/* ============================================================
   DESIGN SYSTEM TOKENS
   ============================================================ */
:root {
    /* Color palette – Dark theme */
    --bg-deep: #06070a;
    --bg-surface: rgba(255, 255, 255, 0.035);
    --bg-surface-hover: rgba(255, 255, 255, 0.07);
    --bg-elevated: rgba(255, 255, 255, 0.05);
    --text-primary: #f0f0f5;
    --text-secondary: #9ca3af;
    --accent-cyan: #22d3ee;
    --accent-amber: #fbbf24;
    --accent-purple: #a78bfa;
    --accent-cyan-glow: rgba(34, 211, 238, 0.15);
    --accent-amber-glow: rgba(251, 191, 36, 0.12);
    --glass-border: rgba(255, 255, 255, 0.08);
    --glass-border-hover: rgba(255, 255, 255, 0.18);

    /* Typography */
    --font-body: 'Plus Jakarta Sans', 'Inter', system-ui, sans-serif;
    --font-display: 'Syne', 'Outfit', system-ui, sans-serif;

    /* Motion */
    --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
    --transition: all 0.45s var(--ease-out-expo);
    --transition-fast: all 0.25s var(--ease-out-expo);

    /* Radii */
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --radius-xl: 32px;
    --radius-full: 9999px;
}

/* Light theme overrides */
[data-theme="light"] {
    --bg-deep: #f8f9fc;
    --bg-surface: rgba(0, 0, 0, 0.03);
    --bg-surface-hover: rgba(0, 0, 0, 0.06);
    --bg-elevated: rgba(0, 0, 0, 0.04);
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --accent-cyan: #0891b2;
    --accent-amber: #d97706;
    --accent-purple: #7c3aed;
    --accent-cyan-glow: rgba(8, 145, 178, 0.08);
    --accent-amber-glow: rgba(217, 119, 6, 0.06);
    --glass-border: rgba(0, 0, 0, 0.08);
    --glass-border-hover: rgba(0, 0, 0, 0.16);
}

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

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    background-color: var(--bg-deep);
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.7;
    overflow-x: hidden;
    transition: background-color 0.6s ease, color 0.6s ease;
}

/* ============================================================
   ANIMATED BACKGROUND — Grid + floating orbs
   ============================================================ */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    z-index: -2;
    background-image:
        radial-gradient(circle at 15% 25%, var(--accent-cyan-glow) 0%, transparent 50%),
        radial-gradient(circle at 85% 75%, var(--accent-amber-glow) 0%, transparent 50%),
        radial-gradient(circle at 50% 50%, rgba(167, 139, 250, 0.04) 0%, transparent 60%);
    animation: bgShift 20s ease-in-out infinite alternate;
}

body::after {
    content: '';
    position: fixed;
    inset: 0;
    z-index: -1;
    background-image:
        linear-gradient(var(--glass-border) 1px, transparent 1px),
        linear-gradient(90deg, var(--glass-border) 1px, transparent 1px);
    background-size: 80px 80px;
    opacity: 0.25;
    mask-image: radial-gradient(ellipse 80% 60% at 50% 50%, black 20%, transparent 100%);
    -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 50%, black 20%, transparent 100%);
}

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

/* ============================================================
   TYPOGRAPHY
   ============================================================ */
h1, h2, h3, h4 {
    font-family: var(--font-display);
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.03em;
    line-height: 1.2;
}

h1 {
    font-size: clamp(2.8rem, 7vw, 5rem);
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-cyan) 50%, var(--accent-purple) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
}

h2 {
    font-size: clamp(1.8rem, 4vw, 2.4rem);
    margin-bottom: 2.5rem;
    display: flex;
    align-items: center;
    gap: 20px;
}

h2::after {
    content: '';
    height: 1px;
    flex-grow: 1;
    background: linear-gradient(to right, var(--accent-cyan), transparent 80%);
}

h3 { font-size: 1.5rem; }
h4 { font-size: 1.1rem; }

p, li {
    color: var(--text-secondary);
    line-height: 1.8;
}

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

/* ============================================================
   FLOATING NAV — Pill Island
   ============================================================ */
.nav-bar {
    position: fixed;
    top: 16px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1000;
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 24px;
    background: rgba(6, 7, 10, 0.65);
    backdrop-filter: blur(24px) saturate(1.8);
    -webkit-backdrop-filter: blur(24px) saturate(1.8);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-full);
    transition: var(--transition);
}

[data-theme="light"] .nav-bar {
    background: rgba(248, 249, 252, 0.7);
}

.nav-bar.scrolled {
    top: 10px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.25);
}

