/* Design System - Professional Light Blue Theme */
:root {
    /* Light Mode Palette (Default) */
    --md-sys-color-primary: #0061A4;
    --md-sys-color-on-primary: #FFFFFF;
    --md-sys-color-primary-container: #D1E4FF;
    --md-sys-color-on-primary-container: #001D36;
    --md-sys-color-secondary: #535F70;
    --md-sys-color-on-secondary: #FFFFFF;
    --md-sys-color-surface: #F8F9FF;
    --md-sys-color-on-surface: #191C1E;
    --md-sys-color-surface-variant: #DFE2EB;
    --md-sys-color-on-surface-variant: #43474E;
    --md-sys-color-outline: #73777F;
    
    /* Typography */
    --font-family-title: 'Google Sans Flex', sans-serif;
    --font-family-body: 'Roboto Flex', sans-serif;
    
    /* Spacing & Borders */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --border-radius-sm: 8px;
    --border-radius-md: 16px;
    --border-radius-lg: 28px;
    
    /* Transitions */
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-standard: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

@media (prefers-color-scheme: dark) {
    :root {
        --md-sys-color-primary: #A0C9FF;
        --md-sys-color-on-primary: #003258;
        --md-sys-color-primary-container: #00497D;
        --md-sys-color-on-primary-container: #D1E4FF;
        --md-sys-color-secondary: #BBC7DB;
        --md-sys-color-on-secondary: #253140;
        --md-sys-color-surface: #191C1E;
        --md-sys-color-on-surface: #E1E2E5;
        --md-sys-color-surface-variant: #43474E;
        --md-sys-color-on-surface-variant: #C3C7CF;
        --md-sys-color-outline: #8D9199;
    }
}

/* Reset & Global Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-family-body);
    background-color: var(--md-sys-color-surface);
    color: var(--md-sys-color-on-surface);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    transition: background-color var(--transition-standard), color var(--transition-standard);
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-family-title);
    font-weight: 500;
    color: var(--md-sys-color-on-surface);
    letter-spacing: -0.02em;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* Header & Navigation */
.main-header {
    height: 80px;
    display: flex;
    align-items: center;
    background-color: var(--md-sys-color-surface);
    border-bottom: 1px solid var(--md-sys-color-surface-variant);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo-text {
    font-family: var(--font-family-title);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--md-sys-color-primary);
}

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

.nav-link {
    font-family: var(--font-family-title);
    font-weight: 500;
    font-size: 1rem;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius-md);
}

.nav-link:hover {
    background-color: var(--md-sys-color-primary-container);
    color: var(--md-sys-color-on-primary-container);
}

/* Footer */
.main-footer {
    padding: var(--spacing-xl) 0;
    background-color: var(--md-sys-color-surface);
    border-top: 1px solid var(--md-sys-color-surface-variant);
    margin-top: auto;
}

.footer-container {
    text-align: center;
    color: var(--md-sys-color-on-surface-variant);
    font-size: 0.875rem;
}

/* Page Components */
main {
    padding: var(--spacing-xl) 0;
    min-height: calc(100vh - 80px - 100px); /* Adjust based on header/footer height */
}

.page-title {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-lg);
}

/* Micro-animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.fade-in {
    opacity: 0;
    animation: fadeIn 0.6s var(--transition-standard) forwards;
}

/* Premium Navigation Elements */
.nav-link.active {
    background-color: var(--md-sys-color-primary-container);
    color: var(--md-sys-color-on-primary-container);
    font-weight: 700;
}

/* Premium Hero Elements */
.hero-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: var(--spacing-xl) 0;
    margin-top: calc(8vh);
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.hero-title {
    font-size: 3rem;
    line-height: 1.2;
    margin-bottom: var(--spacing-lg);
    background: linear-gradient(135deg, var(--md-sys-color-primary), var(--md-sys-color-outline));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--md-sys-color-on-surface-variant);
    margin-bottom: var(--spacing-xl);
    max-width: 650px;
}

.hero-actions {
    display: flex;
    gap: var(--spacing-md);
}

/* Premium Button Elements */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-family-title);
    font-weight: 600;
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: var(--border-radius-lg);
    font-size: 1rem;
    cursor: pointer;
    border: none;
    transition: transform var(--transition-fast), background-color var(--transition-fast), box-shadow var(--transition-fast);
}

