/* ============================================
   Material Design 3 Academic Portfolio
   Color System & Design Tokens
   ============================================ */

:root {
    /* Primary Color - Indigo/Blue (Material 3 Dark Theme) */
    --md-sys-color-primary: #a5b4fc;
    --md-sys-color-on-primary: #1e1b4b;
    --md-sys-color-primary-container: #3730a3;
    --md-sys-color-on-primary-container: #e0e7ff;

    /* Secondary Color - Cyan/Teal */
    --md-sys-color-secondary: #67e8f9;
    --md-sys-color-on-secondary: #083344;
    --md-sys-color-secondary-container: #155e75;
    --md-sys-color-on-secondary-container: #cffafe;

    /* Tertiary Color - Violet accent */
    --md-sys-color-tertiary: #c4b5fd;
    --md-sys-color-on-tertiary: #2e1065;
    --md-sys-color-tertiary-container: #5b21b6;
    --md-sys-color-on-tertiary-container: #ede9fe;

    /* Error */
    --md-sys-color-error: #fca5a5;
    --md-sys-color-on-error: #450a0a;
    --md-sys-color-error-container: #991b1b;
    --md-sys-color-on-error-container: #fee2e2;

    /* Surface Colors - Navy/Black Dark Theme */
    --md-sys-color-background: #0a0f1a;
    --md-sys-color-on-background: #e2e8f0;
    --md-sys-color-surface: #0f172a;
    --md-sys-color-on-surface: #e2e8f0;
    --md-sys-color-surface-variant: #1e293b;
    --md-sys-color-on-surface-variant: #94a3b8;
    --md-sys-color-surface-container: #1e293b;
    --md-sys-color-surface-container-low: #0f172a;
    --md-sys-color-surface-container-high: #334155;
    --md-sys-color-surface-container-highest: #475569;

    /* Outline */
    --md-sys-color-outline: #64748b;
    --md-sys-color-outline-variant: #334155;

    /* Typography Scale */
    --md-sys-typescale-display-large: 600 3.5rem/1.1 'Roboto Flex', sans-serif;
    --md-sys-typescale-display-medium: 500 2.75rem/1.15 'Roboto Flex', sans-serif;
    --md-sys-typescale-headline-large: 500 2rem/1.25 'Roboto Flex', sans-serif;
    --md-sys-typescale-headline-medium: 500 1.75rem/1.3 'Roboto Flex', sans-serif;
    --md-sys-typescale-title-large: 500 1.375rem/1.35 'Roboto Flex', sans-serif;
    --md-sys-typescale-title-medium: 500 1rem/1.4 'Roboto Flex', sans-serif;
    --md-sys-typescale-body-large: 400 1rem/1.6 'Roboto Flex', sans-serif;
    --md-sys-typescale-body-medium: 400 0.875rem/1.5 'Roboto Flex', sans-serif;
    --md-sys-typescale-label-large: 500 0.875rem/1.4 'Roboto Flex', sans-serif;
    --md-sys-typescale-label-medium: 500 0.75rem/1.35 'Roboto Flex', sans-serif;
    --md-sys-typescale-body-small: 400 0.75rem/1.5 'Roboto Flex', sans-serif;

    /* Elevation - Dark theme shadows with subtle glow */
    --md-sys-elevation-1: 0 1px 3px rgba(0,0,0,0.4), 0 1px 2px rgba(0,0,0,0.3);
    --md-sys-elevation-2: 0 3px 6px rgba(0,0,0,0.4), 0 2px 4px rgba(0,0,0,0.3);
    --md-sys-elevation-3: 0 6px 12px rgba(0,0,0,0.4), 0 4px 8px rgba(0,0,0,0.3);

    /* Shape */
    --md-sys-shape-corner-none: 0;
    --md-sys-shape-corner-extra-small: 4px;
    --md-sys-shape-corner-small: 8px;
    --md-sys-shape-corner-medium: 12px;
    --md-sys-shape-corner-large: 16px;
    --md-sys-shape-corner-extra-large: 28px;

    /* Motion */
    --md-sys-motion-easing-standard: cubic-bezier(0.2, 0, 0, 1);
    --md-sys-motion-easing-emphasized: cubic-bezier(0.2, 0, 0, 1);
    --md-sys-motion-duration-short: 150ms;
    --md-sys-motion-duration-medium: 250ms;
    --md-sys-motion-duration-long: 400ms;

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-2xl: 48px;
    --spacing-3xl: 64px;

    /* Container widths */
    --container-max: 1200px;
    --container-narrow: 800px;
    --nav-height: 52px;
}

/* ============================================
   Base Styles
   ============================================ */

