/* ==========================================
   CSS Variables & Reset
   ========================================== */
:root {
    --color-primary: #1a1a2e;
    --color-secondary: #16213e;
    --color-accent: #e94560;
    --color-accent-light: #ff6b6b;
    --color-text: #333;
    --color-text-light: #666;
    --color-text-muted: #999;
    --color-bg: #ffffff;
    --color-bg-alt: #f8f9fa;
    --color-border: #e9ecef;

    --font-heading: 'Cormorant Garamond', Georgia, serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;

    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 8rem;

    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.12);
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-body);
    color: var(--color-text);
    background-color: var(--color-bg);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ==========================================
   Typography
   ========================================== */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 600;
    line-height: 1.3;
    color: var(--color-primary);
}

h1 { font-size: clamp(2.5rem, 5vw, 4rem); }
h2 { font-size: clamp(2rem, 4vw, 3rem); }
h3 { font-size: clamp(1.25rem, 2vw, 1.5rem); }
h4 { font-size: 1.125rem; }

p { margin-bottom: 1rem; }

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

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

.lead {
    font-size: 1.25rem;
    color: var(--color-text-light);
    line-height: 1.8;
}

/* ==========================================
   Layout
   ========================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.section {
    padding: var(--spacing-xl) 0;
}

.section-header {
    margin-bottom: var(--spacing-lg);
    display: flex;
    align-items: baseline;
    gap: var(--spacing-sm);
}

.section-number {
    font-family: var(--font-body);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-accent);
    letter-spacing: 0.1em;
}

.section-title {
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -0.5rem;
    left: 0;
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, var(--color-accent), var(--color-accent-light));
    border-radius: 2px;
}

/* ==========================================
   Navigation
   ========================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
    transition: var(--transition);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-primary);
}

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

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
}

.nav-link {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-text-light);
    padding: 0.5rem 0;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-accent);
    transition: var(--transition);
}

.nav-link:hover {
    color: var(--color-primary);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-link.active {
    color: var(--color-primary);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.nav-toggle span {
    width: 25px;
    height: 2px;
    background: var(--color-primary);
    transition: var(--transition);
}

/* ==========================================
   Hero Section
   ========================================== */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: calc(70px + var(--spacing-lg)) var(--spacing-md) var(--spacing-lg);
    background: linear-gradient(135deg, #f8f9fa 0%, #fff 50%, #f0f4f8 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 80%;
    height: 150%;
    background: radial-gradient(ellipse, rgba(233, 69, 96, 0.03) 0%, transparent 70%);
    pointer-events: none;
}

.hero-content {
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: var(--spacing-lg);
    align-items: center;
}

.hero-subtitle {
    font-size: 0.875rem;
    font-weight: 500;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--color-accent);
    margin-bottom: var(--spacing-sm);
}

.hero-title {
    font-size: clamp(3rem, 6vw, 5rem);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-description {
    font-size: 1.25rem;
    color: var(--color-text-light);
    max-width: 500px;
    margin-bottom: var(--spacing-md);
}

.hero-affiliation {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-text-muted);
    font-size: 1rem;
    margin-bottom: var(--spacing-md);
}

.affiliation-icon {
    color: var(--color-accent);
}

.hero-cta {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

/* Academic Profile Badges */
.academic-profiles {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-md);
}

.profile-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 0.5rem 1rem;
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: 50px;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--color-text-light);
    transition: var(--transition);
}

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

.profile-badge.orcid:hover {
    border-color: #a6ce39;
    color: #a6ce39;
}

.profile-badge.repec:hover {
    border-color: #2a5885;
    color: #2a5885;
}

.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.image-frame {
    position: relative;
    width: 320px;
    height: 400px;
}

.image-frame::before {
    content: '';
    position: absolute;
    top: 20px;
    left: 20px;
    right: -20px;
    bottom: -20px;
    border: 3px solid var(--color-accent);
    border-radius: 8px;
    z-index: -1;
}

.image-placeholder {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--color-bg-alt), #e9ecef);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    color: var(--color-text-muted);
    box-shadow: var(--shadow-lg);
}

.profile-photo {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 8px;
    box-shadow: var(--shadow-lg);
}

.hero-scroll {
    position: absolute;
    bottom: var(--spacing-md);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-text-muted);
    font-size: 0.75rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

.scroll-line {
    width: 1px;
    height: 60px;
    background: linear-gradient(to bottom, var(--color-accent), transparent);
    animation: scrollPulse 2s infinite;
}

