/* ========================================
   Plant Cell Atlas - Stylesheet
   ======================================== */

/* CSS Variables */
:root {
    --color-bg: #0d1a0f;
    --color-bg-light: #1a2e1c;
    --color-bg-accent: #243826;
    --color-primary: #4ade80;
    --color-primary-dark: #22c55e;
    --color-secondary: #a7f3d0;
    --color-accent: #fbbf24;
    --color-text: #f0fdf4;
    --color-text-muted: #86efac;
    --color-text-dark: #1a2e1c;
    --color-border: rgba(74, 222, 128, 0.2);
    
    --font-display: 'Cormorant Garamond', Georgia, serif;
    --font-body: 'DM Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    --radius-xl: 24px;
}

/* Reset & Base */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

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

body {
    font-family: var(--font-body);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    overflow-x: hidden;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 600;
    line-height: 1.2;
}

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

a:hover {
    color: var(--color-secondary);
}

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

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Navigation */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 16px 0;
    background: linear-gradient(to bottom, rgba(13, 26, 15, 0.95), rgba(13, 26, 15, 0));
    backdrop-filter: blur(10px);
    transition: background var(--transition-base);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-family: var(--font-display);
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--color-text);
}

.nav-logo:hover {
    color: var(--color-text);
}

.logo-icon {
    font-size: 1.6rem;
}

.nav-links {
    display: flex;
    gap: 32px;
    list-style: none;
}

.nav-links a {
    color: var(--color-text-muted);
    font-size: 0.95rem;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.nav-links a:hover {
    color: var(--color-text);
}

/* Language Switcher */
.lang-switcher {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-left: 24px;
}

.lang-btn {
    background: none;
    border: none;
    color: var(--color-text-muted);
    font-family: var(--font-body);
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    padding: 4px 8px;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.lang-btn:hover {
    color: var(--color-text);
}

.lang-btn.active {
    color: var(--color-primary);
    background: rgba(74, 222, 128, 0.1);
}

.lang-divider {
    color: var(--color-border);
    font-size: 0.85rem;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--color-text);
    transition: var(--transition-fast);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
    padding: 120px 24px 80px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    overflow: hidden;
}

.cell {
    position: absolute;
    border-radius: 50%;
    background: radial-gradient(ellipse at 30% 30%, var(--color-primary), transparent 70%);
    opacity: 0.08;
    animation: float 20s infinite ease-in-out;
}

.cell-1 {
    width: 600px;
    height: 600px;
    top: -200px;
    right: -200px;
    animation-delay: 0s;
}

.cell-2 {
    width: 400px;
    height: 400px;
    bottom: -100px;
    left: -150px;
    animation-delay: -5s;
}

.cell-3 {
    width: 300px;
    height: 300px;
    top: 50%;
    left: 10%;
    animation-delay: -10s;
}

.cell-4 {
    width: 250px;
    height: 250px;
    top: 20%;
    right: 20%;
    animation-delay: -15s;
}

.cell-5 {
    width: 200px;
    height: 200px;
    bottom: 30%;
    right: 10%;
    animation-delay: -8s;
}

.cell-6 {
    width: 350px;
    height: 350px;
    top: 60%;
    left: 50%;
    animation-delay: -12s;
}

@keyframes float {
    0%, 100% {
        transform: translate(0, 0) scale(1);
    }
    25% {
        transform: translate(20px, -30px) scale(1.05);
    }
    50% {
        transform: translate(-10px, 20px) scale(0.95);
    }
    75% {
        transform: translate(-30px, -10px) scale(1.02);
    }
}

.hero-content {
    text-align: center;
    position: relative;
    z-index: 1;
    max-width: 800px;
}

.hero-tag {
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 3px;
    color: var(--color-primary);
    margin-bottom: 24px;
    animation: fadeInUp 0.8s ease forwards;
    animation-delay: 0.2s;
    opacity: 0;
}

.hero-title {
    font-size: clamp(3rem, 10vw, 7rem);
    font-weight: 400;
    margin-bottom: 24px;
    line-height: 1;
}

.title-line {
    display: block;
    animation: fadeInUp 0.8s ease forwards;
    opacity: 0;
}