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: calc(var(--nav-height) + var(--spacing-lg));
}

body {
    font: var(--md-sys-typescale-body-large);
    background-color: var(--md-sys-color-background);
    color: var(--md-sys-color-on-background);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

::selection {
    background-color: var(--md-sys-color-primary-container);
    color: var(--md-sys-color-on-primary-container);
}

a {
    color: var(--md-sys-color-primary);
    text-decoration: none;
    transition: color var(--md-sys-motion-duration-short) var(--md-sys-motion-easing-standard);
}

a:hover {
    color: var(--md-sys-color-on-primary-container);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* ============================================
   Navigation - Apple Developer Style
   ============================================ */

.top-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(15, 23, 42, 0.85);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid var(--md-sys-color-outline-variant);
    z-index: 1000;
}

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

.nav-brand {
    font: var(--md-sys-typescale-title-medium);
    color: var(--md-sys-color-on-surface);
    font-weight: 600;
    letter-spacing: -0.01em;
}

.nav-brand:hover {
    color: var(--md-sys-color-primary);
}

.nav-links {
    display: flex;
    gap: var(--spacing-lg);
    align-items: center;
}

.nav-link {
    font: var(--md-sys-typescale-label-large);
    color: var(--md-sys-color-on-surface-variant);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--md-sys-shape-corner-small);
    transition: all var(--md-sys-motion-duration-short) var(--md-sys-motion-easing-standard);
}

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

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

.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
    color: var(--md-sys-color-on-surface);
    border-radius: var(--md-sys-shape-corner-small);
}

.nav-toggle:hover {
    background-color: var(--md-sys-color-surface-container);
}

/* ============================================
   Hero Section
   ============================================ */

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: calc(var(--nav-height) + var(--spacing-3xl)) var(--spacing-lg) var(--spacing-3xl);
    /* Material 3 dark theme base - Navy blue gradient */
    background: linear-gradient(180deg, #0f172a 0%, #1e293b 100%);
}

.hero-content {
    max-width: var(--container-max);
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.hero-eyebrow {
    font: var(--md-sys-typescale-label-large);
    color: var(--md-sys-color-primary);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--spacing-md);
}

.hero-title {
    font: var(--md-sys-typescale-display-large);
    color: var(--md-sys-color-on-surface);
    margin-bottom: var(--spacing-lg);
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font: var(--md-sys-typescale-body-large);
    color: var(--md-sys-color-on-surface-variant);
    font-size: 1.125rem;
    line-height: 1.7;
    margin-bottom: var(--spacing-xl);
}

.hero-subtitle strong {
    color: var(--md-sys-color-on-surface);
    font-weight: 500;
}

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

.hero-affiliations {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font: var(--md-sys-typescale-body-medium);
}

.affiliation-label {
    color: var(--md-sys-color-on-surface-variant);
}

.affiliation-org {
    color: var(--md-sys-color-on-surface);
    font-weight: 500;
}

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

.profile-image-container {
    position: relative;
    width: 320px;
    height: 320px;
    border-radius: var(--md-sys-shape-corner-extra-large);
    overflow: hidden;
    background: var(--md-sys-color-surface-container);
    box-shadow: var(--md-sys-elevation-3);
}

.profile-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.profile-placeholder {
    display: none;
    width: 100%;
    height: 100%;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #1e293b, #334155);
}

.profile-placeholder .material-symbols-outlined {
    font-size: 120px;
    color: var(--md-sys-color-on-primary-container);
    opacity: 0.4;
}

/* ============================================
   Buttons
   ============================================ */

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    font: var(--md-sys-typescale-label-large);
    border-radius: var(--md-sys-shape-corner-large);
    transition: all var(--md-sys-motion-duration-medium) var(--md-sys-motion-easing-emphasized);
    border: none;
    cursor: pointer;
}

.btn .material-symbols-outlined {
    font-size: 20px;
}

.btn-primary {
    background-color: #6366f1;
    color: #ffffff;
}

.btn-primary:hover {
    background-color: #818cf8;
    color: #ffffff;
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
}

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

.btn-secondary:hover {
    background-color: var(--md-sys-color-surface-container-high);
    box-shadow: var(--md-sys-elevation-1);
}

.btn-outline {
    background-color: transparent;
    color: var(--md-sys-color-primary);
    border: 1px solid var(--md-sys-color-outline);
}

.btn-outline:hover {
    background-color: rgba(99, 102, 241, 0.15);
    border-color: var(--md-sys-color-primary);
    color: var(--md-sys-color-primary);
}

/* ============================================
   Sections
   ============================================ */

