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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #ffffff;
}

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

/* Navigation */
.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    transition: all 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo a {
    font-size: 1.5rem;
    font-weight: 700;
    color: #2563eb;
    text-decoration: none;
    transition: color 0.3s ease;
}

.nav-logo a:hover {
    color: #1d4ed8;
}

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

.nav-link {
    color: #64748b;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: #2563eb;
    transition: width 0.3s ease;
}

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

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

.bar {
    width: 25px;
    height: 3px;
    background: #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;
}

.hero-content {
    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: 1.5rem;
    font-weight: 400;
    margin-bottom: 1.5rem;
    opacity: 0.9;
}

.hero-description {
    font-size: 1.1rem;
    line-height: 1.7;
    margin-bottom: 2rem;
    opacity: 0.95;
}

.hero-link {
    color: #fbbf24;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.hero-link:hover {
    color: #f59e0b;
}

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

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 12px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.btn-primary {
    background: #fbbf24;
    color: #1f2937;
}

.btn-primary:hover {
    background: #f59e0b;
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(251, 191, 36, 0.3);
}

.btn-secondary {
    background: transparent;
    color: white;
    border-color: rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.5);
    transform: translateY(-2px);
}

.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.profile-image {
    max-width: 100%;
    height: auto;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2);
    transition: transform 0.3s ease;
}

.profile-image:hover {
    transform: scale(1.05);
}

/* Research Section */
.research {
    padding: 80px 0;
    background: #f8fafc;
}

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

.publications-content {
    max-width: 1000px;
    margin: 0 auto;
}

.publication-category {
    margin-bottom: 3rem;
}

.publication-category h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid #e2e8f0;
}

.publication-item {
    margin-bottom: 1.5rem;
    padding: 1.5rem;
    background: #f8fafc;
    border-radius: 8px;
    border-left: 4px solid #2563eb;
}

.publication-item p {
    margin: 0;
    line-height: 1.6;
    color: #475569;
}

.publication-link {
    color: #2563eb;
    text-decoration: none;
    font-weight: 500;
}

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

.publication-hidden {
    display: none;
}

.publication-category-hidden {
    display: none;
}

.view-more-btn {
    background: #2563eb;
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 1rem;
    display: block;
    margin-left: auto;
    margin-right: auto;
}

.view-more-btn:hover {
    background: #1d4ed8;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.view-more-btn:active {
    transform: translateY(0);
}

.view-more-categories-btn {
    background: #059669;
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    margin: 2rem auto;
    display: block;
    text-align: center;
}

.view-more-categories-btn:hover {
    background: #047857;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(5, 150, 105, 0.3);
}

.view-more-categories-btn:active {
    transform: translateY(0);
}

.github-link {
    color: #059669;
    text-decoration: none;
    font-weight: 500;
}

.github-link:hover {
    color: #047857;
    text-decoration: underline;
}

.award {
    background: #fbbf24;
    color: #1f2937;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-weight: 600;
    font-size: 0.875rem;
}

/* Presentations Section */
.presentations {
    padding: 80px 0;
    background: #f8fafc;
}

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

.presentation-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.presentation-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

.presentation-image {
    height: 200px;
    overflow: hidden;
}

.presentation-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.presentation-content {
    padding: 1.5rem;
}

.presentation-content h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 1rem;
}

.presentation-content p {
    color: #64748b;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

/* Projects Section */
.projects {
    padding: 80px 0;
    background: white;
}

.projects-content {
    max-width: 1200px;
    margin: 0 auto;
}

.project-category {
    margin-bottom: 4rem;
    padding: 2rem;
    background: #f8fafc;
    border-radius: 12px;
}

.project-category h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 1rem;
}

.project-category p {
    color: #64748b;
    margin-bottom: 2rem;
    font-size: 1.1rem;
}

.project-images {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.project-images img {
    width: 100%;
    height: 150px;
    object-fit: cover;
    border-radius: 8px;
    transition: transform 0.3s ease;
}