.title-line:nth-child(1) {
    animation-delay: 0.4s;
}

.title-line:nth-child(2) {
    animation-delay: 0.6s;
    color: var(--color-primary);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-muted);
    margin-bottom: 40px;
    animation: fadeInUp 0.8s ease forwards;
    animation-delay: 0.8s;
    opacity: 0;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    animation: fadeInUp 0.8s ease forwards;
    animation-delay: 1s;
    opacity: 0;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-scroll {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: var(--color-text-muted);
    font-size: 0.85rem;
    animation: fadeIn 1s ease forwards;
    animation-delay: 1.5s;
    opacity: 0;
}

@keyframes fadeIn {
    to { opacity: 1; }
}

.scroll-indicator {
    width: 24px;
    height: 40px;
    border: 2px solid var(--color-border);
    border-radius: 12px;
    position: relative;
}

.scroll-indicator::after {
    content: '';
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 8px;
    background: var(--color-primary);
    border-radius: 2px;
    animation: scrollBounce 2s infinite;
}

@keyframes scrollBounce {
    0%, 100% { transform: translateX(-50%) translateY(0); opacity: 1; }
    50% { transform: translateX(-50%) translateY(12px); opacity: 0.3; }
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    font-family: var(--font-body);
    font-size: 1rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    border: 2px solid transparent;
}

.btn-primary {
    background: var(--color-primary);
    color: var(--color-text-dark);
    border-color: var(--color-primary);
}

.btn-primary:hover {
    background: var(--color-primary-dark);
    border-color: var(--color-primary-dark);
    color: var(--color-text-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(74, 222, 128, 0.3);
}

.btn-outline {
    background: transparent;
    color: var(--color-text);
    border-color: var(--color-border);
}

.btn-outline:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.btn-outline-light {
    background: transparent;
    color: var(--color-text);
    border-color: rgba(255, 255, 255, 0.3);
}

.btn-outline-light:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--color-text);
    color: var(--color-text);
}

.btn-block {
    width: 100%;
}

/* Sections */
.section {
    padding: 120px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 64px;
}

.section-tag {
    display: inline-block;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: var(--color-primary);
    margin-bottom: 16px;
}

.section-title {
    font-size: clamp(2rem, 5vw, 3.5rem);
    margin-bottom: 16px;
}

.section-desc {
    font-size: 1.1rem;
    color: var(--color-text-muted);
    max-width: 600px;
    margin: 0 auto;
}

.section-header-light .section-title {
    color: var(--color-text);
}

/* About Section */
.about {
    background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-bg-light) 100%);
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 64px;
    align-items: center;
}

.about-content .lead {
    font-size: 1.3rem;
    color: var(--color-text);
    margin-bottom: 24px;
    line-height: 1.7;
}

.about-content p {
    color: var(--color-text-muted);
    margin-bottom: 16px;
}

.about-stats {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
}

.stat-card {
    background: var(--color-bg-accent);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 32px;
    text-align: center;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.stat-number {
    display: block;
    font-family: var(--font-display);
    font-size: 3rem;
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: 8px;
}

.stat-label {
    font-size: 0.95rem;
    color: var(--color-text-muted);
}

/* Atlas Section */
.atlas {
    background: var(--color-bg-light);
}

.atlas-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.atlas-card {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 32px;
    transition: all var(--transition-base);
    display: flex;
    flex-direction: column;
}

.atlas-card:hover {
    border-color: var(--color-primary);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.atlas-icon {
    width: 48px;
    height: 48px;
    color: var(--color-primary);
    margin-bottom: 20px;
}

.atlas-icon svg {
    width: 100%;
    height: 100%;
}

.atlas-card h3 {
    font-size: 1.3rem;
    margin-bottom: 8px;
}

.atlas-card h3 em {
    font-style: italic;
    font-weight: 400;
    color: var(--color-text-muted);
    font-size: 0.9em;
}

.atlas-card p {
    color: var(--color-text-muted);
    font-size: 0.95rem;
    margin-bottom: 16px;
    flex-grow: 1;
}