.section {
    padding: var(--spacing-3xl) var(--spacing-lg);
}

.section-container {
    max-width: var(--container-max);
    margin: 0 auto;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.section-title {
    font: var(--md-sys-typescale-headline-large);
    color: var(--md-sys-color-on-surface);
    margin-bottom: var(--spacing-sm);
}

.section-subtitle {
    font: var(--md-sys-typescale-body-large);
    color: var(--md-sys-color-on-surface-variant);
}

.section-footer {
    text-align: center;
    margin-top: var(--spacing-2xl);
}

/* ============================================
   Research Section
   ============================================ */

.research-section {
    background-color: var(--md-sys-color-background);
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.research-card {
    background: var(--md-sys-color-surface);
    border: 1px solid var(--md-sys-color-outline-variant);
    border-radius: var(--md-sys-shape-corner-large);
    padding: var(--spacing-xl);
    transition: all var(--md-sys-motion-duration-medium) var(--md-sys-motion-easing-emphasized);
}

.research-card:hover {
    border-color: var(--md-sys-color-primary);
    box-shadow: var(--md-sys-elevation-2);
    transform: translateY(-2px);
}

.research-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--md-sys-shape-corner-medium);
    background: var(--md-sys-color-primary-container);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-lg);
}

.research-icon .material-symbols-outlined {
    font-size: 28px;
    color: var(--md-sys-color-on-primary-container);
}

.research-card h3 {
    font: var(--md-sys-typescale-title-large);
    color: var(--md-sys-color-on-surface);
    margin-bottom: var(--spacing-md);
}

.research-card p {
    font: var(--md-sys-typescale-body-medium);
    color: var(--md-sys-color-on-surface-variant);
    margin-bottom: var(--spacing-lg);
}

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

.research-tags li {
    font: var(--md-sys-typescale-label-medium);
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--md-sys-color-surface-container);
    color: var(--md-sys-color-on-surface-variant);
    border-radius: var(--md-sys-shape-corner-extra-small);
}

/* ============================================
   Publications Section
   ============================================ */

.publications-section {
    background-color: var(--md-sys-color-surface-container-low);
}

.publications-list {
    max-width: var(--container-narrow);
    margin: 0 auto;
}

.publication-item {
    display: grid;
    grid-template-columns: 80px 1fr;
    gap: var(--spacing-lg);
    padding: var(--spacing-lg) 0;
    border-bottom: 1px solid var(--md-sys-color-outline-variant);
}

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

.publication-year {
    font: var(--md-sys-typescale-label-large);
    color: var(--md-sys-color-primary);
}

.publication-title {
    font: var(--md-sys-typescale-title-medium);
    margin-bottom: var(--spacing-sm);
}

.publication-title a {
    color: var(--md-sys-color-on-surface);
}

.publication-title a:hover {
    color: var(--md-sys-color-primary);
}

.publication-authors {
    font: var(--md-sys-typescale-body-medium);
    color: var(--md-sys-color-on-surface-variant);
    margin-bottom: var(--spacing-xs);
}

.publication-venue {
    font: var(--md-sys-typescale-body-medium);
    margin-bottom: var(--spacing-md);
}

.venue-name {
    font-style: italic;
    color: var(--md-sys-color-on-surface-variant);
}

.publication-links {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.pub-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    font: var(--md-sys-typescale-label-medium);
    color: var(--md-sys-color-primary);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--md-sys-shape-corner-small);
    background: var(--md-sys-color-surface);
    border: 1px solid var(--md-sys-color-outline-variant);
    transition: all var(--md-sys-motion-duration-short) var(--md-sys-motion-easing-standard);
}

.pub-link:hover {
    background: rgba(99, 102, 241, 0.2);
    border-color: var(--md-sys-color-primary);
    color: var(--md-sys-color-primary);
}

.pub-link .material-symbols-outlined {
    font-size: 16px;
}

/* ============================================
   Projects Section
   ============================================ */

.projects-section {
    background-color: var(--md-sys-color-background);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.project-card {
    background: var(--md-sys-color-surface);
    border: 1px solid var(--md-sys-color-outline-variant);
    border-radius: var(--md-sys-shape-corner-large);
    overflow: hidden;
    transition: all var(--md-sys-motion-duration-medium) var(--md-sys-motion-easing-emphasized);
}

.project-card:hover {
    border-color: var(--md-sys-color-primary);
    box-shadow: var(--md-sys-elevation-2);
    transform: translateY(-2px);
}

.project-image {
    height: 180px;
    background: linear-gradient(135deg, #1e293b 0%, #334155 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.project-image.placeholder .project-placeholder-icon,
.project-image:not(:has(img:not([style*="display: none"]))) .project-placeholder-icon {
    display: block;
}

