/* ===== CSS Variables & Theming ===== */
:root {
    --bg: #0a0a0f;
    --bg-surface: #111118;
    --bg-surface-hover: #1a1a24;
    --text: #e4e4e7;
    --text-secondary: #a1a1aa;
    --accent: #818cf8;
    --accent-hover: #6366f1;
    --accent-glow: rgba(129, 140, 248, 0.15);
    --border: rgba(255, 255, 255, 0.06);
    --border-hover: rgba(255, 255, 255, 0.12);
    --particle-color: 129, 140, 248;
    --nav-bg: rgba(10, 10, 15, 0.8);
    --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
    --tag-bg: rgba(129, 140, 248, 0.1);
    --tag-text: #a5b4fc;
    --badge-production-bg: rgba(34, 197, 94, 0.1);
    --badge-production-text: #4ade80;
    --badge-research-bg: rgba(129, 140, 248, 0.1);
    --badge-research-text: #a5b4fc;
}

[data-theme="light"] {
    --bg: #f0f7f0;
    --bg-surface: #ffffff;
    --bg-surface-hover: #f0fdf0;
    --text: #18181b;
    --text-secondary: #52525b;
    --accent: #16a34a;
    --accent-hover: #15803d;
    --accent-glow: rgba(22, 163, 74, 0.1);
    --border: rgba(0, 0, 0, 0.08);
    --border-hover: rgba(0, 0, 0, 0.15);
    --particle-color: 22, 163, 74;
    --nav-bg: rgba(240, 247, 240, 0.85);
    --shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
    --tag-bg: rgba(22, 163, 74, 0.08);
    --tag-text: #15803d;
    --badge-production-bg: rgba(22, 163, 74, 0.1);
    --badge-production-text: #15803d;
    --badge-research-bg: rgba(99, 102, 241, 0.08);
    --badge-research-text: #4f46e5;
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    transition: background 0.3s ease, color 0.3s ease;
    overflow-x: hidden;
}

::selection {
    background: var(--accent);
    color: #fff;
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: var(--accent-hover);
}

strong {
    color: var(--text);
    font-weight: 600;
}

/* ===== Canvas ===== */
#agent-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
}

/* ===== Layout ===== */
.container {
    max-width: 1080px;
    margin: 0 auto;
    padding: 0 24px;
}

.section {
    position: relative;
    z-index: 1;
    padding: 100px 0;
}

/* ===== Navigation ===== */
#navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: var(--nav-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    transition: background 0.3s, border-color 0.3s, transform 0.3s;
}

#navbar.hidden {
    transform: translateY(-100%);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.nav-logo {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.5px;
}

.nav-logo .dot {
    color: var(--accent);
}

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-links a {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color 0.2s;
    position: relative;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--accent);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width 0.3s;
}

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

.nav-actions {
    display: flex;
    align-items: center;
    gap: 8px;
}

.icon-btn {
    background: none;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    cursor: pointer;
    padding: 8px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.icon-btn:hover {
    color: var(--accent);
    border-color: var(--accent);
    background: var(--accent-glow);
}

[data-theme="dark"] .icon-sun { display: none; }
[data-theme="dark"] .icon-moon { display: block; }
[data-theme="light"] .icon-sun { display: block; }
[data-theme="light"] .icon-moon { display: none; }

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
}

.hamburger span {
    display: block;
    width: 20px;
    height: 2px;
    background: var(--text-secondary);
    border-radius: 2px;
    transition: all 0.3s;
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ===== Hero ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 80px;
    padding-bottom: 40px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 14px;
    border-radius: 100px;
    border: 1px solid var(--border);
    background: var(--bg-surface);
    margin-bottom: 24px;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.pulse {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: #4ade80;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; box-shadow: 0 0 0 0 rgba(74, 222, 128, 0.4); }
    50% { opacity: 0.8; box-shadow: 0 0 0 8px rgba(74, 222, 128, 0); }
}

.hero-label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--accent);
    letter-spacing: 2px;
    text-transform: uppercase;
    margin-bottom: 12px;
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: -1.5px;
    margin-bottom: 16px;
}

.hero-subtitle {
    font-size: clamp(1rem, 2vw, 1.15rem);
    color: var(--text-secondary);
    max-width: 640px;
    line-height: 1.7;
    margin-bottom: 32px;
}

.hero-subtitle strong {
    color: var(--accent);
    font-weight: 600;
}

.hero-links {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

/* ===== Hero Highlights ===== */
.hero-highlights {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
    margin-top: 48px;
    margin-bottom: 32px;
}

.highlight-card {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 20px;
    transition: all 0.3s;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.highlight-card:hover {
    border-color: var(--accent);
    background: var(--bg-surface-hover);
    box-shadow: 0 0 20px var(--accent-glow);
    transform: translateY(-2px);
}

.highlight-top {
    display: flex;
    align-items: baseline;
    gap: 6px;
    margin-bottom: 2px;
}

.highlight-number {
    font-family: 'JetBrains Mono', monospace;
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent);
    line-height: 1;
}

.highlight-unit {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.highlight-label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text);
    line-height: 1.3;
}

