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

:root {
    /* Theme palette (purple) */
    --ai2-pink: #6366f1;
    --primary-color: var(--ai2-pink);
    --text-primary: #111111;
    --text-secondary: #2b2b2b;
    --background: #ffffff;
    --surface: #f9fafb;
    --border: #e5e7eb;
    --hover-bg: #eef2ff;
    --accent-hover: var(--ai2-pink);
    --gradient-start: var(--ai2-pink);
    --gradient-end: var(--ai2-pink);
    --hl-1: rgba(99, 102, 241, 0.14);
    --hl-2: rgba(168, 85, 247, 0.14);
    --hl-strong: rgba(99, 102, 241, 0.22);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--background);
    padding-top: 60px;
}

/* Navigation */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.nav-container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    justify-content: center;
    gap: 2rem;
}

.nav-link {
    display: block;
    padding: 1rem 0;
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9375rem;
    transition: color 0.2s ease;
    border-bottom: 2px solid transparent;
}

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

/* Container */
.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
}

/* Header */
header {
    text-align: center;
    padding: 3rem 0 4rem;
    border-bottom: 1px solid var(--border);
    margin-bottom: 3rem;
    scroll-margin-top: 80px;
}

h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    letter-spacing: -0.025em;
}

.subtitle {
    font-size: 1.3rem;
    color: var(--text-secondary);
    font-weight: 400;
    line-height: 1.5;
}

.location {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
    margin-bottom: 2rem;
}

.header-links {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 0.75rem;
    flex-wrap: nowrap;
    margin-top: 2rem;
}

.header-links .link-button {
    flex: none;
    width: auto;
    min-width: auto;
    max-width: none;
    display: inline-flex;
    white-space: nowrap;
    padding: 0.5rem 0.75rem;
}

/* Sections */
section {
    margin-bottom: 4rem;
    scroll-margin-top: 80px;
}

h2 {
    font-size: 1.875rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-size: 1.0625rem;
    line-height: 1.75;
}

/* About Section */
.about {
    text-align: center;
}
.about p {
    max-width: 750px;
    margin-left: auto;
    margin-right: auto;
}

/* Work Section */
.work-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.work-item {
    padding: 1.5rem;
    background-color: var(--surface);
    border-radius: 0.5rem;
    border: 1px solid var(--border);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.work-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.work-item h3 {
    color: var(--primary-color);
}

.work-item p {
    margin-bottom: 0;
    font-size: 0.9375rem;
}

/* Links Section */
.links-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-top: 2rem;
}

.link-button {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    padding: 1rem 1.5rem;
    background-color: var(--surface);
    border: 2px solid var(--border);
    border-radius: 0.5rem;
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.2s ease;
}

.link-button:hover {
    border-color: var(--primary-color);
    background-color: var(--hover-bg);
    color: var(--primary-color);
    transform: translateY(-2px);
}

.link-button svg {
    flex-shrink: 0;
}

/* Projects Section */
.project-section {
    margin-bottom: 3rem;
    padding: 2rem;
    background-color: var(--surface);
    border-radius: 0.5rem;
    border-left: 3px solid var(--primary-color);
    scroll-margin-top: 80px;
}

.project-section h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.project-section p {
    margin-bottom: 1rem;
}

.project-section ul {
    margin-left: 1.5rem;
    margin-top: 1rem;
}

.project-section li {
    margin-bottom: 0.75rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.project-section li strong {
    color: var(--text-primary);
}

/* Publications Section */
.publication-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.publication-item {
    padding: 1rem;
    background-color: var(--surface);
    border-radius: 0.5rem;
    border-left: 3px solid var(--primary-color);
    margin-bottom: 1rem;
}

.publication-item h3 {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
}

.publication-meta {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-style: italic;
    margin-bottom: 0.5rem;
}

.publication-item > p:not(.publication-meta) {
    font-size: 0.9375rem;
    margin-bottom: 0.5rem;
}

.publication-item strong {
    text-decoration: underline;
    text-decoration-color: var(--primary-color);
    text-decoration-thickness: 2px;
    text-underline-offset: 2px;
    /* Fallback for older browsers */
    border-bottom: 2px solid var(--primary-color);
    text-decoration: none;
}