.nav-bar ul {
    list-style: none;
    display: flex;
    gap: 6px;
}

.nav-bar a {
    display: block;
    padding: 6px 14px;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-secondary);
    border-radius: var(--radius-full);
    transition: var(--transition-fast);
    position: relative;
    white-space: nowrap;
}

.nav-bar a:hover {
    color: var(--text-primary);
    background: var(--bg-surface-hover);
}

.nav-bar a.active {
    color: var(--bg-deep);
    background: var(--accent-cyan);
    font-weight: 600;
}

[data-theme="light"] .nav-bar a.active {
    color: #fff;
}

.theme-toggle {
    background: var(--bg-surface);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    width: 36px;
    height: 36px;
    border-radius: var(--radius-full);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    transition: var(--transition-fast);
    flex-shrink: 0;
    margin-left: 8px;
}

.theme-toggle:hover {
    background: var(--bg-surface-hover);
    transform: rotate(30deg) scale(1.1);
}

/* ============================================================
   LAYOUT
   ============================================================ */
.content-wrapper {
    max-width: 1300px;
    margin: 0 auto;
    padding: 110px 24px 80px;
}

.section {
    margin-bottom: 140px;
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.9s var(--ease-out-expo), transform 0.9s var(--ease-out-expo);
}

.section.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ============================================================
   HERO / BIO
   ============================================================ */
.hero-section {
    display: grid;
    grid-template-columns: 260px 1fr;
    gap: 50px;
    align-items: start;
    margin-bottom: 100px;
}

.profile-container {
    position: relative;
    display: flex;
    justify-content: center;
}

.profile-pic {
    width: 240px;
    height: 240px;
    border-radius: var(--radius-lg);
    object-fit: cover;
    z-index: 2;
    border: 2px solid var(--glass-border);
    transition: var(--transition);
    position: relative;
}

.profile-pic:hover {
    transform: scale(1.04) rotate(-1deg);
    border-color: var(--accent-cyan);
    box-shadow: 0 20px 60px rgba(34, 211, 238, 0.15);
}

.profile-container::before {
    content: '';
    position: absolute;
    top: -30px;
    left: -30px;
    right: -30px;
    bottom: -30px;
    background: radial-gradient(circle, var(--accent-cyan-glow) 0%, transparent 70%);
    z-index: 0;
    border-radius: 50%;
    animation: pulseGlow 4s ease-in-out infinite;
}

@keyframes pulseGlow {
    0%, 100% { opacity: 0.5; transform: scale(1); }
    50% { opacity: 1; transform: scale(1.05); }
}

.hero-subtitle {
    font-size: 1.15rem;
    color: var(--accent-cyan);
    font-weight: 500;
    margin-bottom: 1rem;
    letter-spacing: 0.02em;
}

.bio-content {
    display: flex;
    flex-direction: column;
}

.biography {
    background: var(--bg-surface);
    backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    padding: 36px;
    border-radius: var(--radius-lg);
    transition: var(--transition);
}

.biography:hover {
    border-color: var(--glass-border-hover);
}

.biography p {
    font-size: 1.05rem;
    color: var(--text-secondary);
    line-height: 1.85;
}

/* ============================================================
   SOCIAL ICONS
   ============================================================ */
.social-icons {
    display: flex;
    gap: 12px;
    margin-top: 28px;
}

.icon-link {
    width: 44px;
    height: 44px;
    background: var(--bg-surface);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.icon-link::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--accent-cyan-glow), var(--accent-amber-glow));
    opacity: 0;
    transition: var(--transition-fast);
}

.icon-link:hover {
    transform: translateY(-4px);
    border-color: var(--accent-cyan);
    box-shadow: 0 8px 24px rgba(34, 211, 238, 0.15);
}

.icon-link:hover::before {
    opacity: 1;
}

.icon-link img {
    width: 22px;
    height: 22px;
    position: relative;
    z-index: 1;
    filter: brightness(0.85);
    transition: var(--transition-fast);
}

.icon-link:hover img {
    filter: brightness(1.1);
    transform: scale(1.1);
}

/* ============================================================
   INTEREST / SKILL TAGS
   ============================================================ */
.section-label {
    font-family: var(--font-display);
    font-size: 0.82rem;
    font-weight: 700;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--accent-amber);
    margin: 20px 0 12px;
}

.section-sublabel {
    font-family: var(--font-body);
    font-size: 0.78rem;
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--text-secondary);
    margin: 10px 0 10px;
}