.atlas-meta {
    display: inline-block;
    font-size: 0.85rem;
    color: var(--color-primary);
    background: rgba(74, 222, 128, 0.1);
    padding: 4px 12px;
    border-radius: 100px;
    margin-bottom: 16px;
}

.atlas-link {
    font-weight: 500;
    font-size: 0.95rem;
}

.atlas-card-more {
    background: linear-gradient(135deg, var(--color-bg-accent) 0%, var(--color-bg) 100%);
    border-style: dashed;
}

/* Research Section */
.research {
    background: var(--color-bg);
    position: relative;
}

.research::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--color-border), transparent);
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.research-grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.research-card {
    position: relative;
    padding: 40px 32px;
    background: linear-gradient(180deg, var(--color-bg-light) 0%, var(--color-bg) 100%);
    border-radius: var(--radius-lg);
    transition: transform var(--transition-base);
    border: 1px solid var(--color-border);
}

.research-card:hover {
    transform: translateY(-4px);
    border-color: var(--color-primary);
    box-shadow: var(--shadow-lg);
}

.research-card-large {
    padding: 48px 40px;
}

.research-number {
    font-family: var(--font-display);
    font-size: 4rem;
    font-weight: 600;
    color: var(--color-border);
    position: absolute;
    top: 20px;
    right: 24px;
    line-height: 1;
}

.research-tag {
    display: inline-block;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    color: var(--color-primary);
    background: rgba(74, 222, 128, 0.1);
    padding: 6px 14px;
    border-radius: 100px;
    margin-bottom: 16px;
    font-weight: 600;
}

.research-card h3 {
    font-size: 1.4rem;
    margin-bottom: 16px;
    position: relative;
    line-height: 1.3;
}

.research-lead {
    color: var(--color-text);
    font-size: 1.05rem;
    line-height: 1.7;
    margin-bottom: 24px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--color-border);
}

.research-card p {
    color: var(--color-text-muted);
    font-size: 0.95rem;
    line-height: 1.7;
}

.research-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.research-list li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 16px;
    font-size: 0.95rem;
    color: var(--color-text-muted);
    line-height: 1.6;
}

.research-list li:last-child {
    margin-bottom: 0;
}

.research-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 8px;
    width: 8px;
    height: 8px;
    background: var(--color-primary);
    border-radius: 50%;
    opacity: 0.6;
}

.research-list li strong {
    color: var(--color-text);
    font-weight: 600;
}

/* Publications Section */
.publications {
    background: linear-gradient(135deg, var(--color-bg-light) 0%, var(--color-bg-accent) 100%);
}

.pub-list {
    max-width: 900px;
    margin: 0 auto;
}

.pub-item {
    display: flex;
    gap: 24px;
    align-items: flex-start;
    padding: 32px 0;
    border-bottom: 1px solid var(--color-border);
    transition: background var(--transition-fast);
}

.pub-item:first-child {
    padding-top: 0;
}

.pub-item:hover {
    background: rgba(74, 222, 128, 0.02);
}

.pub-year {
    font-family: var(--font-display);
    font-size: 1.5rem;
    color: var(--color-primary);
    min-width: 80px;
}

.pub-content {
    flex: 1;
}

.pub-content h3 {
    font-size: 1.15rem;
    font-weight: 500;
    margin-bottom: 8px;
    line-height: 1.4;
}

.pub-authors {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    margin-bottom: 4px;
}

.pub-journal {
    font-size: 0.9rem;
    color: var(--color-secondary);
}

.pub-badge {
    display: inline-block;
    font-size: 0.7rem;
    font-style: normal;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    background: var(--color-accent);
    color: var(--color-text-dark);
    padding: 2px 8px;
    border-radius: 100px;
    margin-left: 8px;
    vertical-align: middle;
    font-weight: 600;
}

.pub-link {
    padding: 8px 16px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    font-weight: 500;
    transition: all var(--transition-fast);
}

.pub-link:hover {
    border-color: var(--color-primary);
    background: var(--color-primary);
    color: var(--color-text-dark);
}

.pub-more {
    text-align: center;
    margin-top: 48px;
}

/* Team Section */
.team {
    background: var(--color-bg);
}

.team-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
}

.team-card {
    text-align: center;
    padding: 40px 24px;
    background: var(--color-bg-light);
    border-radius: var(--radius-lg);
    transition: transform var(--transition-base);
}

