/* ═══════════════════════════════════════════
   Design System — MD Abdul Momin Portfolio
   ═══════════════════════════════════════════ */

:root {
    /* Color Palette - Dark Navy Theme */
    --navy:       #0a192f;
    --navy-light: #112240;
    --navy-lighter:#1d3461;
    --slate:      #8892b0;
    --slate-light:#a8b2d1;
    --lightest:   #ccd6f6;
    --white:      #e6f1ff;
    --accent:     #64ffda;
    --accent-dim: rgba(100, 255, 218, 0.1);
    --accent-glow:rgba(100, 255, 218, 0.25);
    --gold:       #ffd700;
    --danger:     #ff6b6b;
    --purple:     #a78bfa;
    --blue:       #60a5fa;

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

    /* Spacing */
    --section-padding: 100px 0;
    --container-max: 1100px;

    /* Transitions */
    --transition: all 0.25s cubic-bezier(0.645, 0.045, 0.355, 1);
    --transition-slow: all 0.5s cubic-bezier(0.645, 0.045, 0.355, 1);
}

/* ═══════════════════════════════════════════
   Base Reset & Typography
   ═══════════════════════════════════════════ */

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

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

body {
    font-family: var(--font-sans);
    background-color: var(--navy);
    color: var(--slate);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

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

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

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

img {
    max-width: 100%;
    display: block;
}

.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 25px;
}

/* ═══════════════════════════════════════════
   Navigation
   ═══════════════════════════════════════════ */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 15px 50px;
    transition: var(--transition);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.navbar.scrolled {
    background-color: rgba(10, 25, 47, 0.92);
    box-shadow: 0 10px 30px -10px rgba(2, 12, 27, 0.7);
    padding: 10px 50px;
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1400px;
    margin: 0 auto;
}

.nav-logo {
    font-family: var(--font-mono);
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--accent);
    letter-spacing: -1px;
}

.logo-bracket {
    color: var(--accent);
    font-weight: 400;
}

.nav-links {
    display: flex;
    align-items: center;
    list-style: none;
    gap: 5px;
}

.nav-link {
    font-family: var(--font-mono);
    font-size: 0.82rem;
    color: var(--lightest);
    padding: 8px 14px;
    border-radius: 4px;
    transition: var(--transition);
    position: relative;
}

.nav-link:hover {
    color: var(--accent);
    background-color: var(--accent-dim);
}

.btn-resume {
    border: 1px solid var(--accent);
    color: var(--accent) !important;
    border-radius: 4px;
    padding: 8px 16px !important;
    margin-left: 10px;
}

.btn-resume:hover {
    background-color: var(--accent-dim);
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 10px;
}

.hamburger {
    width: 30px;
    height: 2px;
    background: var(--accent);
    position: relative;
    transition: var(--transition);
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--accent);
    transition: var(--transition);
}

.hamburger::before { top: -8px; }
.hamburger::after { bottom: -8px; }

/* ═══════════════════════════════════════════
   Hero Section
   ═══════════════════════════════════════════ */

.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: flex-start;
    padding: 0 50px;
    position: relative;
    overflow: hidden;
    max-width: 1400px;
    margin: 0 auto;
}

.hero-bg-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(ellipse at 20% 50%, rgba(100, 255, 218, 0.03) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 20%, rgba(100, 255, 218, 0.02) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
}

.hero-particles {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    pointer-events: none;
    z-index: 0;
}

.particle {
    position: absolute;
    width: 3px;
    height: 3px;
    background: var(--accent);
    border-radius: 50%;
    opacity: 0;
    animation: float-up linear infinite;
}

@keyframes float-up {
    0% {
        opacity: 0;
        transform: translateY(100vh) scale(0);
    }
    10% {
        opacity: 0.6;
    }
    90% {
        opacity: 0.2;
    }
    100% {
        opacity: 0;
        transform: translateY(-100px) scale(1);
    }
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 900px;
}

.hero-greeting {
    font-family: var(--font-mono);
    font-size: 1rem;
    color: var(--accent);
    margin-bottom: 20px;
    letter-spacing: 1px;
}

.hero-name {
    font-size: clamp(40px, 8vw, 80px);
    font-weight: 800;
    color: var(--lightest);
    line-height: 1.2;
    margin-bottom: 10px;
    padding-top: 5px;
    padding-bottom: 5px;
    background: linear-gradient(135deg, var(--lightest) 0%, var(--slate-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-name .accent {
    -webkit-text-fill-color: var(--accent);
}