.interest-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.tag {
    background: var(--bg-surface);
    border: 1px solid var(--glass-border);
    padding: 6px 18px;
    border-radius: var(--radius-full);
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: var(--transition-fast);
    cursor: pointer;
    text-decoration: none;
}

.tag:hover {
    background: var(--accent-cyan);
    color: var(--bg-deep);
    border-color: var(--accent-cyan);
    transform: translateY(-2px);
    box-shadow: 0 4px 16px rgba(34, 211, 238, 0.25);
}

[data-theme="light"] .tag:hover {
    color: #fff;
}

/* ============================================================
   CARD GRID
   ============================================================ */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 580px), 1fr));
    gap: 32px;
}

/* ============================================================
   GLASS CARDS
   ============================================================ */
.glass-card {
    background: var(--bg-surface);
    border: 1px solid var(--glass-border);
    padding: 32px;
    border-radius: var(--radius-xl);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.glass-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 3px;
    height: 0;
    background: linear-gradient(180deg, var(--accent-cyan), var(--accent-purple));
    transition: height 0.5s var(--ease-out-expo);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.glass-card::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at var(--mouse-x, 50%) var(--mouse-y, 50%),
        rgba(34, 211, 238, 0.06) 0%, transparent 50%);
    opacity: 0;
    transition: opacity 0.4s ease;
    pointer-events: none;
}

.glass-card:hover {
    transform: translateY(-6px);
    border-color: var(--glass-border-hover);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2), 0 0 0 1px var(--glass-border-hover);
}

.glass-card:hover::before {
    height: 100%;
}

.glass-card:hover::after {
    opacity: 1;
}

.glass-card h3 {
    font-size: 1.4rem;
    margin-bottom: 0.6rem;
    color: var(--accent-cyan);
}

.glass-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 16px;
}

.glass-card ul {
    list-style: none;
    padding: 0;
}

.glass-card li {
    position: relative;
    padding-left: 22px;
    margin-bottom: 10px;
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.7;
}

.glass-card li::before {
    content: '›';
    position: absolute;
    left: 4px;
    color: var(--accent-cyan);
    font-weight: 700;
    font-size: 1.1rem;
}

/* ============================================================
   PROJECT MEDIA
   ============================================================ */
.project-media {
    width: 100%;
    height: 340px;
    border-radius: var(--radius-md);
    overflow: hidden;
    margin-bottom: 20px;
    background: var(--bg-elevated);
    border: 1px solid var(--glass-border);
    position: relative;
}

.project-media img,
.project-media video {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.7s var(--ease-out-expo);
}

.glass-card:hover .project-media img,
.glass-card:hover .project-media video,
.pub-card:hover .project-media img,
.pub-card:hover .project-media video {
    transform: scale(1.06);
}

/* ============================================================
   PROJECT & PUBLICATION TAGS
   ============================================================ */
.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 16px;
}

.p-tag {
    background: rgba(34, 211, 238, 0.08);
    border: 1px solid rgba(34, 211, 238, 0.18);
    padding: 3px 10px;
    border-radius: var(--radius-sm);
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--accent-cyan);
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.publication-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 16px;
}

.pub-tag {
    background: rgba(251, 191, 36, 0.08);
    border: 1px solid rgba(251, 191, 36, 0.2);
    padding: 3px 10px;
    border-radius: var(--radius-sm);
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--accent-amber);
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

/* ============================================================
   EXPERIENCE TIMELINE
   ============================================================ */
.experience-timeline {
    position: relative;
    padding-left: 32px;
}

.experience-timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(180deg, var(--accent-cyan), var(--accent-purple), var(--accent-amber));
    border-radius: var(--radius-full);
    opacity: 0.4;
}

.timeline-item {
    position: relative;
    margin-bottom: 32px;
    padding-left: 32px;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -37px;
    top: 18px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--bg-deep);
    border: 2px solid var(--accent-cyan);
    z-index: 2;
    transition: var(--transition-fast);
}

.timeline-item:hover::before {
    background: var(--accent-cyan);
    box-shadow: 0 0 12px var(--accent-cyan-glow);
    transform: scale(1.3);
}

.job-card {
    background: var(--bg-surface);
    border: 1px solid var(--glass-border);
    padding: 28px;
    border-radius: var(--radius-lg);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.job-card:hover {
    border-color: var(--glass-border-hover);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15);
}

.job-header {
    cursor: pointer;
    display: flex;
    align-items: flex-start;
    gap: 16px;
}

.job-header > div:first-child {
    flex: 1;
    min-width: 0;
}

.job-header-right {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-shrink: 0;
    padding-top: 2px;
}

.job-toggle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    transition: var(--transition-fast);
    width: 24px;
    text-align: center;
    flex-shrink: 0;
    user-select: none;
}

