/* Reset and Base Styles */
:root {
    --color-primary: #4338ca;
    --color-primary-dark: #1e1b4b;
    --color-primary-mid: #312e81;
    --color-primary-light: #6366f1;
    --color-accent: #5b21b6;
    --color-hero-text: #f8fafc;
    --color-surface: #f9fafb;
    --color-text: #4b5563;
    --color-heading: #1f2937;
    --color-muted: #6b7280;
    --color-teal: #0d9488;
    --shadow-sm: 0 4px 6px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 8px 16px rgba(0, 0, 0, 0.1);
    --radius-md: 12px;
    --radius-lg: 16px;
}

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

html {
    scroll-behavior: smooth;
}

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;
    transition: all 0.3s ease;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.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: var(--color-primary);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

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

.nav-link {
    color: #374151;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

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

.nav-link.active {
    color: var(--color-primary);
    font-weight: 600;
}

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

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

/* Mouse clicks get the underline treatment instead of the default square outline,
   while :focus-visible keeps a real ring for keyboard users. */
.nav-link:focus,
.nav-logo a:focus,
.nav-toggle:focus {
    outline: none;
}

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

.nav-link:focus-visible,
.nav-logo a:focus-visible,
.nav-toggle:focus-visible {
    outline: 2px solid var(--color-primary-light);
    outline-offset: 6px;
    border-radius: 6px;
}

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

.bar {
    width: 25px;
    height: 3px;
    background: #374151;
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, var(--color-primary-dark) 0%, var(--color-primary-mid) 55%, var(--color-primary) 100%);
    color: var(--color-hero-text);
    position: relative;
    overflow: hidden;
}

.hero::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="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="50" cy="50" r="1" fill="white" opacity="0.1"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.1;
}

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

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

.highlight {
    color: #fbbf24;
}

.hero-subtitle {
    font-size: 1.1rem;
    font-weight: 500;
    margin-bottom: 1.5rem;
    opacity: 0.95;
    line-height: 1.55;
    max-width: 38rem;
    letter-spacing: 0.01em;
}

.hero-description {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    line-height: 1.7;
}

.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: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.hero .btn-primary {
    background: white;
    color: var(--color-primary);
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.12);
}

.hero .btn-primary:hover {
    background: #f8fafc;
    color: var(--color-primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.18);
}

.btn-primary {
    background: var(--color-primary);
    color: white;
}

.btn-primary:hover {
    background: var(--color-primary-mid);
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(30, 27, 75, 0.35);
}

.hero .btn-secondary {
    background: rgba(255, 255, 255, 0.08);
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.9);
}

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

.profile-card {
    display: flex;
    justify-content: center;
    align-items: center;
}

.profile-image {
    width: 300px;
    height: 300px;
    border-radius: 50%;
    overflow: hidden;
    border: 4px solid rgba(255, 255, 255, 0.2);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

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

/* Section Styles */
section {
    padding: 80px 0;
}

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

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: var(--color-primary-light);
    border-radius: 2px;
}

/* About Section */
.about {
    background: #f9fafb;
}

.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-text p {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    color: #4b5563;
    line-height: 1.7;
}

.about-stats {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.stat {
    text-align: center;
    padding: 1.5rem;
    background: white;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    transition: transform 0.3s ease;
    border-top: 3px solid var(--color-primary);
}

.stat:hover {
    transform: translateY(-5px);
}

.stat h3 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: 0.5rem;
}

.stat p {
    color: #6b7280;
    font-weight: 500;
}

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

.skill-category {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease;
}

.skill-category:hover {
    transform: translateY(-5px);
}

.skill-category h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--color-heading);
}

.skill-category--genai {
    border-top: 3px solid var(--color-primary);
}

.skill-category--tools {
    border-top: 3px solid var(--color-accent);
}

.skill-category--llm {
    border-top: 3px solid var(--color-accent);
}

.skill-category--llm .skill-item {
    background: #f5f3ff;
    color: #6d28d9;
    border: 1px solid #ddd6fe;
}

.skill-category--llm .skill-item:hover {
    background: var(--color-accent);
    color: white;
    border-color: var(--color-accent);
}