.project-placeholder-icon {
    display: none;
    font-size: 48px;
    color: var(--md-sys-color-on-primary-container);
    opacity: 0.4;
}

.project-content {
    padding: var(--spacing-lg);
}

.project-tags {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.tag {
    font: var(--md-sys-typescale-label-medium);
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--md-sys-color-primary-container);
    color: var(--md-sys-color-on-primary-container);
    border-radius: var(--md-sys-shape-corner-extra-small);
}

.project-content h3 {
    font: var(--md-sys-typescale-title-medium);
    color: var(--md-sys-color-on-surface);
    margin-bottom: var(--spacing-sm);
}

.project-content p {
    font: var(--md-sys-typescale-body-medium);
    color: var(--md-sys-color-on-surface-variant);
    margin-bottom: var(--spacing-md);
}

.project-links {
    display: flex;
    gap: var(--spacing-md);
}

.project-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    font: var(--md-sys-typescale-label-medium);
    color: var(--md-sys-color-primary);
}

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

.project-link .material-symbols-outlined {
    font-size: 16px;
}

/* ============================================
   News Section
   ============================================ */

.news-section {
    background-color: var(--md-sys-color-surface-container-low);
}

.news-timeline {
    max-width: var(--container-narrow);
    margin: 0 auto;
}

.news-item {
    display: grid;
    grid-template-columns: 100px 1fr;
    gap: var(--spacing-lg);
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--md-sys-color-outline-variant);
}

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

.news-date {
    font: var(--md-sys-typescale-label-large);
    color: var(--md-sys-color-on-surface-variant);
}

.news-content {
    font: var(--md-sys-typescale-body-medium);
    color: var(--md-sys-color-on-surface);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.news-badge {
    font: var(--md-sys-typescale-label-medium);
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--md-sys-color-secondary-container);
    color: var(--md-sys-color-on-secondary-container);
    border-radius: var(--md-sys-shape-corner-extra-small);
}

/* ============================================
   Experience Section - Material 3 Cards
   ============================================ */

.experience-section {
    background-color: var(--md-sys-color-surface-container-low);
}

.experience-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.experience-card {
    background: var(--md-sys-color-surface);
    border: 1px solid var(--md-sys-color-outline-variant);
    border-radius: var(--md-sys-shape-corner-large);
    overflow: hidden;
    transition: all var(--md-sys-motion-duration-medium) var(--md-sys-motion-easing-emphasized);
    display: flex;
    flex-direction: column;
}

.experience-card:hover {
    border-color: var(--md-sys-color-primary);
    box-shadow: var(--md-sys-elevation-2);
    transform: translateY(-2px);
}

.experience-card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-lg) var(--spacing-lg) 0;
}

.experience-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--md-sys-shape-corner-medium);
    background: var(--md-sys-color-primary-container);
    display: flex;
    align-items: center;
    justify-content: center;
}

.experience-icon .material-symbols-outlined {
    font-size: 24px;
    color: var(--md-sys-color-on-primary-container);
}

.experience-badge {
    font: var(--md-sys-typescale-label-medium);
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--md-sys-color-tertiary-container);
    color: var(--md-sys-color-on-tertiary-container);
    border-radius: var(--md-sys-shape-corner-small);
}

.experience-card-content {
    padding: var(--spacing-lg);
    flex: 1;
    display: flex;
    flex-direction: column;
}

.experience-card-content h3 {
    font: var(--md-sys-typescale-title-medium);
    color: var(--md-sys-color-on-surface);
    margin-bottom: var(--spacing-xs);
}

.experience-card-content .experience-org {
    font: var(--md-sys-typescale-body-medium);
    color: var(--md-sys-color-primary);
    margin-bottom: var(--spacing-xs);
}

.experience-card-content .experience-period {
    font: var(--md-sys-typescale-label-medium);
    color: var(--md-sys-color-on-surface-variant);
    margin-bottom: var(--spacing-md);
}

.experience-highlights {
    list-style: none;
    padding: 0;
    margin: 0;
    flex: 1;
}

.experience-highlights li {
    font: var(--md-sys-typescale-body-small);
    color: var(--md-sys-color-on-surface-variant);
    padding: var(--spacing-xs) 0;
    padding-left: var(--spacing-md);
    position: relative;
    line-height: 1.5;
}

.experience-highlights li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 10px;
    width: 4px;
    height: 4px;
    background: var(--md-sys-color-primary);
    border-radius: 50%;
}

@media (max-width: 1024px) {
    .experience-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .experience-grid {
        grid-template-columns: 1fr;
    }
}