.team-card:hover {
    transform: translateY(-4px);
}

.team-avatar {
    width: 100px;
    height: 100px;
    margin: 0 auto 20px;
    border-radius: 50%;
    overflow: hidden;
    background: var(--color-bg-accent);
    border: 3px solid var(--color-border);
}

.avatar-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-display);
    font-size: 1.5rem;
    color: var(--color-primary);
    background: linear-gradient(135deg, var(--color-bg-accent), var(--color-bg));
}

.team-card h3 {
    font-size: 1.15rem;
    margin-bottom: 4px;
}

.team-role {
    display: block;
    font-size: 0.85rem;
    color: var(--color-primary);
    margin-bottom: 12px;
}

.team-card p {
    font-size: 0.9rem;
    color: var(--color-text-muted);
}

/* Contact Section */
.contact {
    background: linear-gradient(180deg, var(--color-bg-light) 0%, var(--color-bg) 100%);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
}

.contact-info h2 {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.contact-info > p {
    color: var(--color-text-muted);
    margin-bottom: 40px;
    line-height: 1.7;
}

.contact-details {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.contact-item {
    display: flex;
    gap: 16px;
}

.contact-icon {
    font-size: 1.5rem;
}

.contact-item strong {
    display: block;
    margin-bottom: 4px;
    color: var(--color-text);
}

.contact-item p {
    color: var(--color-text-muted);
    font-size: 0.95rem;
}

.contact-form-wrapper {
    background: var(--color-bg-accent);
    border-radius: var(--radius-xl);
    padding: 48px;
    border: 1px solid var(--color-border);
}

.form-group {
    margin-bottom: 24px;
}

.form-group label {
    display: block;
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: 8px;
    color: var(--color-text);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 14px 16px;
    font-family: var(--font-body);
    font-size: 1rem;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text);
    transition: border-color var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-primary);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* Footer */
.footer {
    background: var(--color-bg);
    border-top: 1px solid var(--color-border);
    padding: 48px 0;
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 20px;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-family: var(--font-display);
    font-size: 1.3rem;
    font-weight: 600;
}

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

.footer-links {
    display: flex;
    gap: 32px;
}

.footer-links a {
    color: var(--color-text-muted);
    font-size: 0.9rem;
}

.footer-links a:hover {
    color: var(--color-primary);
}

/* Responsive Design */
@media (max-width: 1200px) {
    .research-grid,
    .research-grid-3 {
        grid-template-columns: 1fr;
        gap: 24px;
    }
    
    .research-card-large {
        padding: 40px 32px;
    }
}

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

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--color-bg);
        padding: 24px;
        gap: 16px;
        border-bottom: 1px solid var(--color-border);
    }
    
    .nav-links.active {
        display: flex;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .lang-switcher {
        margin-left: auto;
        margin-right: 16px;
    }
    
    .hero {
        padding: 100px 24px 60px;
    }
    
    .hero-actions {
        flex-direction: column;
        width: 100%;
        max-width: 280px;
        margin: 0 auto;
    }
    
    .section {
        padding: 80px 0;
    }
    
    .about-grid {
        grid-template-columns: 1fr;
        gap: 48px;
    }
    
    .atlas-grid {
        grid-template-columns: 1fr;
    }
    
    .research-grid {
        grid-template-columns: 1fr;
        gap: 24px;
    }
    
    .contact-grid {
        grid-template-columns: 1fr;
        gap: 48px;
    }
    
    .team-grid {
        grid-template-columns: 1fr;
        gap: 24px;
    }
    
    .pub-item {
        flex-direction: column;
        gap: 12px;
    }
    
    .pub-year {
        min-width: auto;
    }
    
    .contact-form-wrapper {
        padding: 32px 24px;
    }
}

@media (max-width: 480px) {
    .about-stats {
        grid-template-columns: 1fr;
    }
    
    .stat-card {
        padding: 24px;
    }
    
    .stat-number {
        font-size: 2.5rem;
    }
    
    .research-number {
        font-size: 3rem;
    }
}