.hero-tagline {
    font-size: clamp(24px, 5vw, 52px);
    font-weight: 700;
    color: var(--slate);
    line-height: 1.2;
    margin-bottom: 25px;
}

.hero-description {
    font-size: 1.05rem;
    line-height: 1.7;
    color: var(--slate);
    max-width: 580px;
    margin-bottom: 35px;
}

.hero-description strong {
    color: var(--lightest);
}

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

.hero-cta {
    display: flex;
    gap: 20px;
    margin-bottom: 60px;
}

.btn {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    padding: 14px 28px;
    border-radius: 4px;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    letter-spacing: 0.5px;
}

.btn-primary {
    background-color: transparent;
    border: 1px solid var(--accent);
    color: var(--accent);
}

.btn-primary:hover {
    background-color: var(--accent-dim);
    transform: translateY(-2px);
    box-shadow: 0 4px 20px var(--accent-glow);
}

.btn-outline {
    background-color: transparent;
    border: 1px solid var(--accent);
    color: var(--accent);
}

.btn-outline:hover {
    background-color: var(--accent-dim);
    transform: translateY(-2px);
}

.btn-large {
    padding: 18px 40px;
    font-size: 1rem;
}

/* Hero Stats */
.hero-stats {
    display: flex;
    gap: 50px;
}

.stat {
    text-align: center;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--accent);
    display: inline-block;
    line-height: 1;
}

.stat-plus {
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent);
    display: inline-block;
}

.stat-label {
    font-size: 0.8rem;
    color: var(--slate);
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-top: 4px;
    display: block;
    font-family: var(--font-mono);
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1;
}

.mouse {
    width: 26px;
    height: 40px;
    border: 2px solid var(--slate);
    border-radius: 13px;
    display: flex;
    justify-content: center;
    padding-top: 6px;
    opacity: 0.5;
    transition: var(--transition);
}

.mouse:hover { opacity: 1; border-color: var(--accent); }

.wheel {
    width: 3px;
    height: 8px;
    background: var(--accent);
    border-radius: 2px;
    animation: scroll-wheel 2s ease-in-out infinite;
}

@keyframes scroll-wheel {
    0%   { opacity: 1; transform: translateY(0); }
    100% { opacity: 0; transform: translateY(12px); }
}

/* Animate In */
.animate-in {
    opacity: 0;
    transform: translateY(25px);
    animation: fadeInUp 0.6s ease forwards;
}

.delay-1 { animation-delay: 0.2s; }
.delay-2 { animation-delay: 0.4s; }
.delay-3 { animation-delay: 0.6s; }
.delay-4 { animation-delay: 0.8s; }

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

/* ═══════════════════════════════════════════
   Section Titles
   ═══════════════════════════════════════════ */

.section {
    padding: var(--section-padding);
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--lightest);
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 15px;
    white-space: nowrap;
}

.section-title::after {
    content: '';
    display: block;
    width: 300px;
    height: 1px;
    background: var(--navy-lighter);
    flex-shrink: 1;
}

.section-number {
    font-family: var(--font-mono);
    font-size: 1.2rem;
    font-weight: 400;
    color: var(--accent);
}

.section-subtitle {
    color: var(--slate);
    font-size: 1rem;
    margin-bottom: 50px;
    max-width: 600px;
}

/* ═══════════════════════════════════════════
   About Section
   ═══════════════════════════════════════════ */

.about-grid {
    display: grid;
    grid-template-columns: 3fr 2fr;
    gap: 60px;
    align-items: start;
    margin-top: 40px;
}

.about-text p {
    margin-bottom: 18px;
    font-size: 1rem;
    line-height: 1.7;
}

.about-text strong {
    color: var(--lightest);
}

.tech-list {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 6px 10px;
    list-style: none;
    margin-top: 20px;
}

.tech-list li {
    font-family: var(--font-mono);
    font-size: 0.82rem;
    color: var(--slate-light);
    position: relative;
    padding-left: 20px;
}

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

/* Profile Image */
.image-wrapper {
    position: relative;
    max-width: 300px;
    margin: 0 auto;
}

.image-wrapper img {
    border-radius: 8px;
    filter: grayscale(30%) contrast(1.05);
    transition: var(--transition);
    position: relative;
    z-index: 2;
}

.image-wrapper:hover img {
    filter: none;
}

.image-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--accent);
    mix-blend-mode: multiply;
    border-radius: 8px;
    opacity: 0.15;
    transition: var(--transition);
    z-index: 3;
}

