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

:root {
    /* Simple PDF-style color palette */
    --primary-color: #000000;
    --text-primary: #000000;
    --text-secondary: #333333;
    --accent-color: #0066cc;
    --background-primary: #ffffff;
    --border-color: #cccccc;
    
    /* Typography - Times-like serif font */
    --font-family: 'Times New Roman', Times, serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    
    /* Minimal spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    line-height: 1.5;
    color: var(--text-primary);
    background-color: var(--background-primary);
    font-size: var(--font-size-base);
    padding-top: 50px;
}

/* Top Navigation Header - Minimal Faculty Style */
.top-nav-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 50px;
    background-color: var(--background-primary);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
}

.nav-container {
    max-width: 900px;
    margin: 0 auto;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding: 0 var(--spacing-lg);
}

.main-navigation {
    height: 100%;
    display: flex;
    align-items: center;
}

.nav-list {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
    gap: 0;
}

.nav-list li {
    margin: 0;
}

.nav-link {
    display: block;
    padding: var(--spacing-md) var(--spacing-lg);
    text-decoration: none;
    color: var(--text-primary);
    font-size: var(--font-size-base);
    font-weight: normal;
    height: 50px;
    display: flex;
    align-items: center;
}

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

.nav-link.active {
    color: var(--accent-color);
    font-weight: bold;
}

/* Main Layout */
.main-container {
    max-width: 900px;
    margin: 0 auto;
    padding: var(--spacing-xl);
    background-color: var(--background-primary);
    min-height: calc(100vh - 50px);
}

/* Content Sections */
.content-section {
    display: none;
}

.content-section.active {
    display: block;
}

/* Home Header - Two Column Layout */
.home-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
}

.left-column {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.right-column {
    flex: 0 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
}

/* Profile Photo */
.profile-photo {
    width: 200px;
    object-fit: cover;
    border: 1px solid var(--border-color);
}

.personal-info h1.name {
    font-size: var(--font-size-2xl);
    font-weight: bold;
    margin-bottom: var(--spacing-xs);
    color: var(--primary-color);
}

.personal-info .title {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-xs);
    color: var(--text-secondary);
}

.personal-info .affiliation,
.personal-info .location {
    font-size: var(--font-size-base);
    margin-bottom: var(--spacing-xs);
    color: var(--text-secondary);
}

.contact-info p {
    margin-bottom: var(--spacing-xs);
    font-size: var(--font-size-sm);
}

.contact-info a {
    color: var(--accent-color);
    text-decoration: none;
}

.contact-info a:hover {
    text-decoration: underline;
}

/* Greeting Section */
.greeting-section {
    text-align: center;
}

.greeting-message {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: var(--font-size-lg);
    font-weight: bold;
}

.greeting-text {
    color: var(--text-primary);
}

.mcdonalds-logo {
    height: 24px;
    width: auto;
    transition: transform 0.3s ease;
}

.greeting-message:hover .mcdonalds-logo {
    transform: scale(1.1) rotate(5deg);
}

/* Section Blocks */
.section-block {
    margin-bottom: var(--spacing-xl);
}

.section-block h2 {
    font-size: var(--font-size-xl);
    font-weight: bold;
    margin-bottom: var(--spacing-lg);
    color: var(--primary-color);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: var(--spacing-sm);
}

.section-block p {
    margin-bottom: var(--spacing-md);
    text-align: justify;
}

/* Education Items */
.education-item {
    margin-bottom: var(--spacing-lg);
}

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

.education-header h3 {
    font-size: var(--font-size-lg);
    font-weight: bold;
    margin: 0;
    flex: 1;
}

.date {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    white-space: nowrap;
    margin-left: var(--spacing-md);
}

.institution {
    font-style: italic;
    margin-bottom: var (--spacing-xs);
    color: var (--text-secondary);
}

.details {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
}

/* Research Items */
.research-item {
    margin-bottom: var(--spacing-lg);
}

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

.research-header h3 {
    font-size: var(--font-size-base);
    font-weight: bold;
    margin: 0;
    flex: 1;
}

.supervisor {
    font-style: italic;
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
}

.details-list {
    margin-left: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.details-list li {
    margin-bottom: var(--spacing-xs);
    text-align: justify;
}

.details-list a {
    color: var(--accent-color);
    text-decoration: none;
}

.details-list a:hover {
    text-decoration: underline;
}

/* Publication Items */
.publication-item {
    margin-bottom: var(--spacing-lg);
}

.paper-title {
    font-weight: bold;
    margin-bottom: var(--spacing-xs);
    font-size: var(--font-size-base);
}

.paper-authors {
    margin-bottom: var(--spacing-xs);
    font-style: italic;
}

.paper-authors strong {
    font-weight: bold;
    font-style: normal;
}

.paper-venue {
    margin-bottom: var (--spacing-xs);
    font-style: italic;
    color: var (--text-secondary);
}

.paper-doi {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    font-family: monospace;
}

/* Project Items */
.project-item {
    margin-bottom: var(--spacing-lg);
}

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

.project-header h3 {
    font-size: var(--font-size-lg);
    font-weight: bold;
    margin: 0;
    flex: 1;
}

.project-tech {
    font-size: var(--font-size-sm);
    font-style: italic;
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
}

.project-description {
    margin-bottom: var(--spacing-sm);
    text-align: justify;
}

.project-link {
    font-size: var(--font-size-sm);
}

.project-link a {
    color: var(--accent-color);
    text-decoration: none;
}

.project-link a:hover {
    text-decoration: underline;
}

/* Experience Items */
.experience-item {
    margin-bottom: var (--spacing-lg);
}

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

.experience-header h3 {
    font-size: var(--font-size-lg);
    font-weight: bold;
    margin: 0;
    flex: 1;
}

/* Skills Section */
.skills-section {
    margin-bottom: var(--spacing-lg);
}

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

.skill-category h4 {
    font-size: var(--font-size-base);
    font-weight: bold;
    margin-bottom: var(--spacing-xs);
}

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

/* Award Items */
.award-item {
    margin-bottom: var(--spacing-md);
}

.award-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}

.award-header h3 {
    font-size: var(--font-size-base);
    font-weight: bold;
    margin: 0;
    flex: 1;
}

.award-level {
    font-size: var(--font-size-sm);
    color: var (--text-secondary);
    white-space: nowrap;
    margin-left: var(--spacing-md);
}

/* Activity Items */
.activity-item {
    margin-bottom: var(--spacing-md);
}

.activity-item h3 {
    font-size: var(--font-size-base);
    font-weight: bold;
    margin-bottom: var(--spacing-xs);
}

.activity-item p {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    margin: 0;
}

/* Links */
a {
    color: var(--accent-color);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 768px) {
    .main-container {
        padding: var(--spacing-md);
    }
    
    .home-header {
        flex-direction: column;
        gap: var(--spacing-lg);
    }
    
    .profile-photo {
        width: 100px;
        height: 125px;
        margin: 0 auto var(--spacing-md);
    }
    
    .education-header,
    .research-header,
    .project-header,
    .experience-header,
    .award-header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .date,
    .award-level {
        margin-left: 0;
        margin-top: var(--spacing-xs);
    }
}