/* ===================================
   CSS Variables for Theme Management
   =================================== */
:root {
    /* Light Mode Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-accent: #e9ecef;
    --text-primary: #212529;
    --text-secondary: #6c757d;
    --text-muted: #adb5bd;
    --accent-color: #0066cc;
    --accent-hover: #0052a3;
    --border-color: #dee2e6;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.15);

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-serif: 'Merriweather', Georgia, serif;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
}

/* Dark Mode Colors */
[data-theme="dark"] {
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --bg-accent: #3a3a3a;
    --text-primary: #f8f9fa;
    --text-secondary: #adb5bd;
    --text-muted: #6c757d;
    --accent-color: #4dabf7;
    --accent-hover: #74c0fc;
    --border-color: #495057;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.3);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.4);
}

/* ===================================
   Base Styles
   =================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: var(--font-sans);
    font-weight: 400;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    transition: background-color var(--transition-base), color var(--transition-base);
}

/* ===================================
   Floating Buttons
   =================================== */
.dark-mode-toggle,
.print-button,
.pdf-download {
    position: fixed;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background-color: var(--accent-color);
    color: white;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-base);
    z-index: 1000;
    text-decoration: none;
}

.dark-mode-toggle:hover,
.print-button:hover,
.pdf-download:hover {
    background-color: var(--accent-hover);
    transform: scale(1.1);
}

.dark-mode-toggle {
    top: 20px;
    right: 20px;
}

.print-button {
    top: 80px;
    right: 20px;
}

.pdf-download {
    top: 140px;
    right: 20px;
}

/* ===================================
   Container & Layout
   =================================== */
.container {
    max-width: 900px;
    margin: 0 auto;
    padding: var(--spacing-xl) var(--spacing-md);
}

/* ===================================
   Header Section
   =================================== */
.cv-header {
    text-align: center;
    padding: var(--spacing-xl) 0;
    margin-bottom: var(--spacing-xl);
    border-bottom: 2px solid var(--border-color);
}

.name {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
    font-family: var(--font-serif);
}

.title {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    font-weight: 300;
}

.title-affiliation {
    font-size: 1rem;
    color: var(--text-muted);
    font-weight: 300;
}

.contact-info {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-lg);
}

.contact-item {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-xs) var(--spacing-md);
    background-color: var(--bg-secondary);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    text-decoration: none;
    transition: all var(--transition-fast);
    font-size: 0.95rem;
    width: 100%;
    max-width: 300px;
}

.contact-item:hover {
    background-color: var(--accent-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.contact-item i {
    font-size: 1.1rem;
}

.contact-item-lab {
    background: linear-gradient(135deg, #059669, #0d9488);
    color: white !important;
    border: none;
    font-weight: 500;
}

.contact-item-lab:hover {
    background: linear-gradient(135deg, #047857, #0f766e);
    color: white !important;
}

.contact-item-lab i {
    color: white;
}

.lab-name-full {
    font-size: 0.75rem;
    opacity: 0.85;
    display: block;
    line-height: 1.2;
}

[data-theme="dark"] .contact-item-lab {
    background: linear-gradient(135deg, #065f46, #134e4a);
}

[data-theme="dark"] .contact-item-lab:hover {
    background: linear-gradient(135deg, #059669, #0d9488);
}

/* ===================================
   CV Sections
   =================================== */
.cv-section {
    margin-bottom: var(--spacing-xl);
    animation: fadeIn 0.6s ease-in;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.section-title {
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--accent-color);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-family: var(--font-serif);
}

.section-title i {
    color: var(--accent-color);
    font-size: 1.5rem;
}

.section-content {
    padding-left: var(--spacing-md);
}

/* ===================================
   Biography Section
   =================================== */
.biography .section-content p {
    font-size: 1.05rem;
    line-height: 1.8;
    color: var(--text-secondary);
    text-align: justify;
}

/* ===================================
   Timeline Items (Employment & Education)
   =================================== */
.timeline {
    position: relative;
    padding-left: var(--spacing-lg);
}

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

.timeline-item {
    position: relative;
    padding-bottom: var(--spacing-lg);
    padding-left: var(--spacing-lg);
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -6px;
    top: 6px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: var(--accent-color);
    border: 2px solid var(--bg-primary);
    box-shadow: 0 0 0 3px var(--accent-color);
    transition: all var(--transition-base);
}