.image-wrapper:hover .image-overlay {
    opacity: 0;
}

.image-wrapper::after {
    content: '';
    position: absolute;
    top: 15px;
    left: 15px;
    right: -15px;
    bottom: -15px;
    border: 2px solid var(--accent);
    border-radius: 8px;
    z-index: 1;
    transition: var(--transition);
}

.image-wrapper:hover::after {
    top: 10px;
    left: 10px;
}

/* ═══════════════════════════════════════════
   Experience Section
   ═══════════════════════════════════════════ */

.experience-container {
    display: flex;
    gap: 30px;
    margin-top: 40px;
}

.exp-tabs {
    display: flex;
    flex-direction: column;
    min-width: 200px;
    border-left: 2px solid var(--navy-lighter);
    position: relative;
}

.exp-tab {
    font-family: var(--font-mono);
    font-size: 0.82rem;
    background: none;
    border: none;
    color: var(--slate);
    padding: 12px 20px;
    text-align: left;
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
    position: relative;
}

.exp-tab:hover {
    color: var(--accent);
    background-color: var(--accent-dim);
}

.exp-tab.active {
    color: var(--accent);
}

.exp-tab.active::before {
    content: '';
    position: absolute;
    left: -2px;
    top: 0;
    height: 100%;
    width: 2px;
    background: var(--accent);
}

.exp-panel {
    display: none;
}

.exp-panel.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(5px); }
    to { opacity: 1; transform: translateY(0); }
}

.exp-title {
    font-size: 1.25rem;
    color: var(--lightest);
    font-weight: 600;
    margin-bottom: 5px;
}

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

.exp-date {
    font-family: var(--font-mono);
    font-size: 0.82rem;
    color: var(--slate);
    margin-bottom: 5px;
}

.exp-date i { margin-right: 6px; color: var(--accent); }

.exp-project {
    font-size: 0.9rem;
    color: var(--slate-light);
    margin-bottom: 20px;
    font-style: italic;
}

.exp-project i { margin-right: 6px; color: var(--accent); }

.funding-badge {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-style: normal;
    background: var(--accent-dim);
    color: var(--accent);
    padding: 2px 10px;
    border-radius: 12px;
    border: 1px solid rgba(100, 255, 218, 0.2);
    margin-left: 8px;
    vertical-align: middle;
}

.exp-list {
    list-style: none;
}

.exp-list li {
    position: relative;
    padding-left: 25px;
    margin-bottom: 12px;
    font-size: 0.95rem;
    line-height: 1.6;
}

.exp-list li::before {
    content: '▹';
    color: var(--accent);
    position: absolute;
    left: 0;
    font-size: 1.1rem;
}

/* ═══════════════════════════════════════════
   Publications Section
   ═══════════════════════════════════════════ */

.pub-filter {
    display: flex;
    gap: 10px;
    margin-bottom: 35px;
    flex-wrap: wrap;
}

.pub-filter-btn {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    background: none;
    border: 1px solid var(--navy-lighter);
    color: var(--slate);
    padding: 8px 20px;
    border-radius: 20px;
    cursor: pointer;
    transition: var(--transition);
}

.pub-filter-btn:hover,
.pub-filter-btn.active {
    border-color: var(--accent);
    color: var(--accent);
    background-color: var(--accent-dim);
}

.pub-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.pub-card {
    display: flex;
    gap: 20px;
    padding: 24px;
    background: var(--navy-light);
    border-radius: 8px;
    border: 1px solid transparent;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.pub-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 3px;
    height: 100%;
    background: var(--accent);
    opacity: 0;
    transition: var(--transition);
}

.pub-card:hover {
    border-color: var(--navy-lighter);
    transform: translateX(5px);
    box-shadow: -5px 0 20px rgba(100, 255, 218, 0.05);
}

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

.pub-year {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--accent);
    font-weight: 600;
    min-width: 50px;
    padding-top: 2px;
}

.pub-info {
    flex: 1;
}

.pub-badge {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 0.65rem;
    padding: 3px 10px;
    border-radius: 3px;
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 600;
}

.pub-badge.submitted {
    background: rgba(255, 215, 0, 0.12);
    color: var(--gold);
    border: 1px solid rgba(255, 215, 0, 0.3);
}

