/* ===== CSS Variables & Theme ===== */
:root {
    --bg-primary: #faf9f7;
    --bg-secondary: #ffffff;
    --bg-glass: rgba(255, 255, 255, 0.7);
    --text-primary: #2d2a26;
    --text-secondary: #5c5752;
    --text-muted: #8a857d;
    --accent: #7c6a5d;
    --accent-light: #a69485;
    --accent-glow: rgba(124, 106, 93, 0.3);
    --border: rgba(124, 106, 93, 0.15);
    --shadow: 0 4px 24px rgba(45, 42, 38, 0.08);
    --shadow-hover: 0 8px 32px rgba(45, 42, 38, 0.12);
    --gradient: linear-gradient(135deg, #f5f0eb 0%, #e8e2db 100%);
}

[data-theme="dark"] {
    --bg-primary: #1a1918;
    --bg-secondary: #242220;
    --bg-glass: rgba(36, 34, 32, 0.8);
    --text-primary: #f5f0eb;
    --text-secondary: #c4bdb4;
    --text-muted: #8a857d;
    --accent: #c4a98a;
    --accent-light: #d4bfa6;
    --accent-glow: rgba(196, 169, 138, 0.3);
    --border: rgba(196, 169, 138, 0.15);
    --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
    --shadow-hover: 0 8px 32px rgba(0, 0, 0, 0.4);
    --gradient: linear-gradient(135deg, #242220 0%, #1a1918 100%);
}

/* ===== Base Styles ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

/* Safe area insets for notched phones */
@supports (padding: max(0px)) {
    .navbar {
        padding-top: max(0px, env(safe-area-inset-top));
    }
    
    .footer {
        padding-bottom: max(32px, env(safe-area-inset-bottom));
    }
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.7;
    font-size: 16px;
    transition: background 0.4s ease, color 0.4s ease;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Typography ===== */
h1, h2, h3 {
    font-weight: 600;
    line-height: 1.3;
    color: var(--text-primary);
}

h1 { font-size: clamp(2.5rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.75rem, 3vw, 2.25rem); }
h3 { font-size: 1.15rem; }

p {
    color: var(--text-secondary);
}

/* ===== Navigation ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--bg-glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    transition: all 0.3s ease;
}

.nav-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 16px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--accent);
    text-decoration: none;
    letter-spacing: -0.5px;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 32px;
    align-items: center;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width 0.3s ease;
}

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

.nav-links a:hover::after {
    width: 100%;
}

/* Theme Toggle */
.theme-toggle {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    transition: all 0.3s ease;
}

.theme-toggle:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-primary);
    cursor: pointer;
}

/* ===== Hero Section ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 120px 24px 80px;
    background: var(--gradient);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 80%;
    height: 150%;
    background: radial-gradient(circle, var(--accent-glow) 0%, transparent 60%);
    opacity: 0.5;
    pointer-events: none;
}

.hero-container {
    max-width: 1100px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-content {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s ease forwards;
}

.hero-greeting {
    font-size: 1rem;
    color: var(--accent);
    font-weight: 500;
    margin-bottom: 8px;
    letter-spacing: 1px;
    text-transform: uppercase;
}

.hero-name {
    margin-bottom: 16px;
    letter-spacing: -1px;
}

.hero-title {
    font-size: 1.1rem;
    color: var(--accent);
    font-weight: 500;
    margin-bottom: 24px;
}

.hero-description {
    font-size: 1.1rem;
    margin-bottom: 32px;
    max-width: 480px;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
}

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

.btn-primary:hover {
    background: var(--accent-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.btn-secondary {
    background: var(--bg-glass);
    color: var(--text-primary);
    border: 1px solid var(--border);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: var(--bg-secondary);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

/* Hero Image */
.hero-image {
    display: flex;
    justify-content: center;
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s ease 0.2s forwards;
}

.profile-photo-wrapper {
    position: relative;
}

.profile-photo-wrapper::before {
    content: '';
    position: absolute;
    inset: -8px;
    border-radius: 20px;
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-light) 100%);
    opacity: 0.2;
    z-index: -1;
    transition: all 0.4s ease;
}