.skill-items {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.skill-item {
    background: #f3f4f6;
    color: #374151;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.3s ease;
}

.skill-category--genai .skill-item {
    background: linear-gradient(135deg, var(--color-primary-mid), var(--color-primary-light));
    color: white;
}

.skill-category--tools .skill-item {
    background: #eef2ff;
    color: var(--color-primary);
    border: 1px solid #c7d2fe;
}

.skill-item:hover {
    transform: translateY(-2px);
}

.skill-category--genai .skill-item:hover {
    box-shadow: 0 4px 12px rgba(79, 70, 229, 0.35);
}

.skill-category--tools .skill-item:hover {
    background: var(--color-primary);
    color: white;
    border-color: var(--color-primary);
}

.skill-category:not(.skill-category--genai):not(.skill-category--tools):not(.skill-category--llm) .skill-item:hover {
    background: #e5e7eb;
}

.research-publications {
    margin-bottom: 3rem;
}

/* Experience Section */
.experience {
    background: #f9fafb;
}

.timeline {
    position: relative;
    max-width: 860px;
    margin: 0 auto;
}

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

.timeline-item {
    position: relative;
    margin-bottom: 2.5rem;
    padding-left: 4rem;
    width: 100%;
}

.timeline-marker {
    position: absolute;
    left: 20px;
    top: 0;
    width: 20px;
    height: 20px;
    background: var(--color-primary);
    border-radius: 50%;
    z-index: 1;
}

.timeline-content {
    background: white;
    padding: 2.5rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease;
    border-left: 4px solid var(--color-primary);
}

.timeline-content:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
}

.timeline-content h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 0.5rem;
    line-height: 1.3;
}

.timeline-content h4 {
    color: var(--color-primary);
    font-weight: 600;
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.timeline-date {
    color: #6b7280;
    font-size: 0.95rem;
    font-weight: 500;
    margin-bottom: 1.5rem;
    display: block;
    padding: 0.5rem 0;
    border-bottom: 1px solid #e5e7eb;
}

.timeline-content p {
    color: #4b5563;
    margin-bottom: 1.25rem;
    line-height: 1.75;
    font-size: 1rem;
}

.timeline-content p:last-of-type {
    margin-bottom: 1.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 2px solid #f3f4f6;
}

.timeline-content ul {
    list-style: none;
    padding-left: 0;
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 2px solid #f3f4f6;
}

.timeline-content li {
    color: #4b5563;
    margin-bottom: 0.75rem;
    position: relative;
    padding-left: 1.75rem;
    line-height: 1.7;
    font-size: 0.95rem;
}

.timeline-content li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--color-primary);
    font-weight: bold;
    font-size: 1.1rem;
}

/* Publications Section */
.publications-description {
    text-align: center;
    max-width: 800px;
    margin: 0 auto 3rem;
}

.publications-description p {
    font-size: 1.1rem;
    color: #4b5563;
    line-height: 1.7;
    font-style: italic;
}

.publications-grid {
    display: grid;
    gap: 2rem;
}

.publication-item {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease;
    border-left: 4px solid var(--color-primary);
}

.publication-item:hover {
    transform: translateY(-5px);
}

.publication-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
    gap: 1rem;
}

.publication-header h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: #1f2937;
    flex: 1;
}

.publication-year {
    background: var(--color-primary-light);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.9rem;
    font-weight: 500;
    white-space: nowrap;
}

.publication-description {
    color: #4b5563;
    margin-bottom: 1.5rem;
    line-height: 1.6;
    font-size: 1rem;
}

.publication-authors {
    color: #6b7280;
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.publication-venue {
    color: #4b5563;
    margin-bottom: 1.5rem;
    font-style: italic;
}

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

.publication-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.publication-link:hover {
    color: var(--color-primary-mid);
}

/* Projects Section */
.projects {
    background: #f9fafb;
}

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

.projects-category:last-child {
    margin-bottom: 0;
}

.projects-category-header {
    display: flex;
    align-items: center;
    gap: 1.25rem;
    background: white;
    padding: 1.5rem 1.75rem;
    border-radius: 16px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    margin-bottom: 1.5rem;
    border-left: 5px solid var(--color-primary);
}

