:root {
    /* Light Mode (Default) */
    --bg-color: #f8f9fa;
    --text-primary: #1a1a1a;
    --text-secondary: #6b7280;
    --accent-primary: #8b5cf6;
    --accent-secondary: #3b82f6;
    --accent-tertiary: #ec4899;
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(0, 0, 0, 0.1);
    --glass-blur: blur(16px);
    --card-bg: #ffffff;
    --nav-bg: rgba(255, 255, 255, 0.8);
    --grid-line: rgba(0, 0, 0, 0.05);
    --blob-opacity: 0.08;
    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
    --font-serif: 'Bricolage Grotesque', serif;
    --transition-smooth: all 0.6s cubic-bezier(0.16, 1, 0.3, 1);
    --transition-snappy: all 0.3s ease-out;
}

/* Dark Mode */
[data-theme="dark"] {
    --bg-color: #050505;
    --text-primary: #ffffff;
    --text-secondary: #a1a1aa;
    --glass-bg: rgba(255, 255, 255, 0.03);
    --glass-border: rgba(255, 255, 255, 0.08);
    --card-bg: #0a0a0a;
    --nav-bg: rgba(10, 10, 10, 0.4);
    --grid-line: rgba(255, 255, 255, 0.03);
    --blob-opacity: 0.12;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-sans);
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
}

/* Grid Overlay Texture */
.grid-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: linear-gradient(var(--grid-line) 1px, transparent 1px),
        linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
    background-size: 40px 40px;
    z-index: -1;
    pointer-events: none;
}

/* Moving Gradient Background */
.gradient-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -2;
    overflow: hidden;
    background: radial-gradient(circle at 50% 50%, #f0f0f0, #e5e5e5);
    transition: background 0.6s ease;
}

[data-theme="dark"] .gradient-bg {
    background: radial-gradient(circle at 50% 50%, #050505, #000);
}

.gradient-blob {
    position: absolute;
    width: 800px;
    height: 800px;
    border-radius: 50%;
    filter: blur(100px);
    opacity: var(--blob-opacity);
    animation: move 25s infinite alternate;
    pointer-events: none;
}

.blob-1 {
    background: var(--accent-primary);
    top: -20%;
    left: -10%;
    animation-duration: 30s;
}

.blob-2 {
    background: var(--accent-secondary);
    bottom: -20%;
    right: -10%;
    animation-duration: 35s;
    animation-delay: -5s;
}

.blob-3 {
    background: var(--accent-tertiary);
    top: 30%;
    left: 30%;
    animation-duration: 40s;
    animation-delay: -10s;
}

@keyframes move {
    0% {
        transform: translate(0, 0) scale(1) rotate(0deg);
    }

    33% {
        transform: translate(15%, 20%) scale(1.2) rotate(10deg);
    }

    66% {
        transform: translate(-15%, 10%) scale(0.8) rotate(-10deg);
    }

    100% {
        transform: translate(0, 0) scale(1) rotate(0deg);
    }
}

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

section {
    padding: 12rem 0;
}

/* Pill Navigation */
.pill-nav {
    position: fixed;
    top: 2rem;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1000;
    width: auto;
}

.nav-container {
    background: var(--nav-bg);
    border: 1px solid var(--glass-border);
    backdrop-filter: var(--glass-blur);
    border-radius: 100px;
    padding: 0.6rem 2rem;
    display: flex;
    align-items: center;
    gap: 3rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

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

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition-snappy);
    letter-spacing: 0.02em;
}

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

.nav-logo {
    font-family: var(--font-serif);
    font-weight: 800;
    font-size: 1.2rem;
    background: linear-gradient(to right, #1a1a1a, var(--text-secondary));
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

[data-theme="dark"] .nav-logo {
    background: linear-gradient(to right, #fff, var(--text-secondary));
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Typography */
h1 {
    font-family: var(--font-serif);
    font-size: clamp(4rem, 12vw, 8.5rem);
    font-weight: 800;
    line-height: 0.9;
    letter-spacing: -0.05em;
    margin-bottom: 2.5rem;
    background: linear-gradient(to bottom, #1a1a1a 50%, rgba(26, 26, 26, 0.6));
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