.profile-photo-wrapper:hover::before {
    inset: -12px;
    opacity: 0.3;
}

.profile-photo {
    width: 320px;
    height: 400px;
    object-fit: cover;
    border-radius: 16px;
    box-shadow: var(--shadow-hover);
    transition: transform 0.4s ease;
}

.profile-photo:hover {
    transform: scale(1.02);
}

/* ===== Section Styles ===== */
.section {
    padding: 100px 0;
}

.section-title {
    text-align: center;
    margin-bottom: 60px;
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 40px;
    height: 3px;
    background: var(--accent);
    margin: 16px auto 0;
    border-radius: 2px;
}

/* Scroll Animations */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ===== About Section ===== */
.about {
    background: var(--bg-secondary);
}

.about-content {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 60px;
    align-items: start;
}

.about-text p {
    margin-bottom: 20px;
    font-size: 1.05rem;
}

.skills-grid {
    display: flex;
    flex-direction: column;
    gap: 32px;
}

.skill-category {
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 24px;
    transition: all 0.3s ease;
}

.skill-category:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.skill-category h3 {
    color: var(--accent);
    margin-bottom: 16px;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

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

.skill-category li {
    padding: 8px 0;
    color: var(--text-secondary);
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    gap: 10px;
}

.skill-category li::before {
    content: '';
    width: 6px;
    height: 6px;
    background: var(--accent);
    border-radius: 50%;
    flex-shrink: 0;
}

/* ===== Experience Section ===== */
.experience {
    background: var(--bg-primary);
}

.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border);
}

.timeline-item {
    position: relative;
    padding-left: 40px;
    padding-bottom: 48px;
}

.timeline-item:last-child {
    padding-bottom: 0;
}

.timeline-marker {
    position: absolute;
    left: -5px;
    top: 4px;
    width: 12px;
    height: 12px;
    background: var(--accent);
    border-radius: 50%;
    border: 3px solid var(--bg-primary);
}

.timeline-content {
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 28px;
    transition: all 0.3s ease;
}

.timeline-content:hover {
    transform: translateX(8px);
    box-shadow: var(--shadow-hover);
}

.timeline-date {
    display: inline-block;
    font-size: 0.85rem;
    color: var(--accent);
    font-weight: 500;
    margin-bottom: 8px;
}

.timeline-content h3 {
    margin-bottom: 4px;
}

.company {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: 16px;
}

.timeline-content ul {
    list-style: none;
}

.timeline-content li {
    padding: 6px 0;
    padding-left: 20px;
    position: relative;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.timeline-content li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--accent);
}

/* Stat highlights */
.stat {
    display: inline-block;
    color: var(--accent);
    font-weight: 600;
}

/* ===== Education Section ===== */
.education {
    background: var(--bg-secondary);
}

.education-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
    margin-bottom: 60px;
}

.education-card {
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 32px;
    transition: all 0.3s ease;
}

.education-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
}

.education-icon {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.education-card h3 {
    margin-bottom: 8px;
    font-size: 1.1rem;
}

.institution {
    color: var(--accent);
    font-weight: 500;
    margin-bottom: 4px;
}

.date {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 8px;
}

.grade {
    display: inline-block;
    background: var(--accent);
    color: white;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    margin-bottom: 12px;
}

.dissertation {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-style: italic;
}

.subsection-title {
    text-align: center;
    margin-bottom: 32px;
    color: var(--text-primary);
}

.certifications-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: center;
}

.cert-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border);
    padding: 12px 20px;
    border-radius: 30px;
    font-size: 0.9rem;
    color: var(--text-secondary);
    transition: all 0.3s ease;
}

.cert-badge:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
    border-color: var(--accent);
    color: var(--accent);
}

.cert-icon {
    font-size: 1rem;
}

/* ===== Publications Section ===== */
.publications {
    background: var(--bg-primary);
}

