/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #ffffff;
}

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

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    padding: 1rem 0;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
}

.nav-logo h2 {
    color: #2563eb;
    font-weight: 700;
    position: absolute;
    left: 20px;
}

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

.nav-link {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-link:hover {
    color: #2563eb;
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    position: absolute;
    right: 20px;
}

.bar {
    width: 25px;
    height: 3px;
    background-color: #333;
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    padding: 120px 0 80px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    min-height: 100vh;
    display: flex;
    align-items: center;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 2rem;
}

.hero-contact-info {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 15px;
    padding: 1.5rem;
    border: 1px solid rgba(255, 255, 255, 0.2);
    margin-top: 2rem;
}

.hero-contact-info h3 {
    color: white;
    margin-bottom: 1rem;
    font-size: 1.2rem;
    font-weight: 600;
}

.hero-contact-links {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.hero-contact-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: white;
    font-weight: 500;
    transition: all 0.3s ease;
    padding: 0.5rem;
    border-radius: 5px;
}

.hero-contact-link:hover {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    transform: translateX(5px);
}

.hero-contact-link i {
    font-size: 1.1rem;
    width: 20px;
}

.btn {
    padding: 12px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-block;
    border: none;
    cursor: pointer;
}

.btn-primary {
    background: #2563eb;
    color: white;
}

.btn-primary:hover {
    background: #1d4ed8;
    transform: translateY(-2px);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background: white;
    color: #2563eb;
}

.profile-card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 2rem;
    text-align: center;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.profile-avatar {
    width: 140px;
    height: 140px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
    overflow: hidden;
    border: 4px solid rgba(255, 255, 255, 0.3);
}

.profile-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 50%;
}

.profile-card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

/* Section Styles */
.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: #1f2937;
}

/* Page Header */
.page-header {
    padding: 120px 0 60px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.page-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.page-subtitle {
    font-size: 1.25rem;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto;
}

.page-date {
    font-size: 1rem;
    opacity: 0.8;
    margin-top: 1rem;
}

/* Active Navigation Link */
.nav-link.active {
    color: #2563eb;
    font-weight: 600;
}

/* About Section */
.about {
    padding: 80px 0;
    background: #f8fafc;
}

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

.about-text p {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    color: #4b5563;
}

.contact-info {
    margin-top: 2rem;
    padding: 1.5rem;
    background: #f8f9fa;
    border-radius: 10px;
    border-left: 4px solid #2563eb;
}

.contact-info h3 {
    color: #333;
    margin-bottom: 1rem;
    font-size: 1.2rem;
    font-weight: 600;
}

.contact-links {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.contact-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: #2563eb;
    font-weight: 500;
    transition: all 0.3s ease;
    padding: 0.5rem;
    border-radius: 5px;
}

.contact-link:hover {
    background: #e3f2fd;
    color: #1976d2;
    transform: translateX(5px);
}

.contact-link i {
    font-size: 1.1rem;
    width: 20px;
}

.skills h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #1f2937;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.skill-tag {
    background: #2563eb;
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
}

/* Publications Section */
.publications {
    padding: 80px 0;
    background: #f8fafc;
}

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

.publication-item {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    margin-bottom: 2rem;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.publication-item h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: #1f2937;
}

.publication-authors {
    color: #6b7280;
    font-style: italic;
    margin-bottom: 0.5rem;
}

.publication-journal {
    color: #2563eb;
    font-weight: 500;
    margin-bottom: 1rem;
}

.publication-abstract {
    color: #4b5563;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.publication-links {
    display: flex;
    gap: 1rem;
}

.publication-link {
    color: #2563eb;
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9rem;
    transition: color 0.3s ease;
}

.publication-link:hover {
    color: #1d4ed8;
}

/* Formation Control Project */
.formation-control {
    padding: 80px 0;
    background: #f8fafc;
}

.project-header {
    text-align: center;
    margin-bottom: 3rem;
}

.project-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: #1f2937;
}

.project-description {
    font-size: 1.2rem;
    color: #4b5563;
    margin-bottom: 1rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.project-note {
    font-style: italic;
    color: #6b7280;
    margin-bottom: 2rem;
}

.paper-reference {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    margin-bottom: 3rem;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.paper-reference h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #1f2937;
}

.paper-details {
    padding: 1.5rem;
    background: #f8fafc;
    border-radius: 12px;
    border-left: 4px solid #2563eb;
}

.paper-authors {
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 0.5rem;
}

.paper-title {
    font-style: italic;
    color: #4b5563;
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.paper-conference {
    color: #6b7280;
    margin-bottom: 1rem;
}

.paper-doi {
    color: #2563eb;
    text-decoration: none;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: color 0.3s ease;
}

.paper-doi:hover {
    color: #1d4ed8;
}

.simulation-video {
    margin-bottom: 3rem;
}

.simulation-video h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #1f2937;
}

.video-container {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    margin-bottom: 1rem;
    text-align: center;
}

.video-container video {
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    max-width: 100%;
    height: auto;
    background: #000;
}

 .video-caption {
     text-align: center;
     color: #6b7280;
     font-style: italic;
 }

 /* Download Section */
 .download-section {
     margin-top: 3rem;
     text-align: center;
 }

 .download-section h3 {
     font-size: 1.5rem;
     margin-bottom: 1rem;
     color: #1f2937;
 }