.publication-link {
    display: inline-flex;
    align-items: center;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9375rem;
    transition: color 0.2s ease;
}

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

/* Ai2 link (pink underline + subtle pink highlight) */
.ai2-link {
    color: var(--ai2-pink);
    text-decoration: none;
    background-image: linear-gradient(var(--ai2-pink), var(--ai2-pink));
    background-size: 100% 1px;
    background-repeat: no-repeat;
    background-position: 0 100%;
    transition: color 0.2s ease;
}

.ai2-link:hover {
    color: var(--ai2-pink);
}

/* Publication badges */
.badge {
    display: inline-block;
    padding: 0.125rem 0.375rem;
    border-radius: 999px;
    font-size: 0.75rem;
    font-weight: 600;
    line-height: 1;
    vertical-align: middle;
    margin-left: 0.35rem;
}

.badge.spotlight {
    background: rgba(99, 102, 241, 0.12);
    color: var(--ai2-pink);
    border: 1px solid rgba(99, 102, 241, 0.3);
}

/* Footer */
footer {
    text-align: center;
    padding: 3rem 0 2rem;
    border-top: 1px solid var(--border);
    margin-top: 4rem;
}

footer p {
    font-size: 0.9375rem;
    color: var(--text-secondary);
}

/* Responsive Design */
@media (max-width: 768px) {
    body {
        padding-top: 56px;
    }

    .nav-container {
        gap: 1rem;
        padding: 0 1rem;
    }

    .nav-link {
        font-size: 0.875rem;
        padding: 0.875rem 0;
    }

    .container {
        padding: 1.5rem 1rem;
    }

    header {
        padding: 2rem 0 3rem;
    }

    h1 {
        font-size: 2.25rem;
    }

    .subtitle {
        font-size: 1.125rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    section {
        margin-bottom: 3rem;
    }

    .work-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .links-grid {
        grid-template-columns: 1fr;
        gap: 0.75rem;
    }

    .project-section {
        padding: 1.5rem;
    }
}

@media (max-width: 480px) {
    .nav-container {
        gap: 0.5rem;
    }

    .nav-link {
        font-size: 0.8125rem;
        padding: 0.75rem 0;
    }

    h1 {
        font-size: 2rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .work-item,
    .publication-item,
    .project-section {
        padding: 1.25rem;
    }
}

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

/* Selection Color */
::selection {
    background-color: rgba(99, 102, 241, 0.2);
    color: var(--text-primary);
}

/* Location in header */
.location {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
}

/* Experience Section */
.experience-item {
    margin-bottom: 3rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border);
}

.experience-item:last-child {
    border-bottom: none;
}

.experience-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 0.75rem;
    gap: 2rem;
}

.experience-header h3 {
    font-size: 1.25rem;
    margin-bottom: 0.25rem;
    color: var(--text-primary);
}

.company {
    font-size: 1rem;
    color: var(--primary-color);
    font-weight: 500;
    margin: 0;
}

.experience-meta {
    text-align: right;
    flex-shrink: 0;
}

.date {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    margin: 0;
}

.location-text {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin: 0.25rem 0 0 0;
}

.advisor {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    font-style: italic;
    margin-bottom: 1rem;
}

.experience-item ul {
    margin-left: 1.5rem;
    margin-top: 0.75rem;
}

.experience-item li {
    margin-bottom: 0.75rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Research Areas Grid */
.research-areas {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.research-area {
    padding: 1.5rem;
    background-color: var(--surface);
    border-radius: 0.5rem;
    border: 1px solid var(--border);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.research-area:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.research-area h3 {
    color: var(--primary-color);
    margin-bottom: 0.75rem;
}

.research-area p {
    margin: 0;
    font-size: 0.9375rem;
}

/* Authors in publications */
.authors {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

/* Projects Section */
.project-list {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.project-item {
    padding: 1.5rem;
    background-color: var(--surface);
    border-radius: 0.5rem;
    border-left: 3px solid var(--primary-color);
}

.project-item h3 {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
}

.tech-stack {
    font-size: 0.875rem;
    color: var(--primary-color);
    font-weight: 500;
    margin-bottom: 0.75rem;
}

.project-item p:not(.tech-stack) {
    font-size: 0.9375rem;
    margin-bottom: 0.75rem;
}

