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

:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --text-color: #1f2937;
    --text-light: #6b7280;
    --bg-color: #ffffff;
    --bg-light: #f9fafb;
    --border-color: #e5e7eb;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.1);
    --hero-gradient-start: #2563eb;
    --hero-gradient-end: #1e40af;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.7;
    color: var(--text-color);
    background-color: var(--bg-color);
}

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

/* Navigation */
.navbar {
    position: sticky;
    top: 0;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    z-index: 1000;
    box-shadow: var(--shadow);
}

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

.nav-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

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

.nav-menu a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-menu a:hover {
    color: var(--primary-color);
}

/* Hero Section */
.hero {
    padding: 5rem 0;
    background: linear-gradient(135deg, #2563eb 0%, #1e40af 100%);
    color: white;
}

.hero-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 4rem;
}

.hero-text {
    flex: 1;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    opacity: 0.95;
}

.hero-affiliation {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.social-links {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.social-links a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    padding: 0.75rem;
    background-color: rgba(255, 255, 255, 0.1);
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 12px;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.social-links a:hover {
    background-color: rgba(255, 255, 255, 0.25);
    border-color: white;
    transform: translateY(-3px);
}

.hero-image {
    flex: 0 0 300px;
}

.hero-image img {
    width: 100%;
    height: 300px;
    object-fit: cover;
    border-radius: 50%;
    border: 5px solid rgba(255, 255, 255, 0.3);
    box-shadow: var(--shadow-lg);
}

/* Scrolling Banner */
.scrolling-banner {
    background-color: var(--bg-light);
    padding: 2rem 0;
    overflow: hidden;
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

.scrolling-banner-track {
    display: flex;
    gap: 3rem;
    align-items: center;
    animation: scroll 30s linear infinite;
}

.scrolling-banner-track img {
    height: 50px;
    width: auto;
    object-fit: contain;
    filter: grayscale(100%);
    opacity: 0.6;
    transition: all 0.3s ease;
}

.scrolling-banner-track img:hover {
    filter: grayscale(0%);
    opacity: 1;
    transform: scale(1.1);
}

@keyframes scroll {
    0% {
        transform: translateX(0);
    }
    100% {
        transform: translateX(-50%);
    }
}

/* Section Styles */
.section {
    padding: 5rem 0;
}

.section:nth-child(even) {
    background-color: var(--bg-light);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.section-subtitle {
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 3rem;
}

/* About Section */
.about-content p {
    font-size: 1.125rem;
    line-height: 1.8;
    margin-bottom: 1.5rem;
    color: var(--text-light);
}

/* Featured Section */
.featured-grid {
    display: grid;
    gap: 3rem;
}

.featured-item {
    display: flex;
    gap: 2rem;
    padding: 2rem;
    background: white;
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.featured-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.featured-image {
    flex: 0 0 400px;
}

.featured-image img {
    width: 100%;
    height: 300px;
    object-fit: cover;
    border-radius: 8px;
}

.featured-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.featured-content h3 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.featured-content p {
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: 1.5rem;
}

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

.btn-link {
    display: inline-block;
    padding: 0.5rem 1.2rem;
    background-color: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: 6px;
    font-weight: 500;
    transition: background-color 0.3s ease;
}

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

/* Projects Section */
.filter-buttons {
    display: flex;
    gap: 1rem;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.7rem 1.5rem;
    border: 2px solid var(--border-color);
    background-color: white;
    color: var(--text-color);
    font-weight: 500;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.filter-btn:hover,
.filter-btn.active {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 2rem;
}

.project-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.project-image img {
    width: 100%;
    height: 250px;
    object-fit: cover;
}

.project-info {
    padding: 1.5rem;
}

.project-info h3 {
    font-size: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-color);
}

.project-description {
    color: var(--text-light);
    margin-bottom: 1rem;
}

.project-tags {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-bottom: 1rem;
}

.tag {
    padding: 0.25rem 0.75rem;
    background-color: var(--bg-light);
    color: var(--text-light);
    border-radius: 4px;
    font-size: 0.875rem;
}

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

.github-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 1.2rem;
    background-color: #24292e;
    color: white;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 500;
    font-size: 0.95rem;
    border: 2px solid #24292e;
    transition: all 0.3s ease;
}

.github-btn:hover {
    background-color: #0366d6;
    border-color: #0366d6;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(3, 102, 214, 0.3);
}

.github-btn svg {
    flex-shrink: 0;
}

/* Experience Section */
.timeline {
    position: relative;
    padding-left: 3rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 30px;
    top: 0;
    bottom: 0;
    width: 2px;
    background-color: var(--border-color);
}

.timeline-item {
    position: relative;
    display: flex;
    gap: 2rem;
    margin-bottom: 3rem;
}

.timeline-icon {
    position: absolute;
    left: -3rem;
    width: 60px;
    height: 60px;
    background: white;
    border: 3px solid var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.timeline-icon img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    padding: 5px;
}

.timeline-content {
    flex: 1;
    background: white;
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.timeline-content h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.timeline-content h4 {
    font-size: 1.2rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.timeline-date {
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: 1rem;
}

.timeline-description {
    list-style-position: inside;
    color: var(--text-light);
}

.timeline-description li {
    margin-bottom: 0.5rem;
}

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

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

.contact-email {
    display: inline-block;
    font-size: 1.5rem;
    color: var(--primary-color);
    text-decoration: none;
    margin-bottom: 2rem;
    font-weight: 600;
}

.contact-email:hover {
    text-decoration: underline;
}

.social-links-footer {
    display: flex;
    gap: 2rem;
    justify-content: center;
}

.social-links-footer a {
    color: var(--text-light);
    transition: color 0.3s ease;
}

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

/* Footer */
.footer {
    background-color: var(--text-color);
    color: white;
    padding: 2rem 0;
    text-align: center;
}

.footer p {
    opacity: 0.8;
}

/* Responsive Design */
@media (max-width: 968px) {
    .hero-content {
        flex-direction: column;
        text-align: center;
    }

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

    .hero-subtitle {
        font-size: 1.5rem;
    }

    .social-links {
        justify-content: center;
        flex-wrap: wrap;
    }

    .social-links a svg {
        width: 28px;
        height: 28px;
    }

    .scrolling-banner-track {
        gap: 2rem;
    }

    .scrolling-banner-track img {
        height: 40px;
    }

    .featured-item {
        flex-direction: column;
    }

    .featured-image {
        flex: 1;
    }

    .projects-grid {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    }

    .nav-menu {
        gap: 1rem;
    }
}

@media (max-width: 640px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

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

    .nav-menu {
        flex-wrap: wrap;
        gap: 0.5rem;
        font-size: 0.9rem;
    }

    .timeline {
        padding-left: 2rem;
    }

    .timeline-icon {
        left: -2rem;
        width: 40px;
        height: 40px;
    }

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

    .social-links a svg {
        width: 24px;
        height: 24px;
    }

    .social-links {
        gap: 1rem;
    }

    .scrolling-banner-track img {
        height: 35px;
    }

    .github-btn {
        font-size: 0.85rem;
        padding: 0.5rem 1rem;
    }

    .github-btn svg {
        width: 16px;
        height: 16px;
    }
}