[data-theme="dark"] h1 {
    background: linear-gradient(to bottom, #fff 50%, rgba(255, 255, 255, 0.6));
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

h2,
h3 {
    font-family: var(--font-serif);
}

.section-title {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 800;
    letter-spacing: -0.04em;
    margin-bottom: 6rem;
    text-align: center;
}

.hero-subtitle {
    font-size: clamp(1.2rem, 2.2vw, 1.6rem);
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto 4rem;
    font-weight: 400;
}

/* Hero Section */
header#hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    position: relative;
    padding-top: 6rem;
}

/* Technology Playground Updates */
.technology-playground {
    position: relative;
    width: 100%;
}

.gravity-btn {
    position: absolute;
    top: 20px;
    right: 20px;
    z-index: 10;
    padding: 10px 18px;
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 30px;
    color: var(--text-primary);
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 0.5px;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.gravity-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--accent-primary);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(139, 92, 246, 0.3);
}

.gravity-btn.active {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: white;
}

.physics-playground {
    width: 60vw;
    margin: 0 auto;
    height: 600px;
    position: relative;
    overflow: hidden;
    cursor: grab;
}

.physics-playground:active {
    cursor: grabbing;
}

.physics-playground canvas {
    display: block;
    touch-action: pan-y;
    /* Allow vertical scrolling/swiping through the canvas */
}

.physics-instruction {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.3em;
    pointer-events: none;
    opacity: 0.3;
    z-index: 0;
    text-align: center;
    width: 100%;
}

/* Grid Components */
.grid {
    display: grid;
    gap: 2rem;
}

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

/* Stacking Project Grid */
.project-grid {
    display: flex;
    flex-direction: column;
    gap: 4rem;
    perspective: 1000px;
}

/* Cards */
.card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 32px;
    padding: 2.5rem;
    transition: var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.card:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.15);
    transform: translateY(-8px);
}

/* Project Stacking Logic */
.project-card {
    position: sticky;
    top: 8rem;
    min-height: 500px;
    background: var(--card-bg);
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    padding: 0;
    align-items: stretch;
    box-shadow: 0 -20px 40px rgba(0, 0, 0, 0.4);
}

@media (max-width: 900px) {
    .project-card {
        grid-template-columns: 1fr;
        min-height: auto;
    }
}

/* Tech Cards */
.tech-card .tech-icon {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    display: block;
}

.tech-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
}

.tech-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* Project Cards */
.project-card {
    padding: 0;
    display: flex;
    flex-direction: column;
}

.project-image {
    width: 100%;
    aspect-ratio: 16/10;
    background: #111;
    overflow: hidden;
    border-bottom: 1px solid var(--glass-border);
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition-smooth);
}

.project-card:hover .project-image img {
    transform: scale(1.05);
}

.project-card:hover {
    background: var(--card-bg) !important;
    /* Ensure opacity to prevent text bleeding from underlying sticky cards */
    border-color: var(--glass-border);
}

.project-info {
    padding: 1.5rem;
}

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

.tag {
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 0.25rem 0.75rem;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 100px;
    color: var(--text-secondary);
}

/* Buttons */
.btn {
    padding: 0.8rem 2rem;
    border-radius: 100px;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition-smooth);
    display: inline-block;
    font-size: 0.9rem;
}

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

.btn-primary:hover {
    transform: scale(1.05);
    box-shadow: 0 0 40px rgba(255, 255, 255, 0.2);
}

/* Master Footer */
.master-footer {
    padding: 8rem 0 0 0;
    position: relative;
    overflow: hidden;
}

.footer-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4rem;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0;
}

.footer-cta {
    text-align: center;
    width: 100%;
    padding: 4rem 2rem;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    position: relative;
    transition: background 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    overflow: hidden;
}

.lets-connect-btn:hover~.footer-cta,
.footer-cta:has(.lets-connect-btn:hover) {
    background: linear-gradient(135deg, #ff6b6b 0%, #ee5a6f 50%, #ff6348 100%);
}