.project-link {
    display: inline-flex;
    align-items: center;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9375rem;
    transition: color 0.2s ease;
}

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

/* Education Section */
.education-item {
    padding: 1.5rem;
    background-color: var(--surface);
    border-radius: 0.5rem;
    border: 1px solid var(--border);
}

.education-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 2rem;
}

.education-header h3 {
    font-size: 1.25rem;
    margin-bottom: 0.25rem;
    color: var(--text-primary);
}

.degree {
    font-size: 1rem;
    color: var(--text-secondary);
    margin: 0;
}

.education-meta {
    text-align: right;
    flex-shrink: 0;
}

.gpa {
    font-size: 0.9375rem;
    color: var(--primary-color);
    font-weight: 500;
    margin: 0.25rem 0 0 0;
}

/* Responsive adjustments for new sections */
@media (max-width: 768px) {
    .experience-header,
    .education-header {
        flex-direction: column;
        gap: 0.5rem;
    }

    .experience-meta,
    .education-meta {
        text-align: left;
    }

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

/* Compact layout tweaks */
/* Work section: convert to slim one-line rows with small icons */
.work-grid {
    grid-template-columns: 1fr;
    gap: 0.5rem;
}

.work-item {
    display: grid;
    grid-template-columns: 160px 1fr;
    gap: 1rem;
    padding: 0.5rem 0;
    background-color: transparent;
    border: none;
    border-bottom: 1px solid var(--border);
    border-radius: 0;
    transition: color 0.2s ease, border-color 0.2s ease;
    align-items: start;
}

/* Fallback for older browsers */
@supports not (display: grid) {
    .work-item {
        display: flex;
        align-items: flex-start;
    }
    
    .work-item h3 {
        width: 160px;
        flex-shrink: 0;
    }
    
    .work-item p {
        flex: 1;
    }
}

.work-item:hover {
    transform: none;
    box-shadow: none;
    border-color: var(--primary-color);
}

.work-item h3 {
    margin: 0;
    font-size: 1rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
}

.work-item h3::before {
    content: none;
    display: none;
    margin: 0;
}

.work-item p {
    margin: 0;
    font-size: 0.9375rem;
    color: var(--text-secondary);
    white-space: normal;
    overflow: visible;
    text-overflow: unset;
    line-height: 1.5;
}

/* Tighten global spacing */
header {
    padding: 2rem 0 2.5rem;
    margin-bottom: 2.5rem;
}

section {
    margin-bottom: 3rem;
}

/* Simplify Projects section styling */
.project-section {
    margin-bottom: 1.5rem;
    padding: 1rem 0;
    background-color: transparent;
    border-radius: 0;
    border-left: none;
    border-bottom: 1px solid var(--border);
}

.project-section h3 {
    color: var(--text-primary);
    margin-bottom: 0.25rem;
    font-size: 1.125rem;
}

.project-section p {
    margin-bottom: 0.5rem;
}

.project-section ul {
    margin-left: 1rem;
    margin-top: 0.5rem;
}

.project-section li {
    margin-bottom: 0.5rem;
}

/* Slightly smaller link buttons */
.link-button {
    padding: 0.75rem 1rem;
}

/* Skip link */
.skip-link {
    position: absolute;
    left: -9999px;
    top: auto;
    width: 1px;
    height: 1px;
    overflow: hidden;
}

.skip-link:focus {
    left: 1rem;
    top: 1rem;
    width: auto;
    height: auto;
    background: var(--surface);
    color: var(--text-primary);
    border: 2px solid var(--primary-color);
    padding: 0.5rem 0.75rem;
    z-index: 1100;
}

/* Header CTAs */
.header-ctas {
    display: flex;
    justify-content: center;
    gap: 0.75rem;
    margin-top: 1rem;
    flex-wrap: wrap;
}

.cta-button {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 0.875rem;
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    background: var(--surface);
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
}

.cta-button:hover {
    border-color: var(--primary-color);
    background: var(--hover-bg);
    color: var(--primary-color);
}

.cta-button.secondary {
    background: var(--surface);
    color: var(--text-primary);
    border-color: var(--border);
}

/* Skills */
.skills-list {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.5rem 1rem;
}

.skills-list li {
    color: var(--text-secondary);
}

/* Compact project rows */
.project-list {
    list-style: none;
    padding-left: 0;
}

