: none;
    -o-user-drag: none;
    user-drag: none;
    user-select: none;
    -webkit-touch-callout: none;
    pointer-events: none;
}

.portrait-container:hover .portrait-image {
    transform: scale(1.05);
    box-shadow: 0 15px 50px rgba(99, 102, 241, 0.6);
}

.portrait-glow {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 280px;
    height: 280px;
    border-radius: 50%;
    background: var(--gradient-1);
    opacity: 0.3;
    filter: blur(20px);
    animation: pulse-glow 3s ease-in-out infinite;
    z-index: 1;
}

@keyframes pulse-glow {
    0%, 100% {
        transform: translate(-50%, -50%) scale(1);
        opacity: 0.3;
    }
    50% {
        transform: translate(-50%, -50%) scale(1.1);
        opacity: 0.5;
    }
}

.portrait-container.dragging {
    cursor: grabbing;
}

.portrait-container.dragging .portrait-image {
    transform: scale(1.1);
    box-shadow: 0 20px 60px rgba(99, 102, 241, 0.8);
}

.diffusion-circle {
    width: 300px;
    height: 300px;
    border: 2px solid var(--primary-color);
    border-radius: 50%;
    position: absolute;
    animation: pulse 3s ease-in-out infinite;
    opacity: 0.6;
}

.diffusion-circle::before,
.diffusion-circle::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    border: 2px solid var(--secondary-color);
    border-radius: 50%;
    animation: pulse 3s ease-in-out infinite;
}

.diffusion-circle::before {
    width: 200px;
    height: 200px;
    animation-delay: 0.5s;
    opacity: 0.4;
}

.diffusion-circle::after {
    width: 100px;
    height: 100px;
    animation-delay: 1s;
    opacity: 0.3;
}

@keyframes pulse {
    0%, 100% {
        transform: translate(-50%, -50%) scale(1);
        opacity: 0.6;
    }
    50% {
        transform: translate(-50%, -50%) scale(1.1);
        opacity: 0.3;
    }
}

/* Robot Arm Animation */
.robot-arm {
    position: absolute;
    width: 200px;
    height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
    animation: rotate 20s linear infinite;
}

.arm-segment {
    width: 60px;
    height: 8px;
    background: var(--gradient-1);
    border-radius: 4px;
    position: absolute;
    transform-origin: left center;
    box-shadow: 0 0 10px rgba(99, 102, 241, 0.5);
}

.arm-segment:nth-child(1) {
    transform: rotate(45deg);
    animation: move1 4s ease-in-out infinite;
}

.arm-segment:nth-child(2) {
    transform: rotate(90deg) translateX(60px);
    animation: move2 4s ease-in-out infinite;
}

.arm-segment:nth-child(3) {
    transform: rotate(135deg) translateX(120px);
    animation: move3 4s ease-in-out infinite;
}

.arm-gripper {
    width: 20px;
    height: 20px;
    border: 2px solid var(--accent-color);
    border-radius: 50%;
    position: absolute;
    transform: translate(180px, 0);
    animation: grip 2s ease-in-out infinite;
}

@keyframes move1 {
    0%, 100% { transform: rotate(45deg); }
    50% { transform: rotate(60deg); }
}

@keyframes move2 {
    0%, 100% { transform: rotate(90deg) translateX(60px); }
    50% { transform: rotate(75deg) translateX(60px); }
}

@keyframes move3 {
    0%, 100% { transform: rotate(135deg) translateX(120px); }
    50% { transform: rotate(120deg) translateX(120px); }
}

@keyframes grip {
    0%, 100% { transform: translate(180px, 0) scale(1); }
    50% { transform: translate(180px, 0) scale(1.2); }
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.scroll-indicator {
    position: absolute;
    bottom: 13rem;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
}

.scroll-arrow {
    width: 2px;
    height: 30px;
    background: var(--gradient-1);
    position: relative;
    animation: scroll 2s ease-in-out infinite;
}

.scroll-arrow::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: -4px;
    width: 10px;
    height: 10px;
    border-right: 2px solid var(--primary-color);
    border-bottom: 2px solid var(--primary-color);
    transform: rotate(45deg);
}

@keyframes scroll {
    0%, 100% { transform: translateY(0); opacity: 1; }
    50% { transform: translateY(10px); opacity: 0.5; }
}

/* Section Styles */
section {
    padding: 6rem 0;
    position: relative;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    text-align: center;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* About Section */
.about {
    background: var(--bg-darker);
}