.timeline-item:hover::before {
    transform: scale(1.3);
}

.timeline-period {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--accent-color);
    margin-bottom: var(--spacing-xs);
    display: inline-block;
    background-color: var(--bg-secondary);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
}

.timeline-position {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.timeline-organization,
.timeline-degree {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
}

.timeline-thesis {
    font-size: 0.95rem;
    color: var(--text-muted);
    font-style: italic;
    margin-top: 0.5rem;
}

.timeline-advisor {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-top: 0.25rem;
}

.timeline-advisor strong {
    color: var(--text-primary);
}

/* ===================================
   Skills Section
   =================================== */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.skill-item {
    background-color: var(--bg-secondary);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--accent-color);
    transition: all var(--transition-base);
}

.skill-item:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-md);
}

.skill-category {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.skill-list {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ===================================
   Projects Section
   =================================== */
.project-item {
    background-color: var(--bg-secondary);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--accent-color);
    transition: all var(--transition-base);
}

.project-item:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-sm);
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.project-period {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--accent-color);
    background-color: var(--bg-accent);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
}

.project-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
    line-height: 1.4;
}

.project-role {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
}

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

/* ===================================
   Publications Section
   =================================== */
.publication-category {
    margin-bottom: var(--spacing-md);
}

.publication-category.collapsed {
    margin-bottom: var(--spacing-md);
}

.publication-category:last-child {
    margin-bottom: 0;
}

/* Collapsible Header */
.publication-subtitle {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    border-left: 3px solid var(--accent-color);
    background-color: var(--bg-secondary);
    border-radius: var(--radius-md);
    cursor: pointer;
    user-select: none;
    transition: all var(--transition-base);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.publication-subtitle:hover {
    background-color: var(--bg-accent);
}

.collapse-icon {
    font-size: 1rem;
    transition: transform var(--transition-base);
    color: var(--accent-color);
}

.collapsible.collapsed .collapse-icon {
    transform: rotate(-90deg);
}

.pub-count {
    margin-left: auto;
    font-size: 0.9rem;
    color: var(--text-muted);
    background-color: var(--bg-accent);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
    font-weight: 500;
}

/* Collapsible Content */
.collapsible-content {
    max-height: 10000px;
    overflow: hidden;
    transition: max-height 0.4s ease-in-out, opacity 0.3s ease;
    opacity: 1;
}

.collapsible.collapsed .collapsible-content {
    max-height: 0;
    opacity: 0;
}

.publication-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    padding-top: var(--spacing-sm);
}

/* Publication Item with Number */
.publication-item {
    background-color: var(--bg-secondary);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    border-left: 3px solid var(--border-color);
    display: grid;
    grid-template-columns: 40px 1fr;
    gap: var(--spacing-md);
}

.publication-item:hover {
    border-left-color: var(--accent-color);
    box-shadow: var(--shadow-md);
    transform: translateX(3px);
}

/* JCR Q1 배지 강조 */
.jcr-q1-badge {
    font-weight: 700;
    color: #059669;
    background-color: #d1fae5;
    padding: 2px 8px;
    border-radius: 4px;
    border: 1px solid #6ee7b7;
}

[data-theme="dark"] .jcr-q1-badge {
    color: #6ee7b7;
    background-color: rgba(5, 150, 105, 0.2);
    border: 1px solid #059669;
}

/* JCR Ranking (퍼센테이지) 강조 */
.jcr-ranking-badge {
    font-weight: 600;
    color: #dc2626;
    background-color: #fee2e2;
    padding: 2px 8px;
    border-radius: 4px;
    border: 1px solid #fca5a5;
}

[data-theme="dark"] .jcr-ranking-badge {
    color: #fca5a5;
    background-color: rgba(220, 38, 38, 0.2);
    border: 1px solid #dc2626;
}

.publication-number {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--accent-color);
    text-align: center;
    padding-top: 0.25rem;
}

.publication-content {
    flex: 1;
}

.publication-title {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
    line-height: 1.4;
}

.publication-authors {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
}

.publication-venue {
    font-size: 0.9rem;
    color: var(--text-muted);
    font-style: italic;
    margin-bottom: 0.25rem;
}

.publication-meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: var(--spacing-xs);
}

.publication-year,
.publication-doi {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
}