/* ============================================
   Contact Section
   ============================================ */

.contact-section {
    background-color: var(--md-sys-color-background);
}

.contact-grid {
    display: flex;
    justify-content: center;
    gap: var(--spacing-xl);
    max-width: 500px;
    margin: 0 auto;
}

.contact-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-lg);
    background: var(--md-sys-color-surface);
    border: 1px solid var(--md-sys-color-outline-variant);
    border-radius: var(--md-sys-shape-corner-extra-large);
    text-align: center;
    transition: all var(--md-sys-motion-duration-medium) var(--md-sys-motion-easing-emphasized);
    min-width: 100px;
}

.contact-card:hover {
    border-color: var(--md-sys-color-primary);
    background: rgba(99, 102, 241, 0.15);
    transform: translateY(-4px) scale(1.05);
    box-shadow: 0 8px 24px rgba(99, 102, 241, 0.25);
}

.contact-card .material-symbols-outlined,
.contact-icon-svg {
    font-size: 32px;
    width: 32px;
    height: 32px;
    color: var(--md-sys-color-primary);
    transition: all var(--md-sys-motion-duration-medium) var(--md-sys-motion-easing-emphasized);
}

.contact-card:hover .material-symbols-outlined,
.contact-card:hover .contact-icon-svg {
    color: #c7d2fe;
    transform: scale(1.1);
}

.contact-label {
    font: var(--md-sys-typescale-label-large);
    color: var(--md-sys-color-on-surface-variant);
    transition: color var(--md-sys-motion-duration-short) var(--md-sys-motion-easing-standard);
}

.contact-card:hover .contact-label {
    color: #e0e7ff;
}

/* ============================================
   Footer
   ============================================ */

.footer {
    padding: var(--spacing-2xl) var(--spacing-lg);
    background-color: var(--md-sys-color-surface-container);
    text-align: center;
}

.footer-container {
    max-width: var(--container-max);
    margin: 0 auto;
}

.footer-text {
    font: var(--md-sys-typescale-body-medium);
    color: var(--md-sys-color-on-surface-variant);
    margin-bottom: var(--spacing-xs);
}

.footer-meta {
    font: var(--md-sys-typescale-label-medium);
    color: var(--md-sys-color-outline);
}

/* ============================================
   Responsive Design
   ============================================ */

@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: var(--spacing-2xl);
    }

    .hero-text {
        order: 2;
    }

    .hero-image {
        order: 1;
    }

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

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

    .profile-image-container {
        width: 240px;
        height: 240px;
    }

    .research-grid,
    .projects-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

@media (max-width: 768px) {
    :root {
        --nav-height: 56px;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        flex-direction: column;
        background: rgba(15, 23, 42, 0.98);
        backdrop-filter: saturate(180%) blur(20px);
        -webkit-backdrop-filter: saturate(180%) blur(20px);
        border-bottom: 1px solid var(--md-sys-color-outline-variant);
        padding: var(--spacing-md);
        gap: 0;
    }

    .nav-links.active {
        display: flex;
    }

    .nav-link {
        padding: var(--spacing-md);
        width: 100%;
        text-align: center;
    }

    .nav-toggle {
        display: flex;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .research-grid,
    .projects-grid {
        grid-template-columns: 1fr;
    }

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

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

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

    .profile-image-container {
        width: 200px;
        height: 200px;
    }
}

@media (max-width: 480px) {
    .hero {
        padding-left: var(--spacing-md);
        padding-right: var(--spacing-md);
    }

    .section {
        padding: var(--spacing-2xl) var(--spacing-md);
    }

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

    .hero-actions {
        flex-direction: column;
        align-items: stretch;
    }

    .btn {
        justify-content: center;
    }
}

/* ============================================
   Blog Styles (for blog.html)
   ============================================ */

.blog-header {
    padding: calc(var(--nav-height) + var(--spacing-3xl)) var(--spacing-lg) var(--spacing-2xl);
    background: var(--md-sys-color-surface-container-low);
    text-align: center;
}

.blog-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
}

.blog-card {
    background: var(--md-sys-color-surface);
    border: 1px solid var(--md-sys-color-outline-variant);
    border-radius: var(--md-sys-shape-corner-large);
    overflow: hidden;
    transition: all var(--md-sys-motion-duration-medium) var(--md-sys-motion-easing-emphasized);
}

.blog-card:hover {
    border-color: var(--md-sys-color-primary);
    box-shadow: var(--md-sys-elevation-2);
    transform: translateY(-2px);
}