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

.about-text p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.about-text strong {
    color: var(--text-primary);
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.research-areas {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-top: 2rem;
}

.research-tag {
    padding: 0.5rem 1.5rem;
    background: var(--bg-card);
    border: 1px solid rgba(99, 102, 241, 0.3);
    border-radius: 20px;
    color: var(--text-primary);
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.research-tag:hover {
    border-color: var(--primary-color);
    background: rgba(99, 102, 241, 0.1);
    transform: translateY(-2px);
}

/* Research Section */
.research {
    background: var(--bg-darker);
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.research-card {
    background: var(--bg-card);
    padding: 2.5rem;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.research-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--gradient-1);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.research-card:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.2);
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1) 0%, rgba(139, 92, 246, 0.1) 100%);
}

.research-card:hover::before {
    transform: scaleX(1);
}

.card-icon {
    width: 60px;
    height: 40px;
    margin-bottom: 3rem;
    color: var(--primary-color);
    background: transparent;
}

.card-icon svg {
    width: 150%;
    height: 150%;
    background: transparent;
    display: block;
}

.research-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

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

/* Publications Section */
.publications {
    background: transparent;
}

.publications-list {
    max-width: 1000px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 2.5rem;
}

.publication-item {
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: 2rem;
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.publication-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--gradient-1);
    transform: scaleY(0);
    transition: transform 0.3s ease;
}

.publication-item:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.2);
}

.publication-item:hover::before {
    transform: scaleY(1);
}

.publication-image {
    width: 200px;
    height: 150px;
    border-radius: 8px;
    overflow: hidden;
    background: var(--bg-darker);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.publication-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.publication-item:hover .publication-image img {
    transform: scale(1.05);
}

.publication-content {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.publication-title {
    font-size: 1.3rem;
    font-weight: 600;
    margin: 0;
    line-height: 1.4;
}

.publication-title a {
    color: var(--text-primary);
    text-decoration: none;
    transition: color 0.3s ease;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.publication-title a:hover {
    color: var(--accent-color);
    -webkit-text-fill-color: var(--accent-color);
}

.publication-authors {
    color: var(--text-secondary);
    font-size: 1rem;
    margin: 0;
    line-height: 1.6;
}

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

.publication-venue {
    color: var(--primary-color);
    font-size: 0.95rem;
    font-weight: 500;
    margin: 0;
    font-style: italic;
}

.publication-bib {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin: 0;
    line-height: 1.6;
}

@media (max-width: 768px) {
    .publication-item {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .publication-image {
        width: 100%;
        height: 200px;
    }
}

/* Contact Section */
.contact-content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.contact-content p {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.contact-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.contact-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem 2rem;
    background: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    color: var(--text-primary);
    text-decoration: none;
    transition: all 0.3s ease;
}

.contact-link svg {
    width: 24px;
    height: 24px;
}

.contact-link:hover {
    border-color: var(--primary-color);
    background: rgba(99, 102, 241, 0.1);
    transform: translateY(-2px);
}

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

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

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

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: var(--bg-darker);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        padding: 2rem 0;
        border-top: 1px solid rgba(255, 255, 255, 0.1);
    }

    .nav-menu.active {
        left: 0;
    }

    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

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

    .hero-visual {
        height: 300px;
        margin-top: 2rem;
    }

    .portrait-container {
        width: 200px;
        height: 200px;
        margin-top: -100px;
        margin-left: -100px;
    }

    .hero-social {
        justify-content: center;
    }

    .hero-info {
        text-align: center;
    }

    .section-title {
        font-size: 2rem;
    }

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

    .contact-links {
        flex-direction: column;
        align-items: center;
    }
}

/* Small mobile */
@media (max-width: 480px) {
    .hero {
        padding: 0rem 1rem 2rem;
        min-height: 100vh;
        align-items: center;
    }
    
    .hero-title {
        font-size: 2rem;
    }

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

    .btn {
        padding: 0.75rem 1.5rem;
        font-size: 0.9rem;
    }
    
    .progress-bar-container {
        left: 8px;
    }
    
    .progress-bar-track {
        height: clamp(100px, 12vh, 140px);
    }
    
    .progress-sections {
        gap: clamp(0.5rem, 1.2vh, 1rem);
    }
}

/* Large screens */
@media (min-width: 1920px) {
    .progress-bar-container {
        left: 30px;
    }
    
    .progress-bar-track {
        height: 220px;
    }
    
    .progress-sections {
        gap: 2.25rem;
    }
}