.btn:hover {
    transform: translateY(-2px);
}

.btn:active {
    transform: translateY(0);
}

.btn-primary {
    background-color: var(--md-sys-color-primary);
    color: var(--md-sys-color-on-primary);
    box-shadow: 0 4px 12px rgba(0, 97, 164, 0.15);
}

.btn-primary:hover {
    background-color: #005088;
    box-shadow: 0 6px 16px rgba(0, 97, 164, 0.25);
}

.btn-secondary {
    background-color: var(--md-sys-color-primary-container);
    color: var(--md-sys-color-on-primary-container);
}

.btn-secondary:hover {
    background-color: #c0d7fa;
}

.btn-sm {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 0.875rem;
    border-radius: var(--border-radius-md);
}

/* Premium Layout Container & Card Adjustments */
.content-card {
    background-color: var(--md-sys-color-surface-variant);
    padding: var(--spacing-xl);
    border-radius: var(--border-radius-lg);
    margin-bottom: var(--spacing-xl);
    border: 1px solid rgba(0, 0, 0, 0.05);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.02);
    transition: transform var(--transition-standard), box-shadow var(--transition-standard);
}

.section-title {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-md);
    margin-top: var(--spacing-xl);
    border-bottom: 2px solid var(--md-sys-color-primary-container);
    padding-bottom: var(--spacing-sm);
}

.section-title:first-of-type {
    margin-top: 0;
}

.about-text {
    margin-bottom: var(--spacing-md);
    color: var(--md-sys-color-on-surface-variant);
    font-size: 1.05rem;
}

.skills-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

.skill-category {
    background-color: var(--md-sys-color-surface);
    padding: var(--spacing-md);
    border-radius: var(--border-radius-md);
    border-left: 4px solid var(--md-sys-color-primary);
}

/* Chronological Timeline Elements */
.resume-container {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
    max-width: 960px;
    margin: 0 auto;
}

.timeline {
    position: relative;
    padding-left: var(--spacing-xl);
    margin-top: var(--spacing-lg);
}

.timeline::before {
    content: '';
    position: absolute;
    left: 8px;
    top: 0;
    bottom: 0;
    width: 2px;
    background-color: var(--md-sys-color-outline);
    opacity: 0.3;
}

.timeline-item {
    position: relative;
    margin-bottom: var(--spacing-xl);
}

.timeline-marker {
    position: absolute;
    left: -32px;
    top: 8px;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background-color: var(--md-sys-color-primary);
    border: 4px solid var(--md-sys-color-surface);
    box-shadow: 0 0 0 2px var(--md-sys-color-primary-container);
    transition: background-color var(--transition-fast);
}

.timeline-item:hover .timeline-marker {
    background-color: var(--md-sys-color-secondary);
}

.timeline-content {
    margin-bottom: 0;
}

.timeline-period {
    display: inline-block;
    font-family: var(--font-family-title);
    font-weight: 700;
    font-size: 0.875rem;
    color: var(--md-sys-color-primary);
    background-color: var(--md-sys-color-primary-container);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--border-radius-sm);
    margin-bottom: var(--spacing-sm);
}

.timeline-role, .timeline-degree {
    font-size: 1.35rem;
    margin-bottom: var(--spacing-xs);
}

.timeline-company, .timeline-institution {
    font-size: 1rem;
    color: var(--md-sys-color-on-surface-variant);
    margin-bottom: var(--spacing-md);
}

.timeline-location {
    font-weight: normal;
    font-style: italic;
}

.timeline-responsibilities {
    list-style-type: none;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.timeline-responsibilities li {
    position: relative;
    padding-left: var(--spacing-md);
    color: var(--md-sys-color-on-surface-variant);
}

.timeline-responsibilities li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--md-sys-color-primary);
    font-weight: bold;
}

.timeline-details {
    color: var(--md-sys-color-on-surface-variant);
}

/* Premium Project CSS Grid Elements */
.projects-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
    margin-top: var(--spacing-lg);
    max-width: 860px;
    margin-left: auto;
    margin-right: auto;
}