.project-images img:hover {
    transform: scale(1.05);
}

/* Projects Section - Optimized Pinterest Style */
.projects {
    padding: 80px 0;
    background: #f8fafc;
}

.projects-content {
    max-width: 1400px;
    margin: 0 auto;
}

/* Filter Buttons - Optimized */
.project-filters {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 3rem;
}

.filter-btn {
    background: white;
    border: 2px solid #e2e8f0;
    color: #64748b;
    padding: 0.75rem 1.5rem;
    border-radius: 50px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    user-select: none;
}

.filter-btn:hover {
    border-color: #2563eb;
    color: #2563eb;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.15);
}

.filter-btn.active {
    background: #2563eb;
    border-color: #2563eb;
    color: white;
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

/* Masonry Grid - Optimized */
.projects-masonry {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    align-items: start;
}

/* Project Cards - Optimized */
.project-card {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    cursor: pointer;
    will-change: transform;
    transform: translateZ(0); /* Force hardware acceleration */
}

.project-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.project-image {
    position: relative;
    overflow: hidden;
    height: 200px;
    background: #f8fafc;
    display: flex;
    align-items: center;
    justify-content: center;
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    object-position: center;
    transition: transform 0.3s ease;
    background: white;
    max-width: 100%;
    max-height: 100%;
}

.project-card:hover .project-image img {
    transform: scale(1.05);
}

/* Image format optimization */
.project-image img[src$=".gif"] {
    object-fit: cover;
}

/* Ensure proper scaling for different image types */
.project-image img[src$=".png"],
.project-image img[src$=".jpg"],
.project-image img[src$=".jpeg"] {
    object-fit: contain;
    object-position: center;
}

/* Special handling for very small images to prevent them from being too tiny */
.project-image img {
    min-width: 60px;
    min-height: 60px;
}

/* Ensure images maintain aspect ratio while fitting container */
.project-image {
    aspect-ratio: 16/9;
    min-height: 150px;
}

/* Override aspect ratio for very small screens to give more space */
@media (max-width: 480px) {
    .project-image {
        aspect-ratio: 4/3;
        min-height: 180px;
    }
}

.project-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(37, 99, 235, 0.9);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.project-card:hover .project-overlay {
    opacity: 1;
}

.project-overlay .project-link {
    color: white;
    font-size: 1.5rem;
    text-decoration: none;
    padding: 1rem;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.2);
    transition: all 0.3s ease;
}

.project-overlay .project-link:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
}

.project-content {
    padding: 1.5rem;
}

.project-content h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: #1e293b;
    margin: 0 0 0.75rem 0;
    line-height: 1.3;
}

.project-content p {
    color: #64748b;
    line-height: 1.6;
    margin: 0 0 1rem 0;
    font-size: 0.95rem;
}

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

.tag {
    background: #f1f5f9;
    color: #475569;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
    transition: all 0.3s ease;
}

.project-card:hover .tag {
    background: #dbeafe;
    color: #2563eb;
}

/* Animations - Optimized */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translate3d(0, 30px, 0);
    }
    to {
        opacity: 1;
        transform: translate3d(0, 0, 0);
    }
}

/* Responsive Design - Optimized */
@media (max-width: 768px) {
    .projects-masonry {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
        gap: 1.5rem;
    }
    
    .project-filters {
        gap: 0.5rem;
    }
    
    .filter-btn {
        padding: 0.5rem 1rem;
        font-size: 0.85rem;
    }
    
    .project-image {
        height: 200px;
        min-height: 180px;
    }
    
    .project-image img {
        object-fit: contain;
        object-position: center;
        padding: 10px;
    }
    
    .project-content {
        padding: 1.25rem;
    }
    
    .project-content h3 {
        font-size: 1.1rem;
    }
    
    .project-content p {
        font-size: 0.9rem;
    }
}

@media (max-width: 480px) {
    .projects-masonry {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .project-filters {
        justify-content: flex-start;
        overflow-x: auto;
        padding-bottom: 1rem;
        -webkit-overflow-scrolling: touch;
    }
    