.pub-badge.nature {
    background: rgba(255, 107, 107, 0.12);
    color: var(--danger);
    border: 1px solid rgba(255, 107, 107, 0.3);
}

.pub-badge.journal {
    background: rgba(96, 165, 250, 0.12);
    color: var(--blue);
    border: 1px solid rgba(96, 165, 250, 0.3);
}

.pub-badge.conference {
    background: rgba(167, 139, 250, 0.12);
    color: var(--purple);
    border: 1px solid rgba(167, 139, 250, 0.3);
}

.pub-title {
    font-size: 1rem;
    color: var(--lightest);
    font-weight: 600;
    margin-bottom: 6px;
    line-height: 1.4;
}

.pub-title a {
    color: var(--lightest);
}

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

.pub-authors {
    font-size: 0.85rem;
    color: var(--slate);
    margin-bottom: 4px;
}

.pub-authors strong {
    color: var(--accent);
}

.pub-journal {
    font-size: 0.82rem;
    color: var(--slate);
    font-style: italic;
}

.pub-journal i {
    margin-right: 5px;
    color: var(--accent);
    opacity: 0.6;
}

.pub-cta {
    text-align: center;
    margin-top: 40px;
}

/* Hide filtered items */
.pub-card.hidden {
    display: none;
}

/* ═══════════════════════════════════════════
   Skills Section
   ═══════════════════════════════════════════ */

.skills-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-top: 40px;
}

.skill-card {
    background: var(--navy-light);
    border: 1px solid var(--navy-lighter);
    border-radius: 8px;
    padding: 30px 25px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.skill-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--accent), transparent);
    opacity: 0;
    transition: var(--transition);
}

.skill-card:hover {
    transform: translateY(-5px);
    border-color: var(--accent);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

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

.skill-icon {
    font-size: 2rem;
    color: var(--accent);
    margin-bottom: 18px;
}

.skill-card h3 {
    font-size: 1.1rem;
    color: var(--lightest);
    margin-bottom: 15px;
    font-weight: 600;
}

.skill-card ul {
    list-style: none;
}

.skill-card li {
    font-size: 0.85rem;
    color: var(--slate);
    padding: 4px 0;
    padding-left: 16px;
    position: relative;
}

.skill-card li::before {
    content: '›';
    color: var(--accent);
    position: absolute;
    left: 0;
    font-weight: bold;
}

/* ═══════════════════════════════════════════
   Education Section
   ═══════════════════════════════════════════ */

.education {
    padding-bottom: 60px;
}

.edu-timeline {
    display: flex;
    flex-direction: column;
    gap: 25px;
    margin-top: 40px;
    position: relative;
    padding-left: 30px;
}

.edu-timeline::before {
    content: '';
    position: absolute;
    left: 12px;
    top: 5px;
    bottom: 5px;
    width: 2px;
    background: linear-gradient(to bottom, var(--accent), var(--navy-lighter));
}

.edu-card {
    display: flex;
    gap: 20px;
    align-items: flex-start;
    position: relative;
}

.edu-icon {
    width: 40px;
    height: 40px;
    background: var(--navy);
    border: 2px solid var(--accent);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent);
    font-size: 0.9rem;
    flex-shrink: 0;
    position: relative;
    z-index: 1;
    margin-left: -18px;
}

.edu-details h3 {
    font-size: 1.1rem;
    color: var(--lightest);
    font-weight: 600;
    margin-bottom: 4px;
}

.edu-school {
    font-size: 0.95rem;
    color: var(--slate);
}

.edu-year {
    font-family: var(--font-mono);
    font-size: 0.82rem;
    color: var(--accent);
    margin-top: 2px;
}

/* ═══════════════════════════════════════════
   Contact Section
   ═══════════════════════════════════════════ */

.contact {
    text-align: center;
    padding-bottom: 80px;
}

.contact .section-title {
    justify-content: center;
}

.contact .section-title::after {
    display: none;
}

.contact-content {
    max-width: 650px;
    margin: 0 auto;
}

.contact-text {
    font-size: 1.05rem;
    line-height: 1.7;
    margin-bottom: 40px;
    margin-top: 20px;
}

.contact-cards {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 15px;
    margin-bottom: 40px;
}

.contact-card {
    background: var(--navy-light);
    border: 1px solid var(--navy-lighter);
    border-radius: 8px;
    padding: 25px 15px;
    transition: var(--transition);
    color: var(--slate);
    text-decoration: none;
}