/* Animated particles */
.particles {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    overflow: hidden;
}

/* curved arc SVG that separates the gradient CTA from the dark footer */
.footer-cta:has(.lets-connect-btn:hover) .particle {
    background: rgba(0, 0, 0, 0.3);
}

.lets-connect-btn {
    font-family: 'Bricolage Grotesque', sans-serif;
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 400;
    color: var(--text-primary);
    text-decoration: none;
    padding: 1.5rem 4rem;
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 999px;
    display: inline-block;
    transition: all 0.4s cubic-bezier(0.2, 0, 0.2, 1);
    background: transparent;
}

.lets-connect-btn:hover {
    transform: scale(1.05);
    background: rgba(255, 255, 255, 0.95);
    color: #000;
    border-color: rgba(255, 255, 255, 0.95);
}

.particle {
    position: absolute;
    width: 3px;
    height: 3px;
    background: rgba(255, 255, 255, 0.4);
    border-radius: 50%;
    animation: float 15s infinite ease-in-out;
    transition: background 0.4s ease;
}

.footer-cta:has(.lets-connect-btn:hover) .particle {
    background: rgba(0, 0, 0, 0.3);
}

.particle:nth-child(1) {
    left: 10%;
    top: 20%;
    animation-delay: 0s;
    animation-duration: 12s;
}

.particle:nth-child(2) {
    left: 25%;
    top: 60%;
    animation-delay: 2s;
    animation-duration: 15s;
}

.particle:nth-child(3) {
    left: 40%;
    top: 30%;
    animation-delay: 4s;
    animation-duration: 18s;
}

.particle:nth-child(4) {
    left: 60%;
    top: 70%;
    animation-delay: 1s;
    animation-duration: 14s;
}

.particle:nth-child(5) {
    left: 75%;
    top: 40%;
    animation-delay: 3s;
    animation-duration: 16s;
}

.particle:nth-child(6) {
    left: 85%;
    top: 25%;
    animation-delay: 5s;
    animation-duration: 13s;
}

.particle:nth-child(7) {
    left: 50%;
    top: 80%;
    animation-delay: 2.5s;
    animation-duration: 17s;
}

.particle:nth-child(8) {
    left: 20%;
    top: 50%;
    animation-delay: 4.5s;
    animation-duration: 15s;
}

.particle:nth-child(9) {
    left: 15%;
    top: 35%;
    animation-delay: 1.5s;
    animation-duration: 14s;
}

.particle:nth-child(10) {
    left: 35%;
    top: 65%;
    animation-delay: 3.5s;
    animation-duration: 16s;
}

.particle:nth-child(11) {
    left: 55%;
    top: 15%;
    animation-delay: 0.5s;
    animation-duration: 13s;
}

.particle:nth-child(12) {
    left: 70%;
    top: 55%;
    animation-delay: 2.8s;
    animation-duration: 17s;
}

.particle:nth-child(13) {
    left: 90%;
    top: 45%;
    animation-delay: 4.2s;
    animation-duration: 15s;
}

.particle:nth-child(14) {
    left: 5%;
    top: 75%;
    animation-delay: 1.8s;
    animation-duration: 14s;
}

.particle:nth-child(15) {
    left: 45%;
    top: 10%;
    animation-delay: 3.2s;
    animation-duration: 16s;
}

.particle:nth-child(16) {
    left: 65%;
    top: 85%;
    animation-delay: 0.8s;
    animation-duration: 18s;
}

.particle:nth-child(17) {
    left: 80%;
    top: 60%;
    animation-delay: 4.8s;
    animation-duration: 13s;
}

.particle:nth-child(18) {
    left: 30%;
    top: 45%;
    animation-delay: 2.2s;
    animation-duration: 15s;
}

.particle:nth-child(19) {
    left: 95%;
    top: 20%;
    animation-delay: 3.8s;
    animation-duration: 17s;
}

.particle:nth-child(20) {
    left: 12%;
    top: 90%;
    animation-delay: 1.2s;
    animation-duration: 14s;
}