    .filter-btn {
        white-space: nowrap;
        flex-shrink: 0;
        padding: 0.4rem 0.8rem;
        font-size: 0.8rem;
    }
    
    .project-image {
        height: 220px;
        min-height: 200px;
    }
    
    .project-image img {
        object-fit: contain;
        object-position: center;
        padding: 15px;
        max-width: 100%;
        max-height: 100%;
    }
    
    .project-content {
        padding: 1rem;
    }
    
    .project-content h3 {
        font-size: 1rem;
        margin-bottom: 0.5rem;
    }
    
    .project-content p {
        font-size: 0.85rem;
        margin-bottom: 0.75rem;
    }
    
    .tag {
        font-size: 0.75rem;
        padding: 0.2rem 0.6rem;
    }
}

@media (max-width: 360px) {
    .projects-masonry {
        gap: 0.75rem;
    }
    
    .project-image {
        height: 200px;
        min-height: 180px;
    }
    
    .project-image img {
        object-fit: contain;
        object-position: center;
        padding: 12px;
        max-width: 100%;
        max-height: 100%;
    }
    
    .project-content {
        padding: 0.75rem;
    }
    
    .project-content h3 {
        font-size: 0.95rem;
    }
    
    .project-content p {
        font-size: 0.8rem;
    }
}

/* Music Section */
.music {
    padding: 5rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

.music::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="music-pattern" x="0" y="0" width="20" height="20" patternUnits="userSpaceOnUse"><circle cx="10" cy="10" r="1" fill="rgba(255,255,255,0.1)"/></pattern></defs><rect width="100" height="100" fill="url(%23music-pattern)"/></svg>');
    opacity: 0.3;
    pointer-events: none;
}

.music .section-title,
.music .section-subtitle {
    color: white;
}

.music-content {
    max-width: 1200px;
    margin: 0 auto;
}

.music-section {
    margin-bottom: 3rem;
    background: rgba(255, 255, 255, 0.15);
    padding: 2.5rem;
    border-radius: 16px;
    backdrop-filter: blur(15px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    position: relative;
    z-index: 1;
    transition: all 0.3s ease;
}

.music-section:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.music-section h3 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 2rem;
    color: #fbbf24;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
    position: relative;
}

.music-section h3::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, #fbbf24, #f59e0b);
    border-radius: 2px;
}

.music-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.music-item {
    background: rgba(255, 255, 255, 0.15);
    padding: 2rem;
    border-radius: 16px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
    overflow: hidden;
}

.music-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

.music-item:hover::before {
    left: 100%;
}

.music-item:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
    background: rgba(255, 255, 255, 0.2);
}

.music-item h4 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: white;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
    position: relative;
    z-index: 2;
}

.music-icon {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, #ff6b6b 0%, #4ecdc4 50%, #45b7d1 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.2);
    transition: all 0.4s ease;
    position: relative;
    z-index: 2;
}

.music-icon:hover {
    transform: scale(1.15) rotate(5deg);
    box-shadow: 0 12px 35px rgba(0, 0, 0, 0.3);
    background: linear-gradient(135deg, #ff8a80 0%, #80cbc4 50%, #81d4fa 100%);
}

.music-icon i {
    font-size: 1.8rem;
    color: white;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

/* YouTube Preview Styles */
.youtube-preview {
    position: relative;
    width: 100%;
    max-width: 300px;
    margin: 1rem auto;
    border-radius: 12px;
    overflow: hidden;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    aspect-ratio: 16/9;
}

.youtube-preview:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.3);
}

.youtube-thumbnail {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    transition: all 0.3s ease;
}

.youtube-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: all 0.3s ease;
    color: white;
}

.youtube-preview:hover .youtube-overlay {
    opacity: 1;
}

.youtube-overlay i {
    font-size: 2.5rem;
    color: #ff0000;
    margin-bottom: 0.5rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.5);
}