.publication-card {
    display: flex;
    gap: 24px;
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 32px;
    max-width: 700px;
    margin: 0 auto;
    transition: all 0.3s ease;
}

.publication-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.publication-icon {
    font-size: 3rem;
    flex-shrink: 0;
}

.publication-content h3 {
    margin-bottom: 8px;
    font-size: 1.15rem;
}

.authors {
    color: var(--accent);
    font-weight: 500;
    margin-bottom: 4px;
}

.journal {
    color: var(--text-muted);
    font-size: 0.95rem;
    font-style: italic;
    margin-bottom: 16px;
}

.publication-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: var(--accent);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: gap 0.3s ease;
}

.publication-link:hover {
    gap: 10px;
}

/* ===== Contact Section ===== */
.contact {
    background: var(--gradient);
    position: relative;
    overflow: hidden;
}

.contact::before {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 60%;
    height: 100%;
    background: radial-gradient(circle, var(--accent-glow) 0%, transparent 60%);
    opacity: 0.4;
    pointer-events: none;
}

.contact .container {
    position: relative;
    z-index: 1;
}

.contact-intro {
    text-align: center;
    font-size: 1.1rem;
    margin-bottom: 48px;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.contact-methods {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    max-width: 800px;
    margin: 0 auto;
}

.contact-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 32px 24px;
    text-decoration: none;
    transition: all 0.3s ease;
}

.contact-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
    border-color: var(--accent);
}

.contact-icon {
    font-size: 2rem;
}

.contact-label {
    font-size: 0.85rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.contact-value {
    color: var(--text-primary);
    font-weight: 500;
    text-align: center;
    font-size: 0.95rem;
}

/* ===== Footer ===== */
.footer {
    background: var(--bg-secondary);
    padding: 32px 0;
    text-align: center;
    border-top: 1px solid var(--border);
}

.footer p {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* ===== Animations ===== */
@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Counter Animation */
.counter {
    display: inline-block;
}

/* ===== Responsive Design ===== */

/* Tablet */
@media (max-width: 900px) {
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 40px;
    }
    
    .hero-content {
        order: 2;
    }
    
    .hero-image {
        order: 1;
    }
    
    .hero-description {
        margin-left: auto;
        margin-right: auto;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .profile-photo {
        width: 250px;
        height: 320px;
    }
    
    .about-content {
        grid-template-columns: 1fr;
    }
    
    .education-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-methods {
        grid-template-columns: 1fr;
        max-width: 400px;
    }
}

/* Mobile Landscape / Small Tablet */
@media (max-width: 768px) {
    body {
        font-size: 15px;
    }
    
    .container {
        padding: 0 20px;
    }
    
    .nav-container {
        padding: 14px 20px;
    }
    
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg-glass);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 24px;
        gap: 16px;
        border-bottom: 1px solid var(--border);
    }
    
    .nav-links.active {
        display: flex;
    }
    
    .nav-links a {
        font-size: 1rem;
        padding: 8px 0;
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .theme-toggle {
        position: absolute;
        right: 70px;
    }
    
    .section {
        padding: 60px 0;
    }
    
    .section-title {
        margin-bottom: 40px;
        font-size: 1.6rem;
    }
    
    .timeline::before {
        left: 6px;
    }
    
    .timeline-item {
        padding-left: 32px;
        padding-bottom: 32px;
    }
    
    .timeline-marker {
        left: 1px;
    }
    
    .timeline-content {
        padding: 20px;
    }
    
    .timeline-content:hover {
        transform: none;
    }
    
    .publication-card {
        flex-direction: column;
        text-align: center;
        padding: 24px;
    }
    
    .education-card {
        padding: 24px;
    }
    
    .education-card:hover {
        transform: none;
    }
    
    .skill-category:hover {
        transform: none;
    }
    
    .contact-card {
        padding: 24px 20px;
    }
    
    .contact-card:hover {
        transform: none;
    }
}

/* Mobile Portrait */
@media (max-width: 480px) {
    body {
        font-size: 14px;
    }
    