@keyframes float {

    0%,
    100% {
        transform: translateY(0) translateX(0);
        opacity: 0.4;
    }

    50% {
        transform: translateY(-30px) translateX(20px);
        opacity: 0.8;
    }
}

/* Curved arc at bottom */
.footer-arc {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 150px;
    color: rgba(0, 0, 0, 0.1);
    pointer-events: none;
}

.footer-cta:has(.lets-connect-btn:hover) .footer-arc {
    color: rgba(0, 0, 0, 0.15);
}

.cta-label {
    text-transform: uppercase;
    letter-spacing: 0.15em;
    font-size: 0.8rem;
    color: rgba(255, 255, 255, 0.6);
    display: block;
    margin-bottom: 2rem;
    transition: color 0.4s ease;
}

.footer-cta:has(.lets-connect-btn:hover) .cta-label {
    color: rgba(255, 255, 255, 0.9);
}

.lets-connect-btn {
    font-family: 'Bricolage Grotesque', sans-serif;
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 400;
    color: var(--text-primary);
    text-decoration: none;
    padding: 1.5rem 4rem;
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 999px;
    display: inline-block;
    transition: all 0.4s cubic-bezier(0.2, 0, 0.2, 1);
    background: transparent;
}

.lets-connect-btn:hover {
    transform: scale(1.05);
    background: rgba(255, 255, 255, 0.95);
    color: #000;
    border-color: rgba(255, 255, 255, 0.95);
}

.cta-subtext {
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.85rem;
    margin: 2rem auto 3rem auto;
    max-width: 500px;
    transition: color 0.4s ease;
}

.footer-cta:has(.lets-connect-btn:hover) .cta-subtext {
    color: rgba(255, 255, 255, 0.85);
}

.contact-email {
    font-size: clamp(2rem, 6vw, 4rem);
    font-weight: 800;
    color: var(--text-primary);
    text-decoration: none;
    letter-spacing: -0.02em;
    display: block;
    margin: 0 0 1rem 0;
    transition: var(--transition-smooth);
}

.contact-email:hover {
    opacity: 0.7;
}

.location-text {
    color: var(--text-secondary);
    font-size: 1rem;
    margin: 0.5rem 0 2rem 0;
}

.footer-contact-info {
    text-align: center;
    margin-top: 4rem;
}

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

.social-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.social-link:hover {
    color: var(--text-primary);
    transform: scale(1.1);
}

.footer-bottom {
    width: 100%;
    text-align: center;
    padding: 3rem 0;
    border-top: 1px solid var(--glass-border);
}

.footer-credits {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin: 0;
}

.massive-footer-text {
    font-size: clamp(5rem, 20vw, 15rem);
    font-weight: 900;
    line-height: 0.8;
    text-align: center;
    width: 100%;
    margin-top: 2rem;
    background: linear-gradient(to bottom, #1a1a1a, #666);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    opacity: 0.15;
    letter-spacing: -0.05em;
    pointer-events: none;
    user-select: none;
}

[data-theme="dark"] .massive-footer-text {
    background: linear-gradient(to bottom, #fff, #333);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Competencies Section */
#competencies {
    background: linear-gradient(to bottom, transparent, rgba(139, 92, 246, 0.03));
}

.section-subtitle {
    font-size: clamp(1rem, 2vw, 1.3rem);
    color: var(--text-secondary);
    text-align: center;
    margin: -4rem auto 4rem;
    font-weight: 500;
    letter-spacing: 0.02em;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.competencies-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(360px, 1fr));
    gap: 2rem;
    margin-top: 4rem;
}

@media (max-width: 768px) {
    .competencies-grid {
        grid-template-columns: 1fr;
    }
}

.competency-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    padding: 2.5rem;
    transition: var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.competency-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-primary), var(--accent-secondary), var(--accent-tertiary));
    opacity: 0;
    transition: opacity 0.4s ease;
}

.competency-card:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.15);
    transform: translateY(-8px);
}

.competency-card:hover::before {
    opacity: 1;
}

.competency-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--glass-border);
}