.job-header.expanded .job-toggle {
    color: var(--accent-cyan);
}

.job-title-text {
    font-family: var(--font-display);
    font-weight: 700;
    font-size: 1.15rem;
    color: var(--accent-cyan);
    line-height: 1.4;
}

.company-name {
    color: var(--text-secondary);
    font-size: 0.88rem;
    font-style: italic;
    margin-top: 2px;
}

.job-date {
    color: var(--text-secondary);
    font-size: 0.82rem;
    white-space: nowrap;
    background: var(--bg-elevated);
    padding: 4px 14px;
    border-radius: var(--radius-full);
    font-weight: 500;
    border: 1px solid var(--glass-border);
}

.job-details {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.5s var(--ease-out-expo), padding 0.3s ease;
    padding-top: 0;
}

.job-details.active {
    max-height: 600px;
    padding-top: 20px;
}

.job-details ul {
    list-style: none;
}

.job-details li {
    position: relative;
    padding-left: 22px;
    margin-bottom: 10px;
    color: var(--text-secondary);
    font-size: 0.92rem;
    line-height: 1.7;
}

.job-details li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--accent-cyan);
    font-weight: 700;
}

/* ============================================================
   EDUCATION CARDS
   ============================================================ */
.edu-card {
    background: var(--bg-surface);
    border: 1px solid var(--glass-border);
    padding: 32px;
    border-radius: var(--radius-xl);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.edu-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-cyan), var(--accent-purple));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.5s var(--ease-out-expo);
}

.edu-card:hover {
    transform: translateY(-4px);
    border-color: var(--glass-border-hover);
    box-shadow: 0 16px 48px rgba(0, 0, 0, 0.15);
}

.edu-card:hover::before {
    transform: scaleX(1);
}

.edu-card h3 {
    color: var(--accent-cyan);
    font-size: 1.3rem;
    margin-bottom: 4px;
}

.edu-card .company-name {
    font-size: 0.92rem;
}

/* ============================================================
   ROBOTS & SENSORS TAXONOMY GRID
   ============================================================ */
.tax-section-title {
    font-family: var(--font-display);
    font-size: 0.9rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--accent-amber);
    margin: 24px 0 14px;
}

.tax-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 12px;
}

.tax-item {
    background: var(--bg-surface);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    padding: 16px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.tax-item::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, var(--accent-cyan), transparent);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.4s var(--ease-out-expo);
}

.tax-item:hover {
    background: var(--bg-surface-hover);
    transform: translateY(-3px);
    border-color: var(--glass-border-hover);
}

.tax-item:hover::after {
    transform: scaleX(1);
}

.tax-title {
    font-family: var(--font-display);
    font-weight: 700;
    font-size: 0.95rem;
    color: var(--text-primary);
    margin-bottom: 8px;
}

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

/* ============================================================
   PUBLICATION CARDS
   ============================================================ */
.pub-card {
    background: var(--bg-surface);
    border: 1px solid var(--glass-border);
    padding: 28px;
    border-radius: var(--radius-lg);
    display: flex;
    flex-direction: column;
    gap: 14px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.pub-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-amber), var(--accent-purple));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.5s var(--ease-out-expo);
}

.pub-card:hover {
    border-color: var(--accent-amber);
    box-shadow: 0 16px 48px rgba(251, 191, 36, 0.08);
    transform: translateY(-4px);
}

.pub-card:hover::before {
    transform: scaleX(1);
}

.pub-title {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.4;
}

.pub-venue {
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--accent-amber);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    background: var(--accent-amber-glow);
    padding: 3px 10px;
    border-radius: var(--radius-full);
    width: fit-content;
}

.pub-authors {
    font-size: 0.9rem;
    font-style: italic;
    color: var(--text-secondary);
    line-height: 1.6;
}

.author-highlight {
    color: var(--accent-amber);
    font-weight: 700;
    font-style: italic;
}

.pub-description {
    color: var(--text-secondary);
    font-size: 0.92rem;
    line-height: 1.7;
}

.pub-card li {
    color: var(--text-secondary);
    font-size: 0.92rem;
    line-height: 1.7;
    margin-bottom: 6px;
    padding-left: 18px;
    position: relative;
    list-style: none;
}

.pub-card li::before {
    content: '›';
    position: absolute;
    left: 2px;
    color: var(--accent-amber);
    font-weight: 700;
}