.projects-category--se .projects-category-header {
    border-left-color: #0d9488;
}

.projects-category-icon {
    width: 52px;
    height: 52px;
    border-radius: 14px;
    background: linear-gradient(135deg, var(--color-primary-mid), var(--color-primary-light));
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.35rem;
    flex-shrink: 0;
}

.projects-category--se .projects-category-icon {
    background: linear-gradient(135deg, #0d9488, #0891b2);
}

.projects-category-text {
    flex: 1;
}

.projects-category-text h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 0.25rem;
}

.projects-category-text p {
    color: #6b7280;
    font-size: 0.95rem;
}

.projects-count {
    background: #eef2ff;
    color: var(--color-primary);
    font-weight: 700;
    font-size: 0.9rem;
    padding: 0.4rem 0.85rem;
    border-radius: 999px;
    flex-shrink: 0;
}

.projects-category--se .projects-count {
    background: #ccfbf1;
    color: #0f766e;
}

.projects-showcase {
    display: grid;
    grid-template-columns: minmax(240px, 320px) 1fr;
    gap: 1.5rem;
    align-items: start;
}

.projects-nav {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    position: sticky;
    top: 90px;
}

.project-nav-item {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.2rem;
    width: 100%;
    text-align: left;
    background: white;
    border: 2px solid transparent;
    border-radius: 12px;
    padding: 1rem 1.1rem;
    cursor: pointer;
    transition: all 0.25s ease;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.04);
}

.project-nav-item:hover {
    border-color: #e0e7ff;
    transform: translateX(4px);
}

.project-nav-item.active {
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
    border-color: var(--color-primary);
    box-shadow: 0 8px 20px rgba(67, 56, 202, 0.25);
    transform: translateX(6px);
}

.projects-category--se .project-nav-item.active {
    background: linear-gradient(135deg, #0d9488, #14b8a6);
    border-color: #0d9488;
    box-shadow: 0 8px 20px rgba(13, 148, 136, 0.25);
}

.project-nav-title {
    font-size: 0.98rem;
    font-weight: 600;
    color: #1f2937;
}

.project-nav-item.active .project-nav-title,
.project-nav-item.active .project-nav-meta {
    color: white;
}

.project-nav-meta {
    font-size: 0.8rem;
    color: #6b7280;
    font-weight: 500;
}

.projects-detail {
    background: white;
    border-radius: 16px;
    padding: 2rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    border: 1px solid #e5e7eb;
    min-height: 320px;
}

.project-detail-panel {
    display: none;
    animation: projectFadeIn 0.35s ease;
}

.project-detail-panel.active {
    display: block;
}

@keyframes projectFadeIn {
    from {
        opacity: 0;
        transform: translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.project-detail-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 1.25rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid #f3f4f6;
}

.project-detail-header h4 {
    font-size: 1.35rem;
    font-weight: 700;
    color: #1f2937;
    line-height: 1.35;
}

.project-year {
    background: var(--color-primary-light);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.9rem;
    font-weight: 500;
    white-space: nowrap;
    flex-shrink: 0;
}

.projects-category--se .project-year {
    background: #0d9488;
}

.project-description {
    color: #4b5563;
    margin-bottom: 1.5rem;
    line-height: 1.7;
    font-size: 1rem;
}

.project-capstone-label {
    margin: -0.75rem 0 1rem;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--color-muted);
    font-style: italic;
}

.project-highlights {
    margin: -0.5rem 0 1.25rem;
    padding-left: 1.25rem;
    color: #4b5563;
}

.project-highlights li {
    margin-bottom: 0.5rem;
    line-height: 1.65;
    font-size: 0.95rem;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.tech-tag {
    background: #e5e7eb;
    color: #374151;
    padding: 0.25rem 0.75rem;
    border-radius: 16px;
    font-size: 0.85rem;
    font-weight: 500;
}