.blog-card-content {
    padding: var(--spacing-lg);
}

.blog-meta {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.blog-date {
    font: var(--md-sys-typescale-label-medium);
    color: var(--md-sys-color-on-surface-variant);
}

.blog-category {
    font: var(--md-sys-typescale-label-medium);
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--md-sys-color-secondary-container);
    color: var(--md-sys-color-on-secondary-container);
    border-radius: var(--md-sys-shape-corner-extra-small);
}

.blog-card h3 {
    font: var(--md-sys-typescale-title-medium);
    color: var(--md-sys-color-on-surface);
    margin-bottom: var(--spacing-sm);
}

.blog-card h3 a {
    color: inherit;
}

.blog-card h3 a:hover {
    color: var(--md-sys-color-primary);
}

.blog-excerpt {
    font: var(--md-sys-typescale-body-medium);
    color: var(--md-sys-color-on-surface-variant);
    margin-bottom: var(--spacing-md);
}

.blog-read-more {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    font: var(--md-sys-typescale-label-large);
    color: var(--md-sys-color-primary);
}

.blog-read-more .material-symbols-outlined {
    font-size: 18px;
    transition: transform var(--md-sys-motion-duration-short) var(--md-sys-motion-easing-standard);
}

.blog-card:hover .blog-read-more .material-symbols-outlined {
    transform: translateX(4px);
}

/* Blog Post Styles */
.blog-post {
    max-width: var(--container-narrow);
    margin: 0 auto;
    padding: calc(var(--nav-height) + var(--spacing-2xl)) var(--spacing-lg) var(--spacing-3xl);
}

.blog-post-header {
    margin-bottom: var(--spacing-2xl);
}

.blog-post-title {
    font: var(--md-sys-typescale-headline-large);
    color: var(--md-sys-color-on-surface);
    margin-bottom: var(--spacing-md);
}

.blog-post-meta {
    display: flex;
    gap: var(--spacing-lg);
    color: var(--md-sys-color-on-surface-variant);
    font: var(--md-sys-typescale-body-medium);
}

.blog-post-content {
    font: var(--md-sys-typescale-body-large);
    line-height: 1.8;
}

.blog-post-content h2 {
    font: var(--md-sys-typescale-headline-medium);
    color: var(--md-sys-color-on-surface);
    margin-top: var(--spacing-2xl);
    margin-bottom: var(--spacing-md);
}

.blog-post-content h3 {
    font: var(--md-sys-typescale-title-large);
    color: var(--md-sys-color-on-surface);
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
}

.blog-post-content p {
    margin-bottom: var(--spacing-md);
    color: var(--md-sys-color-on-surface-variant);
}

.blog-post-content code {
    font-family: 'Roboto Mono', monospace;
    font-size: 0.9em;
    background: var(--md-sys-color-surface-container);
    padding: 2px 6px;
    border-radius: var(--md-sys-shape-corner-extra-small);
}

.blog-post-content pre {
    background: var(--md-sys-color-surface-container-highest);
    padding: var(--spacing-lg);
    border-radius: var(--md-sys-shape-corner-medium);
    overflow-x: auto;
    margin-bottom: var(--spacing-lg);
}

.blog-post-content pre code {
    background: none;
    padding: 0;
}

.blog-post-content ul,
.blog-post-content ol {
    margin-bottom: var(--spacing-md);
    padding-left: var(--spacing-xl);
    color: var(--md-sys-color-on-surface-variant);
}

.blog-post-content li {
    margin-bottom: var(--spacing-sm);
}

.blog-post-content blockquote {
    border-left: 4px solid var(--md-sys-color-primary);
    padding-left: var(--spacing-lg);
    margin: var(--spacing-lg) 0;
    font-style: italic;
    color: var(--md-sys-color-on-surface-variant);
}

.blog-post-content img {
    border-radius: var(--md-sys-shape-corner-medium);
    margin: var(--spacing-lg) 0;
}

@media (max-width: 768px) {
    .blog-grid {
        grid-template-columns: 1fr;
    }
}

/* ============================================
   Time-Based Hero Background
   ============================================ */

.hero {
    position: relative;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 0;
    /* Material 3 dark theme fallback - Deep navy */
    background-color: #0f172a;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    transition: background-image 0.8s ease-in-out, opacity 1s ease-in-out;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    /* Material 3 dark theme - Navy/Black gradient overlay */
    background: linear-gradient(
        135deg,
        rgba(10, 15, 26, 0.55) 0%,
        rgba(15, 23, 42, 0.45) 50%,
        rgba(20, 30, 48, 0.50) 100%
    );
}