/* ============================================================
   BUTTONS
   ============================================================ */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 22px;
    background: var(--bg-surface);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    border-radius: var(--radius-md);
    cursor: pointer;
    font-weight: 600;
    font-size: 0.88rem;
    transition: var(--transition);
    text-decoration: none;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--accent-cyan), var(--accent-purple));
    opacity: 0;
    transition: opacity 0.3s ease;
}

.btn span {
    position: relative;
    z-index: 1;
}

.btn:hover {
    border-color: var(--accent-cyan);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(34, 211, 238, 0.15);
    color: var(--text-primary);
}

.btn:hover::before {
    opacity: 0.15;
}

/* ============================================================
   BACK TO TOP
   ============================================================ */
.back-to-top {
    position: fixed;
    bottom: 28px;
    right: 28px;
    width: 48px;
    height: 48px;
    background: var(--accent-cyan);
    color: var(--bg-deep);
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    font-weight: 700;
    opacity: 0;
    pointer-events: none;
    transform: translateY(10px);
    transition: var(--transition);
    z-index: 100;
    box-shadow: 0 8px 24px rgba(34, 211, 238, 0.25);
}

.back-to-top.show {
    opacity: 1;
    pointer-events: all;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 32px rgba(34, 211, 238, 0.35);
}

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
    text-align: center;
    padding: 40px 24px;
    color: var(--text-secondary);
    font-size: 0.82rem;
    border-top: 1px solid var(--glass-border);
    margin-top: -60px;
}

.site-footer a {
    color: var(--accent-cyan);
    transition: var(--transition-fast);
}

.site-footer a:hover {
    color: var(--accent-amber);
}

/* ============================================================
   STAGGERED ENTRANCE ANIMATIONS
   ============================================================ */
.stagger-item {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.6s var(--ease-out-expo), transform 0.6s var(--ease-out-expo);
}

.section.visible .stagger-item {
    opacity: 1;
    transform: translateY(0);
}

.section.visible .stagger-item:nth-child(1) { transition-delay: 0.05s; }
.section.visible .stagger-item:nth-child(2) { transition-delay: 0.12s; }
.section.visible .stagger-item:nth-child(3) { transition-delay: 0.19s; }
.section.visible .stagger-item:nth-child(4) { transition-delay: 0.26s; }
.section.visible .stagger-item:nth-child(5) { transition-delay: 0.33s; }
.section.visible .stagger-item:nth-child(6) { transition-delay: 0.40s; }
.section.visible .stagger-item:nth-child(7) { transition-delay: 0.47s; }
.section.visible .stagger-item:nth-child(8) { transition-delay: 0.54s; }
.section.visible .stagger-item:nth-child(9) { transition-delay: 0.61s; }

/* ============================================================
   RESPONSIVE – TABLET
   ============================================================ */
@media (max-width: 1024px) {
    .hero-section {
        grid-template-columns: 200px 1fr;
        gap: 32px;
    }

    .profile-pic {
        width: 200px;
        height: 200px;
    }

    .content-wrapper {
        padding: 100px 20px 60px;
    }

    .section {
        margin-bottom: 100px;
    }
}

/* ============================================================
   RESPONSIVE – MOBILE
   ============================================================ */
@media (max-width: 768px) {
    .hero-section {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 28px;
        margin-bottom: 60px;
    }

    .profile-pic {
        width: 180px;
        height: 180px;
    }

    .social-icons {
        justify-content: center;
    }

    .nav-bar {
        top: auto;
        bottom: 16px;
        transform: translateX(-50%);
        padding: 8px 16px;
        border-radius: var(--radius-lg);
        max-width: calc(100vw - 32px);
        overflow-x: auto;
    }

    .nav-bar.scrolled {
        top: auto;
        bottom: 10px;
    }

    .nav-bar ul {
        gap: 4px;
    }

    .nav-bar a {
        font-size: 0.75rem;
        padding: 5px 10px;
    }

    .content-wrapper {
        padding: 40px 16px 100px;
    }

    h1 {
        font-size: clamp(2rem, 8vw, 2.8rem);
    }

    h2 {
        font-size: 1.6rem;
    }

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

    .section {
        margin-bottom: 80px;
    }

    .biography {
        padding: 24px;
    }

    .glass-card {
        padding: 24px;
    }

    .project-media {
        height: 220px;
    }

    .interest-tags {
        justify-content: center;
    }

    .tax-grid {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    }
}

/* ============================================================
   SCROLLBAR
   ============================================================ */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: var(--bg-deep);
}

::-webkit-scrollbar-thumb {
    background: var(--glass-border);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-cyan);
}

/* ============================================================
   SELECTION
   ============================================================ */
::selection {
    background: rgba(34, 211, 238, 0.25);
    color: var(--text-primary);
}