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

.project-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    padding: 0.5rem 1rem;
    border: 2px solid var(--color-primary);
    border-radius: 20px;
    font-size: 0.9rem;
}

.project-link:hover {
    background: var(--color-primary-light);
    color: white;
}

.projects-category--se .project-link {
    color: #0d9488;
    border-color: #0d9488;
}

.projects-category--se .project-link:hover {
    background: #0d9488;
    color: white;
}

.projects-category--learning .projects-category-header {
    border-left-color: var(--color-accent);
}

.projects-category--learning .projects-category-icon {
    background: linear-gradient(135deg, var(--color-accent), #6d28d9);
}

.projects-category--learning .projects-count {
    background: #f5f3ff;
    color: var(--color-accent);
}

.projects-category--learning .project-nav-item.active {
    background: linear-gradient(135deg, var(--color-accent), #6d28d9);
    border-color: var(--color-accent);
    box-shadow: 0 8px 20px rgba(91, 33, 182, 0.25);
}

.projects-category--learning .project-year {
    background: #f5f3ff;
    color: var(--color-accent);
}

.projects-category--learning .project-link {
    color: var(--color-accent);
    border-color: var(--color-accent);
}

.projects-category--learning .project-link:hover {
    background: var(--color-accent);
    color: white;
}

/* Achievements Section */
.achievements {
    background: #ffffff;
}

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

.achievement-item {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    text-align: center;
    transition: transform 0.3s ease;
    border-left: 4px solid var(--color-primary);
}

.achievement-item:hover {
    transform: translateY(-5px);
}

.achievement-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--color-primary-mid), var(--color-primary-light));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    color: white;
    font-size: 2rem;
}

.achievement-item h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 1rem;
}

.achievement-item p {
    color: #4b5563;
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.achievement-links {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.achievement-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    padding: 0.5rem 1rem;
    border: 2px solid var(--color-primary);
    border-radius: 20px;
    font-size: 0.9rem;
}

.achievement-link:hover {
    color: var(--color-primary-mid);
    background: var(--color-primary-light);
    color: white;
}

/* Research Section */
.research {
    background: #f9fafb;
}

.research-section-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 2rem;
    text-align: center;
}

.research-experience {
    margin-bottom: 4rem;
}

.research-timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

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

.research-timeline-item {
    position: relative;
    margin-bottom: 2rem;
    padding-left: 4rem;
}

.research-timeline-marker {
    position: absolute;
    left: 20px;
    top: 0;
    width: 20px;
    height: 20px;
    background: var(--color-primary-light);
    border-radius: 50%;
    z-index: 1;
}

.research-timeline-content {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease;
}

.research-timeline-content:hover {
    transform: translateY(-5px);
}

.research-timeline-content h4 {
    font-size: 1.25rem;
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 0.5rem;
}

.research-timeline-content h5 {
    color: var(--color-primary);
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.research-timeline-date {
    color: #6b7280;
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    display: block;
}

.research-status {
    display: inline-block;
    background: #fef3c7;
    color: #92400e;
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 1rem;
    border: 1px solid #fde68a;
}

.research-timeline-content p {
    color: #4b5563;
    margin-bottom: 1rem;
    line-height: 1.6;
}

.research-timeline-content ul {
    list-style: none;
    padding-left: 0;
}

.research-timeline-content li {
    color: #4b5563;
    margin-bottom: 0.5rem;
    position: relative;
    padding-left: 1.5rem;
}

.research-timeline-content li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--color-primary);
    font-weight: bold;
}

.research-timeline-content a {
    color: var(--color-primary);
    font-weight: 500;
    text-decoration: none;
    transition: color 0.3s ease;
}

.research-timeline-content a:hover {
    color: var(--color-primary-mid);
    text-decoration: underline;
}

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

.research-item {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    text-align: center;
    transition: transform 0.3s ease;
}

.research-item:hover {
    transform: translateY(-5px);
}

.research-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--color-primary-mid), var(--color-primary-light));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    color: white;
    font-size: 2rem;
}

.research-item h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 1rem;
}

.research-item p {
    color: #4b5563;
    line-height: 1.6;
    margin-bottom: 1rem;
}

