/* ArXiv Word Cloud Evolution - Styles */

:root {
    /* Color Palette - Dark Theme */
    --bg-primary: #0a0e17;
    --bg-secondary: #111827;
    --bg-tertiary: #1f2937;
    --bg-card: #1a1f2e;
    
    --text-primary: #f9fafb;
    --text-secondary: #9ca3af;
    --text-muted: #6b7280;
    
    --accent-blue: #3b82f6;
    --accent-cyan: #06b6d4;
    --accent-purple: #8b5cf6;
    --accent-pink: #ec4899;
    --accent-green: #10b981;
    --accent-red: #ef4444;
    --accent-orange: #f97316;
    
    --gradient-primary: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
    --gradient-accent: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
    
    /* Typography */
    --font-display: 'Space Grotesk', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Border radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.4);
    --shadow-glow: 0 0 20px rgba(59, 130, 246, 0.3);
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 300ms ease;
    --transition-slow: 500ms ease;
}

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

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

body {
    font-family: var(--font-display);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
    
    /* Subtle grid background */
    background-image: 
        radial-gradient(ellipse at top, rgba(59, 130, 246, 0.1) 0%, transparent 50%),
        linear-gradient(to bottom, var(--bg-primary), var(--bg-secondary));
}

/* App Container */
.app-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Header */
.header {
    text-align: center;
    padding: var(--spacing-2xl) 0;
}

.title {
    font-size: 2.5rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-sm);
    letter-spacing: -0.02em;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.125rem;
    font-weight: 400;
}

/* Category Tabs */
.category-tabs {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.tab-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    background: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    color: var(--text-secondary);
    font-family: var(--font-display);
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-normal);
}

.tab-btn:hover {
    background: var(--bg-tertiary);
    border-color: var(--accent-blue);
    color: var(--text-primary);
}

.tab-btn.active {
    background: var(--gradient-primary);
    border-color: transparent;
    color: white;
    box-shadow: var(--shadow-glow);
}

.tab-icon {
    font-size: 1.25rem;
}

.tab-label {
    font-weight: 500;
}

.tab-code {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    opacity: 0.7;
}

/* Word Cloud Container */
.wordcloud-wrapper {
    flex: 1;
    display: flex;
    justify-content: center;
    margin-bottom: var(--spacing-xl);
}

.wordcloud-container {
    position: relative;
    width: 100%;
    max-width: 1200px;
    height: 600px;
    background: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-xl);
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

.wordcloud-canvas {
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

.wordcloud-canvas.hidden {
    display: none;
}

.wordcloud-canvas svg {
    width: 100%;
    height: 100%;
}

/* Word styling */
.word {
    cursor: pointer;
    transition: transform var(--transition-fast);
}

.word:hover {
    transform: scale(1.1);
}

/* Loading Overlay */
.loading-overlay {
    position: absolute;
    inset: 0;
    background: rgba(10, 14, 23, 0.9);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-md);
    z-index: 10;
}

.loading-overlay.hidden {
    display: none;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--bg-tertiary);
    border-top-color: var(--accent-blue);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Timeline Section */
.timeline-section {
    padding: var(--spacing-lg);
    background: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-xl);
    margin-bottom: var(--spacing-xl);
}

.timeline-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.timeline-header h3 {
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.current-period {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
}

.period-label {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--accent-cyan);
}

.period-papers {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.timeline-container {
    height: 60px;
    margin-bottom: var(--spacing-md);
}

.timeline-controls {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
}

.control-btn {
    width: 40px;
    height: 40px;
    background: var(--bg-tertiary);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.control-btn:hover {
    background: var(--accent-blue);
    color: white;
    border-color: var(--accent-blue);
}

.control-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* Timeline SVG styling */
.timeline-axis text {
    fill: var(--text-muted);
    font-size: 10px;
}

.timeline-axis line,
.timeline-axis path {
    stroke: rgba(255, 255, 255, 0.2);
}

.timeline-scrubber {
    fill: var(--accent-cyan);
    cursor: grab;
    filter: drop-shadow(0 0 10px rgba(6, 182, 212, 0.5));
}

.timeline-scrubber:active {
    cursor: grabbing;
}

.timeline-track {
    fill: rgba(255, 255, 255, 0.1);
    rx: 4;
}

/* Statistics Panel */
.stats-panel {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    text-align: center;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    font-family: var(--font-mono);
}

.stat-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-top: var(--spacing-xs);
}

.stat-card.emerging .stat-value {
    color: var(--accent-green);
}

.stat-card.declining .stat-value {
    color: var(--accent-red);
}

/* Modal */
.modal {
    position: fixed;
    inset: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 100;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.modal.visible {
    opacity: 1;
    visibility: visible;
}

.modal-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    width: 90%;
    max-width: 700px;
    background: var(--bg-secondary);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    transform: scale(0.9);
    transition: transform var(--transition-normal);
}

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

.modal-close {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    width: 32px;
    height: 32px;
    background: transparent;
    border: none;
    color: var(--text-muted);
    font-size: 1.5rem;
    cursor: pointer;
    transition: color var(--transition-fast);
}

.modal-close:hover {
    color: var(--text-primary);
}

.modal-title {
    font-size: 1.75rem;
    font-weight: 700;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-lg);
}

.evolution-chart {
    height: 200px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-lg);
}

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

.term-stat {
    display: flex;
    justify-content: space-between;
    padding: var(--spacing-sm);
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
}

.term-stat .label {
    color: var(--text-muted);
}

.term-stat .value {
    color: var(--text-primary);
    font-weight: 500;
    font-family: var(--font-mono);
}

/* Footer */
.footer {
    text-align: center;
    padding: var(--spacing-lg) 0;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-content {
    color: var(--text-muted);
    font-size: 0.875rem;
}

.footer a {
    color: var(--accent-blue);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.footer a:hover {
    color: var(--accent-cyan);
}

/* Responsive */
@media (max-width: 768px) {
    .title {
        font-size: 1.75rem;
    }
    
    .category-tabs {
        flex-direction: column;
    }
    
    .wordcloud-container {
        height: 400px;
    }
    
    .stats-panel {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .term-stats {
        grid-template-columns: 1fr;
    }
}

/* Tooltip */
.tooltip {
    position: absolute;
    background: var(--bg-secondary);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 0.875rem;
    pointer-events: none;
    z-index: 50;
    box-shadow: var(--shadow-lg);
}

.tooltip-title {
    font-weight: 600;
    color: var(--text-primary);
}

.tooltip-score {
    color: var(--text-muted);
    font-family: var(--font-mono);
    font-size: 0.75rem;
}