@keyframes scrollPulse {
    0%, 100% { opacity: 1; transform: scaleY(1); }
    50% { opacity: 0.5; transform: scaleY(0.8); }
}

/* ==========================================
   Buttons
   ========================================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 0.875rem 1.75rem;
    font-size: 0.9rem;
    font-weight: 500;
    border-radius: 6px;
    transition: var(--transition);
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-accent), var(--color-accent-light));
    color: white;
    box-shadow: 0 4px 15px rgba(233, 69, 96, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(233, 69, 96, 0.4);
    color: white;
}

.btn-secondary {
    background: transparent;
    color: var(--color-primary);
    border: 2px solid var(--color-border);
}

.btn-secondary:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1rem;
}

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

.about-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: var(--spacing-lg);
}

.about-text p {
    color: var(--color-text-light);
}

.research-interests {
    margin-top: var(--spacing-md);
}

.research-interests h3 {
    font-size: 1rem;
    font-family: var(--font-body);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
}

.interest-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    list-style: none;
}

.interest-tags li {
    padding: 0.5rem 1rem;
    background: var(--color-bg-alt);
    border-radius: 50px;
    font-size: 0.875rem;
    color: var(--color-text-light);
    border: 1px solid var(--color-border);
    transition: var(--transition);
}

.interest-tags li:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
}

.about-education h3 {
    font-size: 1rem;
    font-family: var(--font-body);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
}

.education-timeline {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.education-item {
    display: flex;
    gap: var(--spacing-md);
}

.edu-year {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-accent);
    min-width: 50px;
}

.edu-details h4 {
    font-family: var(--font-body);
    font-size: 1rem;
    margin-bottom: 0.25rem;
}

.edu-details p {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    margin: 0;
}

/* ==========================================
   Research Section
   ========================================== */
.research {
    background: var(--color-bg-alt);
}

.research-category h3 {
    font-family: var(--font-body);
    font-size: 1rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-md);
}

.paper-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.paper {
    background: var(--color-bg);
    padding: var(--spacing-md);
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border-left: 4px solid transparent;
    position: relative;
}

.paper:hover {
    box-shadow: var(--shadow-md);
    border-left-color: var(--color-accent);
    transform: translateX(5px);
}

/* Paper Status Badges */
.paper-status {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border-radius: 50px;
    margin-bottom: var(--spacing-sm);
}

.paper-status.published {
    background: #d4edda;
    color: #155724;
}

.paper-status.forthcoming {
    background: #e8daef;
    color: #6c3483;
}

.paper-status.rr {
    background: #fff3cd;
    color: #856404;
}

.paper-status.submitted {
    background: #cce5ff;
    color: #004085;
}

.paper-status.wip {
    background: #e2e3e5;
    color: #383d41;
}

.paper-title {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xs);
}

.paper-authors {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    margin-bottom: 0.25rem;
}

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

.coauthor-link:hover {
    text-decoration: underline;
}

.paper-venue {
    font-size: 0.875rem;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-xs);
}

.paper-abstract {
    font-size: 0.9rem;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-sm);
}

.paper-links {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.paper-link {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--color-accent);
    padding: 0.375rem 0.75rem;
    background: rgba(233, 69, 96, 0.08);
    border-radius: 4px;
    transition: var(--transition);
}

.paper-link:hover {
    background: var(--color-accent);
    color: white;
}

.paper-link svg {
    flex-shrink: 0;
}

.research-category + .research-category {
    margin-top: var(--spacing-lg);
}

/* ==========================================
   Teaching Section
   ========================================== */
.teaching {
    background: var(--color-bg);
}

.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-md);
}

.course-card {
    background: var(--color-bg-alt);
    padding: var(--spacing-md);
    border-radius: 12px;
    text-align: center;
    transition: var(--transition);
    border: 1px solid var(--color-border);
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
    border-color: var(--color-accent);
}

.course-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto var(--spacing-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--color-accent), var(--color-accent-light));
    border-radius: 50%;
    color: white;
}

.teaching-intro {
    max-width: 700px;
    margin-bottom: var(--spacing-md);
}

.teaching-intro p {
    color: var(--color-text-light);
    margin: 0;
}

.course-card h4 {
    font-family: var(--font-body);
    margin-bottom: 0.25rem;
}

.course-level {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-accent);
    margin-bottom: var(--spacing-xs);
}

.course-card p {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    margin: 0 0 var(--spacing-sm) 0;
}