.competency-icon {
    font-size: 2.5rem;
    line-height: 1;
    filter: grayscale(0.3);
    transition: all 0.3s ease;
}

.competency-card:hover .competency-icon {
    filter: grayscale(0);
    transform: scale(1.1);
}

.competency-header h3 {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text-primary);
    margin: 0;
    letter-spacing: -0.02em;
}

.competency-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.competency-list li {
    padding: 0.6rem 0;
    padding-left: 1.5rem;
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
    position: relative;
    transition: all 0.3s ease;
}

.competency-list li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--accent-primary);
    font-size: 1.2rem;
    line-height: 1.6;
    transition: all 0.3s ease;
}

.competency-list li:hover {
    color: var(--text-primary);
    padding-left: 2rem;
}

.competency-list li:hover::before {
    color: var(--accent-secondary);
    transform: translateX(5px);
}

/* Reveal Animations */
[data-reveal] {
    opacity: 0;
    transform: translateY(20px) scale(0.98);
    transition: all 0.8s cubic-bezier(0.2, 0, 0.2, 1);
}

[data-reveal].active {
    opacity: 1;
    transform: translateY(0) scale(1);
}

/* Tech Arsenal Section */
#tech-arsenal {
    padding: 100px 5%;
    background: radial-gradient(circle at center, rgba(99, 102, 241, 0.05) 0%, transparent 70%);
    position: relative;
    overflow: hidden;
}

#physics-playground {
    width: 100%;
    max-width: 1200px;
    margin: 40px auto;
    border-radius: 24px;
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    position: relative;
    cursor: grab;
    overflow: hidden;
}

/* Theme Toggle Button */
.theme-toggle {
    position: fixed;
    top: 2rem;
    right: 2rem;
    z-index: 1001;
    /* Above nav if necessary */
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    backdrop-filter: var(--glass-blur);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    transition: var(--transition-smooth);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.theme-toggle:hover {
    transform: scale(1.1) rotate(15deg);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.2);
    background: var(--card-bg);
    border-color: var(--accent-primary);
}

.theme-toggle:active {
    transform: scale(0.95);
}

.theme-icon {
    transition: all 0.3s ease;
}

/* Responsive Handling */
.mobile-only {
    display: none;
}

@media (max-width: 768px) {
    #physics-playground {
        display: none !important;
    }

    .mobile-only {
        display: block !important;
    }

    .tech-grid {
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
        gap: 1.5rem;
        padding: 1rem 0;
    }

    .tech-item {
        background: var(--glass-bg);
        border: 1px solid var(--glass-border);
        border-radius: 20px;
        padding: 1.5rem;
        display: flex;
        flex-direction: column;
        align-items: center;
        gap: 0.75rem;
        transition: var(--transition-snappy);
    }

    .tech-item i {
        font-size: 2.5rem;
        color: var(--accent-primary);
    }

    .tech-item span {
        font-size: 0.9rem;
        font-weight: 600;
        color: var(--text-primary);
    }

    nav {
        bottom: 1.5rem;
        top: auto;
    }

    .nav-links {
        gap: 1rem;
    }

    h1 {
        font-size: 3.5rem;
    }

    section {
        padding: 6rem 0;
    }

    .theme-toggle {
        top: 1.5rem;
        right: 1.5rem;
        bottom: auto;
    }
}

/* Chatbot Widget Styles */
.chatbot-widget {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    z-index: 10000;
    font-family: var(--font-sans);
}

.chat-toggle {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: var(--accent-primary);
    border: none;
    cursor: pointer;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-snappy);
    color: white;
}

.chat-toggle:hover {
    transform: scale(1.1) rotate(5deg);
    background: var(--accent-secondary);
}

.chat-icon,
.close-icon {
    font-size: 1.5rem;
}

.chat-window {
    position: absolute;
    bottom: 80px;
    right: 0;
    width: 380px;
    height: 550px;
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.3);
    transform: scale(0.9) translateY(20px);
    opacity: 0;
    pointer-events: none;
    transition: var(--transition-smooth);
    transform-origin: bottom right;
}