.publication-doi a {
    color: var(--accent-color);
    text-decoration: none;
}

.publication-doi a:hover {
    text-decoration: underline;
}

/* Publication Metrics (IF, JCR) */
.publication-metrics {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
    font-style: italic;
}

/* ===================================
   Miscellaneous Section
   =================================== */
.subsection-title {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: var(--spacing-lg) 0 var(--spacing-md);
    padding-left: var(--spacing-sm);
    border-left: 3px solid var(--accent-color);
}

.subsection-title:first-child {
    margin-top: 0;
}

.awards-list,
.activities-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.award-item,
.activity-item {
    display: flex;
    gap: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--bg-secondary);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
}

.award-item:hover,
.activity-item:hover {
    background-color: var(--bg-accent);
    transform: translateX(3px);
}

.award-year,
.activity-year {
    font-weight: 600;
    color: var(--accent-color);
    min-width: 60px;
    flex-shrink: 0;
}

.award-content,
.activity-content {
    flex: 1;
}

.award-title,
.activity-title {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.award-org {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* ===================================
   References Section
   =================================== */
.references-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
}

.reference-item {
    background-color: var(--bg-secondary);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--accent-color);
    transition: all var(--transition-base);
}

.reference-item:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.reference-name {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.reference-position {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
}

.reference-org {
    font-size: 0.95rem;
    color: var(--text-muted);
    margin-bottom: var(--spacing-xs);
}

.reference-email {
    font-size: 0.9rem;
    color: var(--accent-color);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
}

.reference-email:hover {
    text-decoration: underline;
}

/* ===================================
   Footer
   =================================== */
.cv-footer {
    text-align: center;
    padding: var(--spacing-xl) 0 var(--spacing-md);
    margin-top: var(--spacing-xl);
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.9rem;
}

.cv-footer p {
    margin-bottom: 0.5rem;
}

.cv-footer a {
    color: var(--accent-color);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.cv-footer a:hover {
    color: var(--accent-hover);
    text-decoration: underline;
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 768px) {
    html {
        font-size: 14px;
    }

    .container {
        padding: var(--spacing-md) var(--spacing-sm);
    }

    .name {
        font-size: 2rem;
    }

    .contact-info {
        flex-direction: column;
        align-items: center;
    }

    .contact-item {
        width: 100%;
        max-width: 300px;
        justify-content: center;
    }

    .dark-mode-toggle,
    .print-button,
    .pdf-download {
        width: 40px;
        height: 40px;
        font-size: 1rem;
    }

    .print-button {
        top: 70px;
    }

    .pdf-download {
        top: 120px;
    }

    .timeline {
        padding-left: var(--spacing-md);
    }

    .timeline-item {
        padding-left: var(--spacing-md);
    }

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

    .project-header {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .section-content {
        padding-left: 0;
    }

    .biography .section-content p {
        text-align: left;
    }
}

/* ===================================
   Print Styles
   =================================== */
@media print {
    @page {
        margin: 2cm;
        size: A4;
    }

    body {
        font-size: 11pt;
        line-height: 1.4;
        color: #000;
        background: white;
    }

    .container {
        max-width: 100%;
        padding: 0;
    }

    .dark-mode-toggle,
    .print-button,
    .pdf-download {
        display: none !important;
    }

    .cv-section {
        page-break-inside: avoid;
        margin-bottom: 1.5rem;
    }

    .section-title {
        page-break-after: avoid;
    }

    .timeline-item,
    .project-item,
    .skill-item {
        page-break-inside: avoid;
    }

    a {
        color: #000;
        text-decoration: none;
    }

    a[href^="http"]:after {
        content: " (" attr(href) ")";
        font-size: 0.8em;
        color: #666;
    }

    .contact-item {
        background-color: transparent;
        border: 1px solid #ddd;
    }

    .cv-header {
        border-bottom: 2px solid #000;
    }

    .section-title {
        border-bottom: 1px solid #000;
    }

    .timeline::before {
        background: #333;
    }

    .timeline-item::before {
        border-color: white;
        box-shadow: 0 0 0 2px #333;
    }
}

/* ===================================
   Loading Animation
   =================================== */
.loading {
    opacity: 0.5;
    pointer-events: none;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.loading * {
    animation: pulse 1.5s ease-in-out infinite;
}