.highlight-context {
    font-size: 0.75rem;
    color: var(--text-secondary);
    line-height: 1.4;
}

/* ===== Hero Tech Strip ===== */
.hero-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    padding-top: 8px;
}

.hero-tech span {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    padding: 4px 12px;
    border-radius: 100px;
    background: var(--tag-bg);
    color: var(--tag-text);
    font-weight: 500;
    border: 1px solid var(--border);
    transition: all 0.2s;
}

.hero-tech span:hover {
    border-color: var(--accent);
    background: var(--accent-glow);
    color: var(--accent);
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    border-radius: 8px;
    font-size: 0.875rem;
    font-weight: 500;
    font-family: inherit;
    transition: all 0.2s;
    cursor: pointer;
    border: 1px solid transparent;
}

.btn-primary {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
}

.btn-primary:hover {
    background: var(--accent-hover);
    border-color: var(--accent-hover);
    color: #fff;
    box-shadow: 0 4px 16px var(--accent-glow);
}

.btn-outline {
    background: transparent;
    color: var(--text-secondary);
    border-color: var(--border);
}

.btn-outline:hover {
    color: var(--accent);
    border-color: var(--accent);
    background: var(--accent-glow);
}

.btn-lg {
    padding: 14px 28px;
    font-size: 1rem;
}

/* ===== Section Title ===== */
.section-title {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 48px;
    letter-spacing: -0.5px;
}

.section-number {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1rem;
    font-weight: 500;
    color: var(--accent);
    margin-right: 8px;
}

/* ===== About ===== */
.about-content {
    display: grid;
    gap: 40px;
}

.about-text p {
    color: var(--text-secondary);
    margin-bottom: 16px;
    font-size: 1rem;
    line-height: 1.8;
}

.about-text p:last-child {
    margin-bottom: 0;
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.stat-card {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 24px;
    text-align: center;
    transition: all 0.3s;
}

.stat-card:hover {
    border-color: var(--border-hover);
    background: var(--bg-surface-hover);
}

.stat-number {
    display: block;
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--accent);
    margin-bottom: 4px;
    font-family: 'JetBrains Mono', monospace;
}

.stat-label {
    font-size: 0.8rem;
    color: var(--text-secondary);
    font-weight: 500;
}

/* ===== Experience Timeline ===== */
.timeline {
    position: relative;
    padding-left: 32px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 8px;
    bottom: 8px;
    width: 2px;
    background: var(--border);
}

.timeline-item {
    position: relative;
    margin-bottom: 48px;
}

.timeline-item:last-child {
    margin-bottom: 0;
}

.timeline-marker {
    position: absolute;
    left: -37px;
    top: 8px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--accent);
    border: 3px solid var(--bg);
    box-shadow: 0 0 0 2px var(--accent);
}

.timeline-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 16px;
}

.timeline-header h3 {
    font-size: 1.25rem;
    font-weight: 600;
}

.timeline-company {
    display: block;
    font-size: 0.9rem;
    color: var(--accent);
    font-weight: 500;
    margin-top: 2px;
}

.timeline-date {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    color: var(--text-secondary);
    white-space: nowrap;
    padding-top: 4px;
}

.timeline-details {
    list-style: none;
}

.timeline-details li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 12px;
    color: var(--text-secondary);
    font-size: 0.925rem;
    line-height: 1.7;
}

.timeline-details li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-size: 0.9rem;
}

.timeline-details li:last-child {
    margin-bottom: 0;
}

/* ===== Projects ===== */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.project-card {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 28px;
    transition: all 0.3s;
    position: relative;
}

.project-card:hover {
    border-color: var(--border-hover);
    background: var(--bg-surface-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
    color: var(--accent);
}

.project-badge {
    font-size: 0.7rem;
    font-weight: 600;
    padding: 3px 10px;
    border-radius: 100px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.project-badge.production {
    background: var(--badge-production-bg);
    color: var(--badge-production-text);
}

.project-badge.research {
    background: var(--badge-research-bg);
    color: var(--badge-research-text);
}

.project-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 10px;
}

.project-card p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.7;
    margin-bottom: 16px;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.project-tags span {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.7rem;
    padding: 3px 10px;
    border-radius: 4px;
    background: var(--tag-bg);
    color: var(--tag-text);
}

.project-link {
    position: absolute;
    top: 28px;
    right: 28px;
    color: var(--text-secondary);
    transition: color 0.2s;
}

.project-link:hover {
    color: var(--accent);
}

/* ===== Skills ===== */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.skill-group {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 24px;
    transition: all 0.3s;
}

.skill-group:hover {
    border-color: var(--border-hover);
}

.skill-group h3 {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--accent);
    margin-bottom: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.skill-tags span {
    font-size: 0.8rem;
    padding: 4px 12px;
    border-radius: 6px;
    background: var(--tag-bg);
    color: var(--tag-text);
    font-weight: 500;
    transition: all 0.2s;
}

