:root {
    --bg-color: #f8fafc;
    --card-bg: rgba(255, 255, 255, 0.9);
    --card-border: rgba(0, 0, 0, 0.08);
    --card-hover-bg: rgba(255, 255, 255, 1);
    --card-hover-border: rgba(0, 0, 0, 0.15);
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --accent: #2563eb;
    --accent-glow: rgba(37, 99, 235, 0.3);
    --font-main: 'Inter', sans-serif;
    --gap: 16px;
    --radius: 20px;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-main);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    overflow-x: hidden;
    padding: 2rem;
}

/* Background Canvas */
#generative-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    pointer-events: none;
}

/* Container */
.bento-container {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(4, auto);
    gap: var(--gap);
    max-width: 1200px;
    width: 100%;
    margin-top: 2rem;
    margin-bottom: 2rem;
}

/* Card Base Styles */
.bento-item {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--radius);
    padding: 2rem;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    overflow: hidden;
    position: relative;
}

.bento-item:hover {
    background: var(--card-hover-bg);
    border-color: var(--card-hover-border);
    transform: translateY(-2px);
    box-shadow: 0 10px 30px -10px rgba(0,0,0,0.5);
}

.bento-item h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.bento-item p {
    font-size: 0.95rem;
    line-height: 1.5;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

a {
    text-decoration: none;
    color: inherit;
}

/* Buttons and Links */
.btn, .btn-primary, .btn-outline {
    display: inline-block;
    padding: 0.6rem 1.2rem;
    border-radius: 999px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.2s;
    text-align: center;
    width: fit-content;
}

.btn {
    background: rgba(0, 0, 0, 0.05);
    color: var(--text-primary);
    border: 1px solid var(--card-border);
}
.btn:hover {
    background: rgba(0, 0, 0, 0.1);
    border-color: var(--card-hover-border);
}

.btn-primary {
    background: var(--text-primary);
    color: white;
}
.btn-primary:hover {
    background: #334155;
    transform: scale(1.05);
}

.btn-outline {
    border: 1px solid var(--card-border);
    color: var(--text-secondary);
}
.btn-outline:hover {
    border-color: var(--text-primary);
    color: var(--text-primary);
}

.link {
    color: var(--text-secondary);
    font-size: 0.9rem;
    border-bottom: 1px solid transparent;
}
.link:hover {
    color: var(--text-primary);
    border-bottom-color: var(--text-primary);
}


/* Specific Item Layouts */

/* Hero: Spans 2 cols, 2 rows */
.hero {
    grid-column: span 2;
    grid-row: span 2;
    background: radial-gradient(circle at top right, rgba(59, 130, 246, 0.1), transparent 60%), var(--card-bg);
    justify-content: center;
}

.hero h1 {
    font-size: 3rem;
    font-weight: 700;
    letter-spacing: -0.05em;
    margin-bottom: 0.5rem;
    background: linear-gradient(to right, #1e293b, #3b82f6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero h2 {
    font-size: 1.1rem;
    color: var(--text-secondary);
    font-weight: 400;
    margin-bottom: 1.5rem;
}

.tagline {
    font-size: 1.1rem;
    color: var(--text-secondary);
}

.highlight {
    color: var(--accent);
    font-weight: 500;
}

.affiliation {
    margin-top: 2rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
    opacity: 0.7;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Bio: 2 cols */
.bio {
    grid-column: span 2;
}

/* Research: 1 col, 2 rows */
.research {
    grid-column: span 1;
    grid-row: span 2;
}

/* Gen AI: 1 col, 2 rows */
.gen-ai {
    grid-column: span 1;
    grid-row: span 2;
    border: 1px solid rgba(59, 130, 246, 0.2);
    box-shadow: inset 0 0 20px rgba(59, 130, 246, 0.05);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
}
.gen-ai .icon-header {
    margin-bottom: 1rem;
    color: var(--accent);
}

/* Teaching: 1 col */
.teaching {
    grid-column: span 1;
}

/* CV: 1 col */
.cv {
    grid-column: span 1;
}

/* Socials: Small squares */
.social-twitter, .social-bluesky, .social-github, .social-scholar {
    grid-column: span 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0;
}
.social-twitter a, .social-bluesky a, .social-github a, .social-scholar a {
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 1.5rem;
}
.social-twitter svg, .social-bluesky svg, .social-github svg, .social-scholar svg {
    width: 32px;
    height: 32px;
    transition: transform 0.3s ease;
}