/* Time-specific overlays - Dark theme with moderate opacity for text readability */
.hero-background.time-morning .hero-overlay {
    background: linear-gradient(
        135deg,
        rgba(20, 30, 48, 0.50) 0%,
        rgba(30, 41, 59, 0.40) 100%
    );
}

.hero-background.time-afternoon .hero-overlay {
    background: linear-gradient(
        135deg,
        rgba(15, 23, 42, 0.50) 0%,
        rgba(20, 40, 70, 0.45) 100%
    );
}

.hero-background.time-evening .hero-overlay {
    background: linear-gradient(
        135deg,
        rgba(20, 18, 50, 0.55) 0%,
        rgba(35, 32, 90, 0.45) 100%
    );
}

.hero-background.time-night .hero-overlay {
    background: linear-gradient(
        135deg,
        rgba(2, 6, 23, 0.60) 0%,
        rgba(10, 15, 30, 0.50) 100%
    );
}

/* Dark theme hero text enhancements */
.hero .hero-eyebrow {
    color: #a5b4fc;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.6);
}

.hero .hero-title {
    color: #ffffff;
    text-shadow: 0 2px 12px rgba(0, 0, 0, 0.5), 0 4px 20px rgba(0, 0, 0, 0.3);
}

.hero .hero-subtitle {
    color: #e2e8f0;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.5);
}

.hero .hero-subtitle strong {
    color: #ffffff;
}

.hero .affiliation-label {
    color: #e2e8f0;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.6);
}

.hero .affiliation-org {
    color: #ffffff;
    font-weight: 600;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.6);
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero-time-indicator {
    position: absolute;
    bottom: var(--spacing-lg);
    right: var(--spacing-lg);
    font: var(--md-sys-typescale-label-medium);
    color: rgba(255, 255, 255, 0.5);
    z-index: 1;
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

/* ============================================
   Astrophotography Page - Dark Theme
   ============================================ */

body.dark-theme {
    --md-sys-color-background: #0d1117;
    --md-sys-color-surface: #161b22;
    --md-sys-color-surface-container: #1c2128;
    --md-sys-color-surface-container-low: #141920;
    --md-sys-color-surface-container-high: #242a33;
    --md-sys-color-on-surface: #e6edf3;
    --md-sys-color-on-surface-variant: #8b949e;
    --md-sys-color-outline: #3d444d;
    --md-sys-color-outline-variant: #2d333b;
    --md-sys-color-primary: #79c0ff;
    --md-sys-color-primary-container: #1f3a5f;
    --md-sys-color-on-primary-container: #c8e1ff;

    background-color: var(--md-sys-color-background);
}

.top-nav.dark {
    background: rgba(13, 17, 23, 0.85);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom-color: var(--md-sys-color-outline-variant);
}

.top-nav.dark .nav-brand,
.top-nav.dark .nav-link {
    color: var(--md-sys-color-on-surface);
}

.top-nav.dark .nav-link:hover {
    background-color: var(--md-sys-color-surface-container);
}

.top-nav.dark .nav-link.active {
    color: var(--md-sys-color-primary);
}

.footer.dark {
    background-color: var(--md-sys-color-surface);
    border-top: 1px solid var(--md-sys-color-outline-variant);
}

.footer.dark .footer-text,
.footer.dark .footer-meta,
.footer.dark .footer-meta a {
    color: var(--md-sys-color-on-surface-variant);
}

/* Astrophotography Hero */
.astro-hero {
    position: relative;
    height: 60vh;
    min-height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.astro-hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, #0a0a1a 0%, #1a1a3a 50%, #0d1117 100%);
    background-size: cover;
    background-position: center;
}

.astro-hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(ellipse at center, transparent 0%, rgba(0,0,0,0.5) 100%);
}

.astro-hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: #fff;
    padding: var(--spacing-lg);
}

.astro-hero-icon {
    font-size: 48px;
    margin-bottom: var(--spacing-md);
    color: #ffd700;
    animation: twinkle 2s ease-in-out infinite;
}

@keyframes twinkle {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.7; transform: scale(0.95); }
}

.astro-hero h1 {
    font: var(--md-sys-typescale-display-medium);
    margin-bottom: var(--spacing-sm);
    letter-spacing: 0.05em;
}

.astro-hero p {
    font: var(--md-sys-typescale-body-large);
    opacity: 0.8;
}

/* Astrophotography Gallery Section */
.astro-gallery-section {
    background-color: var(--md-sys-color-background);
}

.astro-featured-container {
    margin-bottom: var(--spacing-2xl);
}

.astro-featured-item {
    position: relative;
    border-radius: var(--md-sys-shape-corner-extra-large);
    overflow: hidden;
    background: var(--md-sys-color-surface);
}