.research-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1rem;
}

.research-tag {
    background: #f3f4f6;
    color: var(--color-primary);
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 500;
    border: 1px solid #e5e7eb;
    transition: all 0.3s ease;
}

.research-tag:hover {
    background: var(--color-primary-light);
    color: white;
    transform: translateY(-1px);
}

/* Contact Section */
.contact {
    background: linear-gradient(180deg, #ffffff 0%, var(--color-surface) 100%);
}

.contact-content {
    max-width: 640px;
    margin: 0 auto;
    text-align: center;
}

.contact-info {
    background: white;
    padding: 2.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid #e5e7eb;
}

.contact-info h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 1rem;
}

.contact-info p {
    color: #4b5563;
    margin-bottom: 2rem;
    line-height: 1.6;
}

.contact-note {
    background: #f3f4f6;
    padding: 1rem;
    border-radius: 8px;
    border-left: 4px solid var(--color-primary);
    font-size: 0.9rem;
    margin-bottom: 2rem;
}

.contact-note a {
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 500;
}

.contact-note a:hover {
    text-decoration: underline;
}

.contact-details {
    margin-bottom: 2rem;
}

.contact-item {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 1rem;
    color: #4b5563;
}

.contact-item i {
    color: var(--color-primary);
    width: 20px;
}

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

.contact-item a:hover {
    color: var(--color-primary-mid);
    text-decoration: underline;
}

.social-links {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.social-link {
    width: 50px;
    height: 50px;
    background: var(--color-primary-light);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    transition: all 0.3s ease;
    font-size: 1.5rem;
}

.social-link:hover {
    background: var(--color-primary-dark);
    transform: translateY(-3px);
}

.social-link img {
    width: 28px;
    height: 28px;
}

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

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1.25rem;
}

.footer-links a {
    color: #d1d5db;
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: white;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .nav-menu {
        gap: 1rem;
    }

    .nav-link {
        font-size: 0.875rem;
    }
}

@media (max-width: 768px) {
    .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;
    }

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

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

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

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

    .about-stats {
        flex-direction: row;
        justify-content: space-around;
    }

    .timeline::before {
        left: 20px;
    }

    .timeline-item {
        width: 100%;
        left: 0 !important;
        padding-left: 3rem;
        padding-right: 0;
    }

    .timeline-marker {
        left: 10px !important;
        right: auto !important;
    }

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

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

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

    .hero-subtitle {
        font-size: 0.95rem;
        max-width: 100%;
    }

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

    .projects-nav {
        position: static;
        flex-direction: row;
        overflow-x: auto;
        padding-bottom: 0.5rem;
        gap: 0.75rem;
        scrollbar-width: thin;
    }

    .project-nav-item {
        min-width: 180px;
        flex-shrink: 0;
    }

    .project-nav-item:hover,
    .project-nav-item.active {
        transform: none;
    }

    .projects-category-header {
        flex-wrap: wrap;
    }

    .projects-category-text h3 {
        font-size: 1.25rem;
    }

    .llm-dev-header {
        flex-direction: column;
        align-items: flex-start;
    }
}

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

    .hero-title {
        font-size: 1.8rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }

    .about-stats {
        flex-direction: column;
        gap: 1rem;
    }

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

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

    .publication-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }

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

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

.fade-in-up {
    animation: fadeInUp 0.6s ease-out;
}

/* Focus styling for the remaining interactive elements, matching the navbar:
   no ring on mouse click, rounded ring on keyboard focus. */
.btn:focus,
.social-link:focus,
.project-link:focus,
.publication-link:focus,
.achievement-link:focus,
.project-nav-item:focus {
    outline: none;
}

.btn:focus-visible,
.social-link:focus-visible,
.project-link:focus-visible,
.publication-link:focus-visible,
.achievement-link:focus-visible,
.project-nav-item:focus-visible {
    outline: 2px solid var(--color-primary-light);
    outline-offset: 4px;
    border-radius: 8px;
}

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

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

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

::-webkit-scrollbar-thumb {
    background: var(--color-primary-light);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-primary-mid);
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}