.project-list li {
    display: flex;
    align-items: baseline;
    gap: 0.5rem;
}

.project-list a {
    color: var(--text-primary);
    text-decoration: none;
    border-bottom: 1px solid transparent;
}

.project-list a:hover {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

/* Dark mode */
@media (prefers-color-scheme: dark) {
    :root {
        --background: #0b0f1a;
        --surface: #0f172a;
        --text-primary: #e5e7eb;
        --text-secondary: #9ca3af;
        --border: #1f2a44;
        --hover-bg: #121a2e;
    }

    .nav {
        background-color: rgba(10, 15, 26, 0.7);
        border-bottom-color: var(--border);
    }
}

/* Minimal Tech theme enhancements */
/* Gradient text for main heading */
h1 {
    background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

/* Subtle gradient stripe under header and ensure stacking */
header { position: relative; }
header::after {
    content: none;
    position: absolute;
    left: 0; right: 0; bottom: -1px; height: 3px;
    background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
    opacity: 0.25;
    border-radius: 2px;
}

/* Monospace accent for subheadings */
h3 {
    letter-spacing: -0.01em;
}

/* Subtle background texture for depth */
body::before {
    content: "";
    position: fixed;
    inset: 0;
    z-index: -1;
    pointer-events: none;
    background-image: radial-gradient(circle at 1px 1px, rgba(17, 24, 39, 0.04) 1px, transparent 1px);
    background-size: 16px 16px;
}

/* Animated link underline for project items */
.project-list a {
    text-decoration: none;
    background-image: linear-gradient(currentColor, currentColor);
    background-size: 0% 1px;
    background-repeat: no-repeat;
    background-position: 0 100%;
    transition: color 0.2s ease, background-size 0.2s ease;
}
.project-list a:hover {
    color: var(--primary-color);
    background-size: 100% 1px;
}

/* Animated underline for publication links */
.publication-link {
    position: relative;
    background-image: linear-gradient(currentColor, currentColor);
    background-size: 0% 1px;
    background-repeat: no-repeat;
    background-position: 0 100%;
    transition: color 0.2s ease, background-size 0.2s ease;
}
.publication-link:hover {
    color: var(--accent-hover);
    background-size: 100% 1px;
}

/* Enhanced CTA hover micro-interaction */
.cta-button:hover {
    transform: translateY(-1px);
}

/* Dark mode gradient tuning and texture */
@media (prefers-color-scheme: dark) {
    :root {
        --gradient-start: var(--ai2-pink);
        --gradient-end: var(--ai2-pink);
    }
    body::before {
        background-image: radial-gradient(circle at 1px 1px, rgba(148, 163, 184, 0.06) 1px, transparent 1px);
    }
}

/* Anchor target highlight */
section:target, .project-section:target {
    animation: targetFlash 0.8s ease-out;
}
@keyframes targetFlash {
    0% {
        background-color: rgba(99, 102, 241, 0.08);
        box-shadow: 0 0 0 2px rgba(99, 102, 241, 0.25) inset;
    }
    100% {
        background-color: transparent;
        box-shadow: none;
    }
}

/* Highlight utilities */
:root {
    --hl-1: rgba(99, 102, 241, 0.14);
    --hl-2: rgba(168, 85, 247, 0.14);
    --hl-strong: rgba(99, 102, 241, 0.22);
}

@media (prefers-color-scheme: dark) {
    :root {
        --hl-1: rgba(129, 140, 248, 0.18);
        --hl-2: rgba(167, 139, 250, 0.18);
        --hl-strong: rgba(129, 140, 248, 0.28);
    }
}

.hl {
    box-shadow: inset 0 -0.32em 0 var(--hl-1);
    border-radius: 2px;
    padding: 0 .04em;
}

.hl-strong {
    box-shadow: inset 0 -0.42em 0 var(--hl-strong);
    border-radius: 2px;
    padding: 0 .05em;
}

.hl-grad {
    background-image: linear-gradient(to bottom, transparent 72%, var(--hl-1) 0, var(--hl-2) 96%);
    -webkit-box-decoration-break: clone;
    box-decoration-break: clone;
    border-radius: 2px;
    padding: 0 .05em;
}