.project-card {
    display: flex;
    flex-direction: column;
    height: 100%;
    transition: transform var(--transition-standard), box-shadow var(--transition-standard);
}

.project-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
}

.project-title {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--md-sys-color-primary);
}

.project-description {
    color: var(--md-sys-color-on-surface-variant);
    margin-bottom: var(--spacing-lg);
    flex-grow: 1;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-xl);
}

.tech-pill {
    font-family: var(--font-family-body);
    font-size: 0.75rem;
    font-weight: 600;
    background-color: var(--md-sys-color-surface);
    color: var(--md-sys-color-secondary);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--border-radius-sm);
    border: 1px solid var(--md-sys-color-outline);
    opacity: 0.8;
}

.project-actions {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: auto;
}

/* Premium Direct Contact Coordinates */
.contact-card {
    max-width: 650px;
    margin: var(--spacing-xl) auto;
}

.contact-subtitle {
    font-size: 1.1rem;
    color: var(--md-sys-color-on-surface-variant);
    margin-bottom: var(--spacing-xl);
}

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

.contact-method {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background-color: var(--md-sys-color-surface);
    border-radius: var(--border-radius-md);
    border: 1px solid rgba(0, 0, 0, 0.03);
}

.contact-label {
    font-family: var(--font-family-title);
    font-weight: 700;
    color: var(--md-sys-color-primary);
    min-width: 90px;
}

.contact-link {
    color: var(--md-sys-color-on-surface);
    font-weight: 500;
    transition: color var(--transition-fast);
}

.contact-link:hover {
    color: var(--md-sys-color-primary);
    text-decoration: underline;
}

.contact-value {
    color: var(--md-sys-color-on-surface-variant);
}

/* Responsive timeline layout uses single-column on all viewports */

/* Native Scroll Behavior */
html {
    scroll-behavior: smooth;
}

/* Dashboard Highlight Sections */
.highlight-section {
    margin-top: calc(8vh);
    margin-bottom: calc(8vh);
}

.highlight-actions {
    display: flex;
    justify-content: flex-start;
    margin-top: var(--spacing-md);
}

.contact-highlight-link {
    color: var(--md-sys-color-primary);
    font-weight: 700;
    text-decoration: none;
    transition: color var(--transition-fast);
}

.contact-highlight-link:hover {
    text-decoration: underline;
}

/* Global Footer Email coordinates */
.footer-email {
    font-size: 0.875rem;
    color: var(--md-sys-color-on-surface-variant);
    margin-top: var(--spacing-xs);
}

.footer-email-link {
    color: var(--md-sys-color-primary);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.footer-email-link:hover {
    text-decoration: underline;
}

/* Premium Responsive 16:9 Video Container */
.video-container {
    position: relative;
    padding-bottom: 56.25%; /* 16:9 Aspect Ratio */
    height: 0;
    overflow: hidden;
    max-width: 100%;
    border-radius: var(--border-radius-md);
    background-color: #000;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    margin-top: var(--spacing-md);
}

.video-container .video-player,
.video-container .video-iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: 0;
    border-radius: var(--border-radius-md);
    object-fit: cover;
}

/* Dynamic Project Badges */
.badge {
    display: inline-block;
    font-family: var(--font-family-title);
    font-weight: 700;
    font-size: 0.7rem;
    padding: 2px var(--spacing-sm);
    border-radius: var(--border-radius-sm);
    margin-left: var(--spacing-sm);
    vertical-align: middle;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.badge-academic {
    background-color: #E8F5E9;
    color: #2E7D32;
    border: 1px solid #C8E6C9;
}

.badge-professional {
    background-color: #E3F2FD;
    color: #1565C0;
    border: 1px solid #BBDEFB;
}

@media (prefers-color-scheme: dark) {
    .badge-academic {
        background-color: #1B5E20;
        color: #C8E6C9;
        border: 1px solid #2E7D32;
    }
    
    .badge-professional {
        background-color: #0D47A1;
        color: #BBDEFB;
        border: 1px solid #1565C0;
    }
}

.project-association {
    font-family: var(--font-family-body);
    font-size: 0.875rem;
    color: var(--md-sys-color-outline);
    font-weight: normal;
    margin-left: var(--spacing-sm);
}