.course-syllabus {
    display: inline-block;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--color-accent);
    padding: 0.375rem 0.75rem;
    border: 1px solid var(--color-accent);
    border-radius: 4px;
    transition: var(--transition);
}

.course-syllabus:hover {
    background: var(--color-accent);
    color: white;
}

/* ==========================================
   Media Section
   ========================================== */
.media {
    background: var(--color-bg-alt);
}

.media-intro {
    color: var(--color-text-light);
    max-width: 600px;
    margin-bottom: var(--spacing-md);
}

.media-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
}

.media-card {
    background: var(--color-bg);
    padding: var(--spacing-md);
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
}

.media-type {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-accent);
    margin-bottom: var(--spacing-xs);
}

.media-card h4 {
    font-family: var(--font-body);
    margin-bottom: var(--spacing-xs);
}

.media-card p {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    margin: 0;
}

/* ==========================================
   CV Section
   ========================================== */
.cv {
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    color: white;
    text-align: center;
}

.cv .section-number {
    color: rgba(255, 255, 255, 0.5);
}

.cv .section-title {
    color: white;
}

.cv .section-title::after {
    left: 50%;
    transform: translateX(-50%);
}

.cv-content {
    max-width: 600px;
    margin: 0 auto;
}

.cv-content p {
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: var(--spacing-md);
}

.cv-buttons {
    margin-bottom: var(--spacing-sm);
}

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

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

.cv-updated {
    font-size: 0.8rem;
    color: rgba(255, 255, 255, 0.5);
    margin: 0;
}

/* ==========================================
   Contact Section
   ========================================== */
.contact {
    background: var(--color-bg);
}

.contact-content {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
}

.contact-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-bg-alt);
    border-radius: 50%;
    color: var(--color-accent);
}

.contact-item h4 {
    font-family: var(--font-body);
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.contact-item p,
.contact-item a {
    font-size: 0.9rem;
    color: var(--color-text-light);
    margin: 0;
}

.contact-social {
    display: flex;
    gap: var(--spacing-sm);
}

.social-link {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-bg-alt);
    border-radius: 50%;
    color: var(--color-text-light);
    transition: var(--transition);
}

.social-link:hover {
    background: var(--color-accent);
    color: white;
    transform: translateY(-3px);
}

/* Contact Profile Links */
.contact-profiles {
    flex: 1;
}

.contact-profiles h4 {
    font-family: var(--font-body);
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
}

.profile-links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.profile-link-item {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 0.625rem 1rem;
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    font-size: 0.875rem;
    color: var(--color-text-light);
    transition: var(--transition);
}

.profile-link-item:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
    transform: translateX(5px);
}

.profile-link-item svg {
    flex-shrink: 0;
}

/* ==========================================
   Footer
   ========================================== */
.footer {
    background: var(--color-primary);
    color: rgba(255, 255, 255, 0.6);
    padding: var(--spacing-md) 0;
    text-align: center;
    font-size: 0.875rem;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-content p {
    margin: 0;
}

.footer-domain {
    font-weight: 500;
    color: rgba(255, 255, 255, 0.8);
}

/* ==========================================
   Responsive Design
   ========================================== */
@media (max-width: 992px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-description {
        margin-left: auto;
        margin-right: auto;
    }

    .hero-affiliation {
        justify-content: center;
    }

    .academic-profiles {
        justify-content: center;
    }

    .hero-cta {
        justify-content: center;
    }

    .hero-image {
        order: -1;
    }

    .image-frame {
        width: 250px;
        height: 300px;
    }

    .about-content {
        grid-template-columns: 1fr;
    }

    .footer-content {
        flex-direction: column;
        gap: var(--spacing-xs);
    }
}

@media (max-width: 768px) {
    :root {
        --spacing-lg: 3rem;
        --spacing-xl: 5rem;
    }

    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: var(--spacing-md);
        gap: 0;
        box-shadow: var(--shadow-md);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-link {
        padding: var(--spacing-sm) 0;
        border-bottom: 1px solid var(--color-border);
    }

    .nav-toggle {
        display: flex;
    }

    .section-header {
        flex-direction: column;
        gap: var(--spacing-xs);
    }

    .hero-scroll {
        display: none;
    }

    .contact-content {
        flex-direction: column;
    }

    .profile-links {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
    }

    .paper-links {
        flex-direction: column;
        align-items: flex-start;
    }
}

@media (max-width: 480px) {
    .hero-cta {
        flex-direction: column;
        width: 100%;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }

    .image-frame {
        width: 200px;
        height: 250px;
    }
}