/* ========================================
PROFESSIONAL ACADEMIC PORTFOLIO
Clean, readable design for researchers
======================================== */

:root {
    --primary: #221a2f;
    --secondary: #5c5570;
    --accent: #7c6acb;
    --accent-light: #9a8ae0;
    --border: #ddd7ee;
    --bg-main: #ffffff;
    --bg-alt: #f8f6fd;
    --text-primary: #221a2f;
    --text-secondary: #5c5570;
    --text-muted: #7b7490;

    --font-serif: 'Crimson Pro', 'Georgia', serif;
    --font-sans: 'Source Sans 3', -apple-system, BlinkMacSystemFont, sans-serif;

    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 3rem;
    --spacing-xl: 4rem;

    --max-width: 1100px;
    --max-width-narrow: 800px;
}

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

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

body {
    font-family: var(--font-sans);
    font-weight: 400;
    line-height: 1.7;
    color: var(--text-primary);
    background-color: var(--bg-main);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-serif);
    font-weight: 600;
    line-height: 1.3;
    color: var(--primary);
    margin-bottom: var(--spacing-sm);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
    margin-bottom: var(--spacing-sm);
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: color 0.2s ease;
}

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

ul {
    list-style: none;
}

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

/* Navigation */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    padding: var(--spacing-sm) 0;
}

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

.nav-spacer {
    width: 160px;
    flex-shrink: 0;
}

.nav-menu {
    display: flex;
    gap: var(--spacing-md);
}

.nav-menu a {
    font-size: 0.95rem;
    font-weight: 400;
    color: var(--text-secondary);
    padding: 0.5rem 0;
    border-bottom: 2px solid transparent;
    transition: all 0.2s ease;
}

.nav-menu a:hover {
    color: var(--accent);
    border-bottom-color: var(--accent);
}

/* Header */
.header {
    padding: calc(var(--spacing-xl) + 60px) 0 var(--spacing-xl) 0;
    background: linear-gradient(to bottom, var(--bg-alt) 0%, var(--bg-main) 100%);
    border-bottom: 1px solid var(--border);
}

.header-content {
    max-width: var(--max-width-narrow);
    margin: 0 auto;
}

.header-main {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.profile-image-container {
    flex-shrink: 0;
}

.profile-image {
    width: 140px;
    height: 140px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid var(--accent);
    box-shadow: 0 4px 12px rgba(124, 106, 203, 0.15);
}

.header-text {
    flex: 1;
}

.header-title {
    font-size: 2.5rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    color: var(--primary);
    line-height: 1.2;
}

.header-subtitle {
    font-size: 1.35rem;
    color: var(--text-secondary);
    font-weight: 300;
    margin-bottom: var(--spacing-xs);
}

.header-affiliation {
    font-size: 1rem;
    color: var(--text-muted);
    line-height: 1.6;
    margin-bottom: 0;
}

.header-links {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

.link-button {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 1.2rem;
    background: var(--bg-main);
    border: 1px solid var(--border);
    border-radius: 4px;
    font-size: 0.9rem;
    color: var(--text-primary);
    transition: all 0.2s ease;
}

.link-button:hover {
    border-color: var(--accent);
    color: var(--accent);
    transform: translateY(-2px);
    box-shadow: 0 2px 8px rgba(124, 106, 203, 0.12);
}

.link-button.cv {
    background: var(--accent);
    color: white;
    border-color: var(--accent);
}

.link-button.cv:hover {
    background: var(--accent-light);
    border-color: var(--accent-light);
    color: white;
}

.link-button svg {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
}

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

.section-alt {
    background-color: var(--bg-alt);
}

.section-title {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--accent);
    display: inline-block;
}

.subsection-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin: var(--spacing-lg) 0 var(--spacing-md) 0;
    color: var(--primary);
}

/* About */
.about-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-md);
}

.about-main {
    max-width: 700px;
}

.lead {
    font-size: 1.15rem;
    line-height: 1.8;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

.interests-box {
    background: var(--bg-main);
    border: 1px solid var(--border);
    border-left: 3px solid var(--accent);
    padding: var(--spacing-md);
    border-radius: 4px;
}

.interests-box h3 {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-sm);
    color: var(--primary);
}

.interests-list li {
    padding: 0.4rem 0 0.4rem 1.2rem;
    position: relative;
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.interests-list li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: bold;
}

/* Metrics */
.metrics-container {
    max-width: var(--max-width-narrow);
    margin: var(--spacing-md) auto 0;
}

.metrics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.metric-card {
    background: var(--bg-main);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    transition: all 0.3s ease;
}

.metric-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 4px 12px rgba(124, 106, 203, 0.12);
    border-color: var(--accent);
}

.metric-content {
    flex: 1;
}

.metric-value {
    font-size: 2rem;
    font-weight: 600;
    color: var(--primary);
    font-family: var(--font-serif);
    line-height: 1;
    margin-bottom: 0.25rem;
}

.metric-label {
    font-size: 0.9rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.scholar-link-container {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border);
}

.scholar-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: var(--bg-main);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--accent);
    font-size: 0.95rem;
    font-weight: 500;
    transition: all 0.2s ease;
}