.chat-window.active {
    transform: scale(1) translateY(0);
    opacity: 1;
    pointer-events: all;
}

.chat-header {
    padding: 1.5rem;
    background: var(--accent-primary);
    color: white;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.chat-header-info {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.bot-avatar {
    font-size: 1.5rem;
    background: rgba(255, 255, 255, 0.2);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.chat-header h4 {
    margin: 0;
    font-size: 1rem;
    font-weight: 600;
}

.status-indicator {
    font-size: 0.75rem;
    opacity: 0.8;
}

.close-chat-btn {
    background: none;
    border: none;
    color: white;
    font-size: 1.2rem;
    cursor: pointer;
    opacity: 0.7;
    transition: opacity 0.3s;
}

.close-chat-btn:hover {
    opacity: 1;
}

.chat-messages {
    flex: 1;
    padding: 1.5rem;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    scrollbar-width: thin;
    scrollbar-color: var(--accent-primary) transparent;
}

.message {
    max-width: 80%;
    padding: 0.75rem 1rem;
    border-radius: 16px;
    font-size: 0.95rem;
    line-height: 1.4;
    animation: fadeIn 0.3s ease-out forwards;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(5px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.user-message {
    align-self: flex-end;
    background: var(--accent-primary);
    color: white;
    border-bottom-right-radius: 4px;
}

.bot-message {
    align-self: flex-start;
    background: var(--card-bg);
    color: var(--text-primary);
    border: 1px solid var(--glass-border);
    border-bottom-left-radius: 4px;
}

.chat-input-container {
    padding: 1rem 1.5rem;
    background: rgba(255, 255, 255, 0.05);
    border-top: 1px solid var(--glass-border);
    display: flex;
    gap: 0.75rem;
}

.chat-input-container input {
    flex: 1;
    background: transparent;
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    padding: 0.75rem 1rem;
    color: var(--text-primary);
    font-family: var(--font-sans);
    outline: none;
    transition: border-color 0.3s;
}

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

.send-btn {
    background: var(--accent-primary);
    color: white;
    border: none;
    width: 45px;
    height: 45px;
    border-radius: 12px;
    cursor: pointer;
    transition: var(--transition-snappy);
    display: flex;
    align-items: center;
    justify-content: center;
}

.send-btn:hover {
    transform: scale(1.05);
    background: var(--accent-secondary);
}

/* Typing Indicator */
.typing {
    display: flex;
    gap: 4px;
    padding: 10px;
}

.typing span {
    width: 6px;
    height: 6px;
    background: var(--text-secondary);
    border-radius: 50%;
    animation: bounce 1.4s infinite ease-in-out both;
}

.typing span:nth-child(1) {
    animation-delay: -0.32s;
}

.typing span:nth-child(2) {
    animation-delay: -0.16s;
}

@keyframes bounce {

    0%,
    80%,
    100% {
        transform: scale(0);
    }

    40% {
        transform: scale(1.0);
    }
}

/* Mobile adjustments for chat */
@media (max-width: 480px) {
    .chat-window {
        width: calc(100vw - 4rem);
        height: 70vh;
    }
}

/* Language Switcher */
.lang-switcher {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding-left: 2rem;
    border-left: 1px solid var(--glass-border);
}

.lang-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    transition: var(--transition-snappy);
    opacity: 0.7;
}

.lang-btn:hover {
    color: var(--text-primary);
    opacity: 1;
}

.lang-btn.active {
    color: var(--accent-primary);
    opacity: 1;
    background: rgba(139, 92, 246, 0.1);
}

.lang-divider {
    color: var(--text-secondary);
    font-size: 0.8rem;
    opacity: 0.5;
}

/* Mobile adjustments for nav */
@media (max-width: 900px) {
    .nav-container {
        flex-direction: column;
        gap: 1.5rem;
        padding: 1.5rem 2rem;
        border-radius: 20px;
    }

    .lang-switcher {
        padding-left: 0;
        border-left: none;
        border-top: 1px solid var(--glass-border);
        padding-top: 1rem;
        width: 100%;
        justify-content: center;
    }
}