    .container {
        padding: 0 16px;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    h2 {
        font-size: 1.5rem;
    }
    
    .hero {
        padding: 90px 16px 50px;
        min-height: auto;
    }
    
    .hero-greeting {
        font-size: 0.85rem;
    }
    
    .hero-title {
        font-size: 0.95rem;
    }
    
    .hero-description {
        font-size: 1rem;
    }
    
    .profile-photo {
        width: 180px;
        height: 230px;
        border-radius: 12px;
    }
    
    .profile-photo-wrapper::before {
        border-radius: 16px;
        inset: -6px;
    }
    
    .hero-buttons {
        flex-direction: column;
        gap: 12px;
        width: 100%;
    }
    
    .btn {
        padding: 14px 24px;
        font-size: 0.95rem;
        width: 100%;
        justify-content: center;
    }
    
    .section {
        padding: 50px 0;
    }
    
    .section-title {
        margin-bottom: 32px;
        font-size: 1.4rem;
    }
    
    .about-text p {
        font-size: 0.95rem;
        margin-bottom: 16px;
    }
    
    .skills-grid {
        gap: 20px;
    }
    
    .skill-category {
        padding: 20px;
        border-radius: 12px;
    }
    
    .skill-category li {
        font-size: 0.9rem;
        padding: 6px 0;
    }
    
    .timeline-content {
        padding: 18px;
        border-radius: 12px;
    }
    
    .timeline-content h3 {
        font-size: 1rem;
    }
    
    .timeline-content li {
        font-size: 0.9rem;
        padding: 5px 0;
        padding-left: 18px;
    }
    
    .company {
        font-size: 0.85rem;
    }
    
    .education-card {
        padding: 20px;
        border-radius: 12px;
    }
    
    .education-icon {
        font-size: 2rem;
        margin-bottom: 12px;
    }
    
    .education-card h3 {
        font-size: 1rem;
    }
    
    .dissertation {
        font-size: 0.85rem;
    }
    
    .subsection-title {
        margin-bottom: 24px;
    }
    
    .certifications-grid {
        flex-direction: column;
        align-items: stretch;
        gap: 10px;
    }
    
    .cert-badge {
        width: 100%;
        justify-content: center;
        padding: 14px 16px;
        font-size: 0.85rem;
        border-radius: 12px;
    }
    
    .publication-card {
        padding: 20px;
        border-radius: 12px;
    }
    
    .publication-icon {
        font-size: 2.5rem;
    }
    
    .publication-content h3 {
        font-size: 1rem;
    }
    
    .journal {
        font-size: 0.85rem;
    }
    
    .contact-intro {
        font-size: 1rem;
        margin-bottom: 32px;
    }
    
    .contact-methods {
        gap: 16px;
    }
    
    .contact-card {
        padding: 20px 16px;
        border-radius: 12px;
    }
    
    .contact-icon {
        font-size: 1.75rem;
    }
    
    .contact-value {
        font-size: 0.9rem;
        word-break: break-all;
    }
    
    .footer {
        padding: 24px 0;
    }
    
    .footer p {
        font-size: 0.8rem;
    }
}

/* Extra small phones */
@media (max-width: 360px) {
    h1 {
        font-size: 1.75rem;
    }
    
    .profile-photo {
        width: 160px;
        height: 200px;
    }
    
    .timeline-item {
        padding-left: 24px;
    }
    
    .timeline-content {
        padding: 16px;
    }
    
    .education-card h3,
    .timeline-content h3,
    .publication-content h3 {
        font-size: 0.95rem;
    }
}

/* Touch device optimizations */
@media (hover: none) {
    .timeline-content:hover,
    .education-card:hover,
    .skill-category:hover,
    .contact-card:hover,
    .cert-badge:hover,
    .publication-card:hover {
        transform: none;
    }
    
    .btn:active {
        transform: scale(0.98);
    }
    
    .contact-card:active {
        background: var(--bg-secondary);
    }
}