.scholar-link:hover {
    background: var(--accent);
    color: white;
    border-color: var(--accent);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(124, 106, 203, 0.18);
}

/* Timeline */
.timeline {
    max-width: var(--max-width-narrow);
    margin: var(--spacing-md) auto 0;
}

.timeline-item {
    display: grid;
    grid-template-columns: 140px 1fr;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--border);
}

.timeline-item:last-child {
    border-bottom: none;
}

.timeline-date {
    font-family: var(--font-serif);
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--accent);
    padding-top: 0.2rem;
}

.timeline-content h3 {
    font-size: 1.25rem;
    margin-bottom: 0.3rem;
    color: var(--primary);
}

.institution {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.project-title {
    font-style: italic;
    color: var(--text-primary);
    margin: 0.5rem 0;
    line-height: 1.6;
}

.advisor {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-top: 0.5rem;
}

/* Education */
.education-grid {
    display: grid;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-md);
}

.education-card {
    background: var(--bg-main);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: var(--spacing-md);
}

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

.degree-header h3 {
    font-size: 1.5rem;
    margin: 0;
}

.degree-header .date {
    font-size: 0.9rem;
    color: var(--text-muted);
    font-family: var(--font-serif);
}

.program {
    font-size: 1.1rem;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.program-detail,
.gpa {
    font-size: 0.95rem;
    color: var(--text-secondary);
}

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

.institution-block {
    margin-bottom: var(--spacing-md);
}

.institution-block:last-child {
    margin-bottom: 0;
}

.institution-block h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--accent);
    margin-bottom: 0.5rem;
}

.course-list {
    margin-top: 0.5rem;
}

.course-list li {
    padding: 0.25rem 0 0.25rem 1.2rem;
    position: relative;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.course-list li::before {
    content: '–';
    position: absolute;
    left: 0;
    color: var(--text-muted);
}

/* Publications */
.publications-section {
    margin-bottom: var(--spacing-lg);
}

.publication-item {
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid var(--border);
}

.publication-item:last-child {
    border-bottom: none;
}

.pub-title {
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 0.3rem;
    line-height: 1.5;
}

.pub-venue {
    font-size: 0.9rem;
    color: var(--text-muted);
    font-style: italic;
}

.doi {
    font-size: 0.85rem;
    color: var(--accent);
    font-family: 'Courier New', monospace;
    word-break: break-word;
}

.project-list {
    display: grid;
    gap: var(--spacing-md);
}

.project-item {
    padding: var(--spacing-sm);
    background: var(--bg-main);
    border-left: 3px solid var(--accent);
    border-radius: 4px;
}

.project-item h4 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: var(--primary);
}

.project-item p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 0.3rem;
}

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

.skill-category {
    background: var(--bg-main);
    padding: var(--spacing-sm);
    border-radius: 4px;
    border: 1px solid var(--border);
}

.skill-category h4 {
    font-size: 1rem;
    margin-bottom: 0.5rem;
    color: var(--primary);
}

.skill-category p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin: 0;
}

/* Activities */
.activities-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-md);
}

.activity-item h3 {
    font-size: 1.3rem;
    margin-bottom: var(--spacing-md);
    color: var(--primary);
    border-bottom: 1px solid var(--border);
    padding-bottom: var(--spacing-xs);
}

.activity-entry {
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid #ece7f7;
}

.activity-entry:last-child {
    border-bottom: none;
}

.activity-role {
    font-size: 1rem;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 0.2rem;
}

.activity-institution {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 0.2rem;
}

.activity-date {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
    font-style: italic;
}

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

.memberships {
    margin-top: var(--spacing-lg);
    padding-top: var(--spacing-lg);
    border-top: 2px solid var(--border);
}

.memberships h3 {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-sm);
}

.memberships p {
    font-size: 0.95rem;
    color: var(--text-secondary);
}

/* Footer */
.footer {
    background: var(--bg-alt);
    border-top: 1px solid var(--border);
    padding: var(--spacing-md) 0;
    text-align: center;
    margin-top: var(--spacing-xl);
}

.footer p {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin: 0;
}

/* Responsive */
@media (max-width: 900px) {
    .about-grid,
    .activities-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    :root {
        font-size: 15px;
    }

    .nav-spacer {
        display: none;
    }

    .nav-container {
        justify-content: center;
    }

    .nav-menu {
        display: none;
    }

    .header-main {
        flex-direction: column;
        text-align: center;
    }

    .profile-image {
        width: 120px;
        height: 120px;
    }

    .header-title {
        font-size: 2rem;
    }

    .header-subtitle {
        font-size: 1.15rem;
    }

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

    .timeline-item {
        grid-template-columns: 1fr;
        gap: var(--spacing-xs);
    }

    .timeline-date {
        font-size: 0.85rem;
    }

    .degree-header {
        flex-direction: column;
        align-items: flex-start;
    }
}

@media (max-width: 480px) {
    .header-links {
        flex-direction: column;
    }

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

@media print {
    .nav,
    .footer {
        display: none;
    }

    .section {
        page-break-inside: avoid;
    }

    a {
        color: var(--text-primary);
        text-decoration: underline;
    }
}