.astro-featured-item img {
    width: 100%;
    height: 500px;
    object-fit: cover;
}

.astro-featured-item figcaption {
    padding: var(--spacing-xl);
}

.astro-featured-item h2 {
    font: var(--md-sys-typescale-headline-medium);
    color: var(--md-sys-color-on-surface);
    margin-bottom: var(--spacing-md);
}

.astro-meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    color: var(--md-sys-color-on-surface-variant);
    font: var(--md-sys-typescale-body-medium);
}

.astro-meta span {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.astro-meta .material-symbols-outlined {
    font-size: 18px;
    color: var(--md-sys-color-primary);
}

.astro-description {
    font: var(--md-sys-typescale-body-large);
    color: var(--md-sys-color-on-surface-variant);
}

/* Gallery Grid */
.astro-gallery-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-2xl);
}

.astro-gallery-item {
    position: relative;
    border-radius: var(--md-sys-shape-corner-large);
    overflow: hidden;
    background: var(--md-sys-color-surface);
    aspect-ratio: 1;
    cursor: pointer;
    transition: transform var(--md-sys-motion-duration-medium) var(--md-sys-motion-easing-emphasized);
}

.astro-gallery-item:hover {
    transform: scale(1.02);
    z-index: 1;
}

.astro-gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--md-sys-motion-duration-long) var(--md-sys-motion-easing-emphasized);
}

.astro-gallery-item:hover img {
    transform: scale(1.1);
}

.astro-gallery-item figcaption {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: var(--spacing-md);
    background: linear-gradient(transparent, rgba(0,0,0,0.8));
    color: #fff;
    transform: translateY(100%);
    transition: transform var(--md-sys-motion-duration-medium) var(--md-sys-motion-easing-emphasized);
}

.astro-gallery-item:hover figcaption {
    transform: translateY(0);
}

.astro-gallery-item h3 {
    font: var(--md-sys-typescale-title-medium);
    margin-bottom: var(--spacing-xs);
}

.astro-gallery-item p {
    font: var(--md-sys-typescale-label-medium);
    opacity: 0.8;
}

/* Placeholder for missing images */
.astro-gallery-item.placeholder,
.astro-featured-item.placeholder {
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #1a1a3a 0%, #2a2a5a 100%);
}

.astro-gallery-item.placeholder::before,
.astro-featured-item.placeholder::before {
    content: 'auto_awesome';
    font-family: 'Material Symbols Outlined';
    font-size: 48px;
    color: rgba(255, 255, 255, 0.2);
}

/* Equipment Info Cards */
.astro-info-section {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-2xl);
}

.astro-info-card {
    background: var(--md-sys-color-surface);
    border: 1px solid var(--md-sys-color-outline-variant);
    border-radius: var(--md-sys-shape-corner-large);
    padding: var(--spacing-xl);
}

.astro-info-card h3 {
    font: var(--md-sys-typescale-title-medium);
    color: var(--md-sys-color-on-surface);
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.astro-info-card h3 .material-symbols-outlined {
    color: var(--md-sys-color-primary);
}

.astro-info-card ul {
    list-style: none;
}

.astro-info-card li {
    font: var(--md-sys-typescale-body-medium);
    color: var(--md-sys-color-on-surface-variant);
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid var(--md-sys-color-outline-variant);
}

.astro-info-card li:last-child {
    border-bottom: none;
}

.astro-note {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
    font: var(--md-sys-typescale-body-medium);
    color: var(--md-sys-color-on-surface-variant);
    font-style: italic;
    max-width: var(--container-narrow);
    margin: 0 auto;
    text-align: center;
    justify-content: center;
}

.astro-note .material-symbols-outlined {
    color: var(--md-sys-color-primary);
    flex-shrink: 0;
}

/* Section icon */
.section-icon {
    font-size: 32px;
    color: var(--md-sys-color-primary);
    margin-bottom: var(--spacing-sm);
}

/* Responsive Astrophotography */
@media (max-width: 1024px) {
    .astro-gallery-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .astro-info-section {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .astro-hero {
        height: 50vh;
        min-height: 300px;
    }

    .astro-hero h1 {
        font-size: 2rem;
    }

    .astro-gallery-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .astro-featured-item img {
        height: 300px;
    }

    .astro-info-section {
        grid-template-columns: 1fr;
    }

    .astro-meta {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

    .top-nav.dark .nav-links {
        background: rgba(13, 17, 23, 0.98);
    }
}

@media (max-width: 480px) {
    .astro-gallery-grid {
        grid-template-columns: 1fr;
    }

    .astro-gallery-item {
        aspect-ratio: 16/9;
    }
}