.youtube-overlay span {
    font-size: 0.9rem;
    font-weight: 600;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.5);
    text-align: center;
}

/* Mobile Responsive YouTube Previews */
@media (max-width: 768px) {
    .youtube-preview {
        max-width: 280px;
        margin: 0.75rem auto;
        border-radius: 8px;
    }
    
    .youtube-overlay i {
        font-size: 2rem;
        margin-bottom: 0.25rem;
    }
    
    .youtube-overlay span {
        font-size: 0.8rem;
    }
}

@media (max-width: 480px) {
    .youtube-preview {
        max-width: 100%;
        margin: 0.5rem 0;
        border-radius: 6px;
    }
    
    .youtube-overlay i {
        font-size: 1.8rem;
    }
    
    .youtube-overlay span {
        font-size: 0.75rem;
    }
}

.music-item .btn {
    margin-right: 0.75rem;
    margin-bottom: 0.75rem;
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: white;
    font-weight: 600;
    transition: all 0.3s ease;
    position: relative;
    z-index: 2;
}

.music-item .btn:hover {
    background: rgba(255, 255, 255, 0.3);
    border-color: rgba(255, 255, 255, 0.5);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.youtube-section {
    text-align: center;
    padding: 3rem;
    background: rgba(255, 255, 255, 0.15);
    border-radius: 16px;
    backdrop-filter: blur(15px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    position: relative;
    z-index: 1;
    transition: all 0.3s ease;
}

.youtube-section:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.youtube-section p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.95;
    font-weight: 500;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
}

/* NetEase Music Section */
.netease-section {
    text-align: center;
    padding: 3rem;
    background: rgba(255, 255, 255, 0.15);
    border-radius: 16px;
    backdrop-filter: blur(15px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    position: relative;
    z-index: 1;
    transition: all 0.3s ease;
}

.netease-section:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.netease-section p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.95;
    font-weight: 500;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: #1e293b;
    margin-bottom: 1rem;
}

.section-subtitle {
    font-size: 1.2rem;
    color: #64748b;
    max-width: 600px;
    margin: 0 auto;
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.research-card {
    background: white;
    border-radius: 16px;
    padding: 2rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
    border: 1px solid #e2e8f0;
}

.research-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

.research-image {
    margin-bottom: 1.5rem;
    text-align: center;
}

.research-image img {
    max-width: 100%;
    height: auto;
    border-radius: 12px;
}

.research-content h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 1rem;
}

.research-content p {
    color: #64748b;
    line-height: 1.6;
}

/* Footer */
.footer {
    background: #1e293b;
    color: white;
    padding: 4rem 0 2rem;
}

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

.footer-section h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #f1f5f9;
}

.footer-section p {
    color: #94a3b8;
    margin-bottom: 0.5rem;
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.footer-links a {
    color: #94a3b8;
    text-decoration: none;
    transition: color 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.footer-links a:hover {
    color: #f1f5f9;
}

.footer-bottom {
    border-top: 1px solid #334155;
    padding-top: 2rem;
    text-align: center;
    color: #94a3b8;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: white;
        flex-direction: column;
        justify-content: flex-start;
        align-items: center;
        padding-top: 2rem;
        transition: left 0.3s ease;
        box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    }

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

    .nav-toggle {
        display: flex;
    }

    .nav-toggle.active .bar:nth-child(2) {
        opacity: 0;
    }

    .nav-toggle.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .nav-toggle.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    .hero-content {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }

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

    .hero-subtitle {
        font-size: 1.25rem;
    }

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

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

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

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

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

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .hero {
        padding: 100px 0 60px;
    }

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

    .btn {
        padding: 10px 20px;
        font-size: 0.9rem;
    }

    .research {
        padding: 60px 0;
    }

    .research-card {
        padding: 1.5rem;
    }
}

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

.hero-content,
.research-card {
    animation: fadeInUp 0.6s ease-out;
}

/* Custom scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
    background: #c1c1c1;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #a8a8a8;
}