.social-twitter:hover svg, .social-bluesky:hover svg, .social-github:hover svg, .social-scholar:hover svg {
    transform: scale(1.1) rotate(5deg);
}

.social-bluesky:hover svg {
    color: #0085ff;
}

.social-scholar:hover svg {
    color: #4285f4;
}

/* Responsive */
@media (max-width: 900px) {
    .bento-container {
        grid-template-columns: repeat(2, 1fr);
    }
    .hero {
        grid-column: span 2;
    }
    .bio {
        grid-column: span 2;
    }
}

@media (max-width: 600px) {
    .bento-container {
        grid-template-columns: 1fr;
        display: flex;
        flex-direction: column;
    }
    .hero, .bio, .research, .gen-ai, .teaching, .cv, .social-twitter, .social-bluesky, .social-github, .social-scholar {
        grid-column: span 1;
        grid-row: auto; /* Reset row spans */
    }
    .hero { order: 1; }
    .bio { order: 2; }
    .research { order: 3; }
    .teaching { order: 4; }
    .cv { order: 5; }
    .gen-ai { order: 6; }
    .social-twitter { order: 7; }
    .social-bluesky { order: 8; }
    .social-github { order: 9; }
    .social-scholar { order: 10; }
    .hero h1 {
        font-size: 2.5rem;
    }
}

/* Profile Picture Styles */
.hero {
    flex-direction: row;
    align-items: center;
    gap: 2rem;
}

.profile-pic {
    width: 140px;
    height: 140px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid var(--accent);
    box-shadow: 0 0 25px rgba(59, 130, 246, 0.4);
    flex-shrink: 0;
}

/* Chat Widget */
.chat-widget {
    position: fixed;
    bottom: 1.5rem;
    right: 1.5rem;
    width: 300px;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.1);
    z-index: 100;
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.chat-widget.closed {
    height: 44px;
    width: 170px;
    cursor: pointer;
}

.chat-widget.closed:hover {
    background: var(--card-hover-bg);
}

.chat-header {
    height: 44px;
    padding: 0 1rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--card-border);
    user-select: none;
}

.chat-header span {
    font-weight: 600;
    font-size: 0.8rem;
    color: var(--text-primary);
}

#chat-toggle {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 4px;
    transition: color 0.2s;
}

#chat-toggle:hover {
    color: var(--accent);
}

.chat-widget.closed #chat-toggle {
    transform: rotate(0deg);
}

/* Chat Body (Hidden when closed) */
.chat-body {
    height: 300px;
    display: flex;
    flex-direction: column;
    opacity: 1;
    transition: opacity 0.2s;
}

.chat-widget.closed .chat-body {
    opacity: 0;
    pointer-events: none;
}

.chat-messages {
    flex: 1;
    padding: 0.75rem;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.msg {
    padding: 0.6rem 0.8rem;
    border-radius: 10px;
    font-size: 0.8rem;
    line-height: 1.4;
    max-width: 85%;
}

.msg.bot {
    background: rgba(0, 0, 0, 0.04);
    color: var(--text-secondary);
    align-self: flex-start;
    border-bottom-left-radius: 2px;
}

.msg.user {
    background: var(--accent);
    color: white;
    align-self: flex-end;
    border-bottom-right-radius: 2px;
}

.chat-input-area {
    padding: 0.6rem;
    border-top: 1px solid var(--card-border);
    display: flex;
    gap: 0.4rem;
}

.chat-input-area input {
    flex: 1;
    background: rgba(0, 0, 0, 0.03);
    border: 1px solid var(--card-border);
    border-radius: 16px;
    padding: 0.5rem 0.8rem;
    color: var(--text-primary);
    font-family: var(--font-main);
    font-size: 0.8rem;
    outline: none;
}

.chat-input-area input:focus {
    border-color: var(--accent);
}

.chat-input-area button {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    color: var(--text-primary);
    width: 30px;
    height: 30px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    transition: all 0.2s;
}

.chat-input-area button:hover {
    background: var(--accent);
    border-color: var(--accent);
}