/* Timeline Experience Skills */
.timeline-skills {
    margin-top: var(--spacing-md);
    font-size: 0.875rem;
    color: var(--md-sys-color-on-surface-variant);
}

.skill-tag {
    display: inline-block;
    background-color: var(--md-sys-color-surface);
    color: var(--md-sys-color-primary);
    border: 1px solid var(--md-sys-color-outline);
    padding: 2px 6px;
    font-size: 0.75rem;
    border-radius: var(--border-radius-sm);
    margin: 2px;
    font-weight: 600;
}

/* Patent Details Styling */
.patent-details {
    margin-top: var(--spacing-md);
    border-top: 1px solid var(--md-sys-color-surface-variant);
    padding-top: var(--spacing-md);
}

.patent-subtitle {
    font-family: var(--font-family-title);
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--md-sys-color-on-surface);
    margin-bottom: var(--spacing-xs);
    margin-top: var(--spacing-md);
}

.patent-text {
    font-size: 0.875rem;
    color: var(--md-sys-color-on-surface-variant);
    line-height: 1.6;
    margin-bottom: var(--spacing-sm);
}

/* Project Media & Thumbnail styles */
.project-media-container {
    position: relative;
    width: 100%;
    padding-bottom: 56.25%; /* 16:9 Aspect Ratio */
    height: 0;
    overflow: hidden;
    border-radius: var(--border-radius-md);
    background-color: #000;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    margin-bottom: var(--spacing-lg);
    cursor: pointer;
    transition: transform var(--transition-standard), box-shadow var(--transition-standard);
}

.project-media-container:hover {
    transform: scale(1.02);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

.project-media-thumbnail {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: filter var(--transition-standard);
}

.project-media-container:hover .project-media-thumbnail {
    filter: brightness(0.8);
}

.project-media-placeholder {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--md-sys-color-primary-container), var(--md-sys-color-surface-variant));
    color: var(--md-sys-color-primary);
}

.project-media-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity var(--transition-standard);
    background-color: rgba(0, 0, 0, 0.3);
}

.project-media-container:hover .project-media-overlay {
    opacity: 1;
}

.play-button-icon,
.zoom-button-icon {
    color: #fff;
    background-color: var(--md-sys-color-primary);
    border-radius: 50%;
    padding: var(--spacing-md);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    transition: transform var(--transition-fast);
}

.project-media-container:hover .play-button-icon,
.project-media-container:hover .zoom-button-icon {
    transform: scale(1.1);
}

/* Modal styles */
.media-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-standard);
}

.media-modal.active {
    opacity: 1;
    pointer-events: auto;
}

.media-modal-close {
    position: absolute;
    top: 24px;
    right: 24px;
    background: none;
    border: none;
    color: #fff;
    font-size: 3rem;
    cursor: pointer;
    line-height: 1;
    z-index: 1010;
    transition: transform var(--transition-fast), color var(--transition-fast);
}

.media-modal-close:hover {
    transform: scale(1.1);
    color: var(--md-sys-color-primary);
}

.media-modal-content {
    width: 90%;
    max-width: 960px;
    display: flex;
    flex-direction: column;
    align-items: center;
    transform: scale(0.9);
    transition: transform var(--transition-standard);
}

.media-modal.active .media-modal-content {
    transform: scale(1);
}

.media-modal-body {
    position: relative;
    width: 100%;
    padding-bottom: 56.25%; /* 16:9 Aspect Ratio */
    height: 0;
    border-radius: var(--border-radius-md);
    overflow: hidden;
    background-color: #000;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
}

.media-modal-body iframe,
.media-modal-body video {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: 0;
}

.media-modal-body.image-view {
    padding-bottom: 0;
    height: auto;
    max-height: 80vh;
}

.media-modal-body.image-view img {
    position: relative;
    max-height: 80vh;
    width: auto;
    max-width: 100%;
    display: block;
    margin: 0 auto;
    border-radius: var(--border-radius-md);
}

.media-modal-title {
    margin-top: var(--spacing-lg);
    color: #fff;
    font-size: 1.5rem;
    text-align: center;
}

/* Prevent body scroll when modal active */
body.modal-open {
    overflow: hidden;
}