.skill-tags span:hover {
    background: var(--accent);
    color: #fff;
}

/* ===== Open Source ===== */
.opensource-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.repo-card {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 24px;
    transition: all 0.3s;
    display: flex;
    flex-direction: column;
    color: var(--text);
}

.repo-card:hover {
    border-color: var(--border-hover);
    background: var(--bg-surface-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
    color: var(--text);
}

.repo-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
    color: var(--accent);
}

.repo-card h3 {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.repo-card p {
    color: var(--text-secondary);
    font-size: 0.85rem;
    line-height: 1.6;
    flex: 1;
    margin-bottom: 12px;
}

.repo-lang {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.lang-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}

.lang-dot.python { background: #3572A5; }
.lang-dot.html { background: #e34c26; }

/* ===== Publication ===== */
.publication-card {
    display: flex;
    gap: 24px;
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 32px;
    transition: all 0.3s;
}

.publication-card:hover {
    border-color: var(--border-hover);
}

.pub-icon {
    flex-shrink: 0;
    width: 56px;
    height: 56px;
    border-radius: 12px;
    background: var(--accent-glow);
    color: var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
}

.pub-content h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 6px;
}

.pub-venue {
    font-size: 0.875rem;
    color: var(--accent);
    font-weight: 500;
    margin-bottom: 8px;
}

.pub-detail {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 12px;
}

.pub-doi {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    color: var(--accent);
    font-weight: 500;
}

.pub-doi:hover {
    text-decoration: underline;
}

/* ===== Education ===== */
.education-card {
    display: flex;
    gap: 24px;
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 32px;
    transition: all 0.3s;
}

.education-card:hover {
    border-color: var(--border-hover);
}

.edu-icon {
    flex-shrink: 0;
    width: 56px;
    height: 56px;
    border-radius: 12px;
    background: var(--accent-glow);
    color: var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
}

.edu-content h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 6px;
}

.edu-degree {
    font-size: 0.9rem;
    color: var(--accent);
    font-weight: 500;
    margin-bottom: 4px;
}

.edu-date {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* ===== Footer ===== */
.footer {
    text-align: center;
    border-top: 1px solid var(--border);
}

.footer-cta {
    margin-bottom: 48px;
}

.footer-cta h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 16px;
    letter-spacing: -0.5px;
}

.footer-cta p {
    color: var(--text-secondary);
    max-width: 500px;
    margin: 0 auto 28px;
    font-size: 1rem;
    line-height: 1.7;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 24px;
    margin-bottom: 32px;
}

.footer-links a {
    color: var(--text-secondary);
    transition: all 0.2s;
    padding: 8px;
    border-radius: 8px;
}

.footer-links a:hover {
    color: var(--accent);
    background: var(--accent-glow);
}

.footer-bottom {
    padding-top: 24px;
    border-top: 1px solid var(--border);
}

.footer-bottom p {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-bottom: 4px;
}

.footer-note {
    font-size: 0.75rem !important;
    opacity: 0.6;
}

/* ===== Scroll to Top ===== */
.scroll-top-btn {
    position: fixed;
    bottom: 24px;
    right: 24px;
    z-index: 99;
    width: 44px;
    height: 44px;
    border-radius: 10px;
    background: var(--bg-surface);
    border: 1px solid var(--border);
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all 0.3s;
}

.scroll-top-btn.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.scroll-top-btn:hover {
    color: var(--accent);
    border-color: var(--accent);
    background: var(--accent-glow);
}

/* ===== Animations ===== */
.fade-in {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .projects-grid,
    .opensource-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .skills-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .section {
        padding: 72px 0;
    }

    .nav-links {
        position: fixed;
        top: 64px;
        left: 0;
        right: 0;
        background: var(--nav-bg);
        backdrop-filter: blur(16px);
        -webkit-backdrop-filter: blur(16px);
        flex-direction: column;
        align-items: center;
        gap: 0;
        padding: 16px 0;
        border-bottom: 1px solid var(--border);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s;
    }

    .nav-links.open {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-links a {
        padding: 12px 24px;
        width: 100%;
        text-align: center;
    }

    .nav-links a::after {
        display: none;
    }

    .hamburger {
        display: flex;
    }

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

    .hero-subtitle br {
        display: none;
    }

    .hero-highlights {
        grid-template-columns: repeat(2, 1fr);
    }

    .about-stats {
        grid-template-columns: repeat(2, 1fr);
    }

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

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

    .timeline {
        padding-left: 24px;
    }

    .timeline-marker {
        left: -29px;
        width: 10px;
        height: 10px;
    }

    .timeline-header {
        flex-direction: column;
    }

    .publication-card,
    .education-card {
        flex-direction: column;
        gap: 16px;
    }

    .footer-cta h2 {
        font-size: 1.5rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .hero-links {
        flex-direction: column;
    }

    .hero-links .btn {
        justify-content: center;
    }

    .hero-highlights {
        grid-template-columns: 1fr;
    }

    .highlight-number {
        font-size: 1.5rem;
    }

    .about-stats {
        grid-template-columns: 1fr 1fr;
    }

    .stat-card {
        padding: 16px;
    }

    .stat-number {
        font-size: 1.5rem;
    }
}