.contact-card:hover {
    border-color: var(--accent);
    transform: translateY(-3px);
    background: rgba(100, 255, 218, 0.03);
}

.contact-card i {
    font-size: 1.6rem;
    color: var(--accent);
    margin-bottom: 12px;
}

.contact-card h4 {
    color: var(--lightest);
    font-size: 0.9rem;
    margin-bottom: 6px;
}

.contact-card p {
    font-size: 0.78rem;
    font-family: var(--font-mono);
    color: var(--slate);
}

/* ═══════════════════════════════════════════
   Footer
   ═══════════════════════════════════════════ */

.footer {
    text-align: center;
    padding: 30px 20px;
}

.footer-social {
    display: flex;
    justify-content: center;
    gap: 25px;
    margin-bottom: 20px;
}

.footer-social a {
    color: var(--slate);
    font-size: 1.3rem;
    transition: var(--transition);
}

.footer-social a:hover {
    color: var(--accent);
    transform: translateY(-3px);
}

.footer-text {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    color: var(--slate);
    margin-bottom: 5px;
}

.footer-copyright {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    color: var(--navy-lighter);
}

/* ═══════════════════════════════════════════
   Side Elements (Desktop Only)
   ═══════════════════════════════════════════ */

.side-email,
.side-social {
    position: fixed;
    bottom: 0;
    z-index: 10;
}

.side-email {
    right: 40px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.side-email a {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--slate);
    writing-mode: vertical-rl;
    letter-spacing: 2px;
    transition: var(--transition);
    padding-bottom: 20px;
}

.side-email a:hover {
    color: var(--accent);
    transform: translateY(-3px);
}

.side-email::after {
    content: '';
    display: block;
    width: 1px;
    height: 90px;
    background: var(--slate);
}

.side-social {
    left: 40px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.side-social a {
    color: var(--slate);
    font-size: 1.1rem;
    transition: var(--transition);
}

.side-social a:hover {
    color: var(--accent);
    transform: translateY(-3px);
}

.side-social::after {
    content: '';
    display: block;
    width: 1px;
    height: 90px;
    background: var(--slate);
}

/* ═══════════════════════════════════════════
   Scroll Reveal Animations
   ═══════════════════════════════════════════ */

.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ═══════════════════════════════════════════
   Responsive Design
   ═══════════════════════════════════════════ */

@media (max-width: 1080px) {
    .skills-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .navbar { padding: 15px 25px; }
    .navbar.scrolled { padding: 10px 25px; }
    
    .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 70%;
        max-width: 300px;
        height: 100vh;
        background: var(--navy-light);
        flex-direction: column;
        justify-content: center;
        padding: 40px;
        transition: var(--transition-slow);
        box-shadow: -10px 0 30px rgba(0, 0, 0, 0.5);
    }

    .nav-links.active { right: 0; }
    .nav-toggle { display: block; z-index: 1001; }
    .btn-resume { margin-left: 0; }

    .hero { padding: 0 25px; }
    .hero-stats { gap: 25px; flex-wrap: wrap; }
    .stat-number { font-size: 2rem; }

    .about-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    .about-image { order: -1; }
    .image-wrapper { max-width: 250px; }

    .experience-container {
        flex-direction: column;
    }
    .exp-tabs {
        flex-direction: row;
        overflow-x: auto;
        border-left: none;
        border-bottom: 2px solid var(--navy-lighter);
        min-width: unset;
    }
    .exp-tab.active::before {
        left: 0;
        top: unset;
        bottom: -2px;
        height: 2px;
        width: 100%;
    }

    .skills-grid { grid-template-columns: 1fr; }
    .contact-cards { grid-template-columns: repeat(2, 1fr); }
    
    .side-email, .side-social { display: none; }

    .section-title::after { width: 100px; }
}

@media (max-width: 480px) {
    .hero-cta {
        flex-direction: column;
        align-items: flex-start;
    }
    .hero-stats { gap: 20px; }
    .contact-cards { grid-template-columns: 1fr; }
    .pub-card { flex-direction: column; gap: 8px; }
    .tech-list { grid-template-columns: 1fr; }
}

/* ═══════════════════════════════════════════
   Print Styles
   ═══════════════════════════════════════════ */

@media print {
    .navbar, .hero-particles, .side-email, .side-social,
    .scroll-indicator, .hero-bg-overlay { display: none; }
    
    body {
        background: white;
        color: #333;
    }
    
    .hero { min-height: auto; padding: 20px; }
    .section { padding: 30px 0; }
}