/* Mobile Adjustment for Profile Pic in Hero */
@media (max-width: 600px) {
    .hero {
        flex-direction: column;
        text-align: center;
    }
    .profile-pic {
        width: 120px;
        height: 120px;
    }
    .chat-widget {
        right: 1rem;
        bottom: 1rem;
        width: calc(100% - 2rem);
    }
}

/* Agentic Thinking Stages */
.thinking-container {
    padding: 0.8rem 1rem;
    background: rgba(0, 0, 0, 0.03);
    border-radius: 12px;
    border-bottom-left-radius: 2px;
    max-width: 85%;
    align-self: flex-start;
}

.thinking-stage {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
    padding: 0.3rem 0;
    opacity: 0.5;
    transition: opacity 0.3s ease;
}

.thinking-stage.active {
    opacity: 1;
    color: var(--accent);
}

.thinking-stage.complete {
    opacity: 0.7;
    color: #22c55e;
}

.thinking-stage .icon {
    width: 14px;
    height: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.thinking-stage .spinner {
    width: 12px;
    height: 12px;
    border: 2px solid transparent;
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.thinking-stage .checkmark {
    color: #22c55e;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Streaming response */
.msg.bot.streaming {
    background: linear-gradient(90deg, rgba(0,0,0,0.03) 0%, rgba(59,130,246,0.1) 50%, rgba(0,0,0,0.03) 100%);
    background-size: 200% 100%;
    animation: shimmer 1.5s ease-in-out infinite;
}

@keyframes shimmer {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

/* Response formatting */
.msg.bot a {
    color: var(--accent);
    text-decoration: underline;
    text-underline-offset: 2px;
}

.msg.bot a:hover {
    color: #60a5fa;
}

.msg.bot strong {
    color: var(--text-primary);
}

.msg.bot ul, .msg.bot ol {
    margin: 0.5rem 0;
    padding-left: 1.2rem;
}

.msg.bot li {
    margin: 0.3rem 0;
}

/* Citations */
.msg.bot .citation {
    color: var(--accent);
    font-size: 0.8em;
    font-weight: 600;
    text-decoration: none;
    background: rgba(59, 130, 246, 0.15);
    padding: 0.1em 0.3em;
    border-radius: 4px;
    margin: 0 0.1em;
    white-space: nowrap;
    transition: background 0.2s;
}

.msg.bot .citation:hover {
    background: rgba(59, 130, 246, 0.3);
    text-decoration: none;
}

.msg.bot .references {
    margin-top: 1rem;
    padding-top: 0.75rem;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
    font-size: 0.8rem;
}

.msg.bot .ref-item {
    margin: 0.3rem 0;
    color: var(--text-secondary);
    opacity: 0.8;
    word-break: break-all;
}

.msg.bot .ref-item a {
    text-decoration: none;
    color: var(--accent);
}

.msg.bot .ref-item a:hover {
    text-decoration: underline;
}

.msg.bot .bullet {
    color: var(--accent);
    font-weight: bold;
    margin-right: 0.25rem;
}

.msg.bot em {
    color: var(--text-primary);
    font-style: italic;
}

/* Bio Modal */
.bio-modal {
    position: fixed;
    inset: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0);
    backdrop-filter: blur(0);
    opacity: 0;
    visibility: hidden;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.bio-modal.open {
    opacity: 1;
    visibility: visible;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(20px);
}

.bio-modal-content {
    width: 90%;
    max-width: 600px;
    max-height: 85vh;
    background: rgba(255, 255, 255, 0.98);
    border: 1px solid var(--card-border);
    border-radius: 20px;
    padding: 2.5rem;
    overflow-y: auto;
    transform: scale(0.9) translateY(30px);
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
}

.bio-modal.open .bio-modal-content {
    transform: scale(1) translateY(0);
}

.bio-modal-content h2 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    background: linear-gradient(to right, #1e293b, #3b82f6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.bio-modal-content p {
    font-size: 1rem;
    line-height: 1.7;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.bio-modal-content p:last-child {
    margin-bottom: 0;
}

.bio-modal-content strong {
    color: var(--accent);
}

.bio-modal-content em {
    color: var(--text-primary);
}

.bio-modal-close {
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
    width: 40px;
    height: 40px;
    border: none;
    background: rgba(0, 0, 0, 0.05);
    border-radius: 50%;
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.bio-modal-close:hover {
    background: rgba(0, 0, 0, 0.1);
    color: var(--text-primary);
    transform: rotate(90deg);
}