 .download-box {
     background: #10b981;
     padding: 1.5rem;
     border-radius: 12px;
     box-shadow: 0 4px 20px rgba(16, 185, 129, 0.2);
     display: inline-block;
     transition: transform 0.3s ease, box-shadow 0.3s ease;
 }

 .download-box:hover {
     transform: translateY(-2px);
     box-shadow: 0 6px 25px rgba(16, 185, 129, 0.3);
 }

 .download-link {
     color: white;
     text-decoration: none;
     font-weight: 600;
     font-size: 1.1rem;
     display: flex;
     align-items: center;
     gap: 0.5rem;
     transition: color 0.3s ease;
 }

 .download-link:hover {
     color: #f0fdf4;
 }

 .download-link i {
     font-size: 1.2rem;
 }



/* ROS Simulations Section */
.ros-simulations {
    padding: 80px 0;
}

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

.ros-card {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.ros-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.15);
}

 .ros-image {
     height: 300px;
     background: white;
     display: flex;
     align-items: center;
     justify-content: center;
     overflow: hidden;
     border-radius: 12px 12px 0 0;
 }

 .ros-project-image {
     width: 100%;
     height: 100%;
     object-fit: contain;
     border-radius: 0;
     padding: 1rem;
 }

.ros-content {
    padding: 1.5rem;
}

.ros-content h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: #1f2937;
}

.ros-content p {
    color: #6b7280;
    margin-bottom: 1rem;
}

.ros-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.ros-links {
    display: flex;
    gap: 1rem;
}

.ros-link {
    color: #2563eb;
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9rem;
    transition: color 0.3s ease;
}

 .ros-link:hover {
     color: #1d4ed8;
 }

 /* Project Download Box */
 .project-download {
     margin-top: 1rem;
     text-align: center;
 }

 .project-download-link {
     background: #2563eb;
     color: white;
     text-decoration: none;
     font-weight: 600;
     font-size: 0.9rem;
     padding: 0.75rem 1.5rem;
     border-radius: 8px;
     display: inline-flex;
     align-items: center;
     gap: 0.5rem;
     transition: all 0.3s ease;
     box-shadow: 0 2px 10px rgba(37, 99, 235, 0.2);
 }

 .project-download-link:hover {
     background: #1d4ed8;
     transform: translateY(-2px);
     box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
     color: white;
 }

 .project-download-link i {
     font-size: 1rem;
 }

.tech-tag {
    background: #f3f4f6;
    color: #374151;
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 500;
}

/* Codes Section */
.codes {
    padding: 80px 0;
    background: #f8fafc;
}

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

.code-card {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.code-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.15);
}

.code-image {
    height: 200px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    color: white;
}

.code-content {
    padding: 1.5rem;
}

.code-content h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: #1f2937;
}

.code-content p {
    color: #6b7280;
    margin-bottom: 1rem;
}

.code-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.code-links {
    display: flex;
    gap: 1rem;
}

.code-link {
    color: #2563eb;
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9rem;
    transition: color 0.3s ease;
}

.code-link:hover {
    color: #1d4ed8;
}

/* CV Section */
.cv {
    padding: 80px 0;
}

.cv-content {
    max-width: 800px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: start;
}

.cv-download {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.cv-download h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #1f2937;
}

.cv-download p {
    color: #6b7280;
    margin-bottom: 2rem;
    line-height: 1.6;
}

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

.cv-highlights {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.cv-highlights h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #1f2937;
}

.cv-list {
    list-style: none;
    padding: 0;
}

.cv-list li {
    padding: 0.75rem 0;
    border-bottom: 1px solid #e5e7eb;
    color: #4b5563;
    position: relative;
    padding-left: 1.5rem;
}

.cv-list li:before {
    content: "✓";
    color: #2563eb;
    font-weight: bold;
    position: absolute;
    left: 0;
}

.cv-list li:last-child {
    border-bottom: none;
}

/* CV Details Section */
.cv-details {
    margin-top: 4rem;
}

.cv-section {
    margin-bottom: 3rem;
}

.cv-section h3 {
    font-size: 1.75rem;
    margin-bottom: 1.5rem;
    color: #1f2937;
    border-bottom: 2px solid #e5e7eb;
    padding-bottom: 0.5rem;
}

.cv-item {
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: white;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.cv-item h4 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: #1f2937;
}

.cv-institution {
    color: #2563eb;
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.cv-description {
    color: #6b7280;
    line-height: 1.6;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.skill-category {
    background: white;
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.skill-category h4 {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    color: #1f2937;
}

.skill-category ul {
    list-style: none;
    padding: 0;
}

.skill-category li {
    padding: 0.5rem 0;
    color: #4b5563;
    border-bottom: 1px solid #f3f4f6;
}

.skill-category li:last-child {
    border-bottom: none;
}

/* Footer */
.footer {
    background: #1f2937;
    color: white;
    text-align: center;
    padding: 2rem 0;
}

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

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.05);
        padding: 2rem 0;
    }

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

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

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

    .contact-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

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

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

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

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

    .container {
        padding: 0 15px;
    }
}

/* Smooth scrolling */
html {
    scroll-behavior: smooth;
}

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

.project-card {
    animation: fadeInUp 0.6s ease-out;
}

/* Loading animation */
.loading {
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.6s ease;
}

.loading.loaded {
    opacity: 1;
    transform: translateY(0);
}