/*
 * Paper Tracker - Research Observatory Theme
 * A refined dark interface for academic paper tracking
 */

@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500;600&family=Instrument+Sans:wght@400;500;600;700&family=Source+Serif+4:ital,wght@0,400;0,500;0,600;1,400&display=swap');

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

:root {
    /* Observatory color palette */
    --void: #08090a;
    --deep: #0c0d0f;
    --surface: #121416;
    --elevated: #1a1c1f;
    --border: #252830;
    --border-subtle: #1e2024;

    --text-bright: #f0f2f5;
    --text-primary: #c9cdd4;
    --text-secondary: #8b919c;
    --text-muted: #5c6370;

    --accent-cyan: #22d3ee;
    --accent-cyan-dim: rgba(34, 211, 238, 0.12);
    --accent-amber: #fbbf24;
    --accent-amber-dim: rgba(251, 191, 36, 0.12);
    --accent-emerald: #34d399;
    --accent-emerald-dim: rgba(52, 211, 153, 0.1);
    --accent-rose: #fb7185;

    /* Typography */
    --font-display: 'Instrument Sans', -apple-system, sans-serif;
    --font-body: 'Source Serif 4', Georgia, serif;
    --font-mono: 'JetBrains Mono', monospace;

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;

    /* Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    background-color: var(--void);
    color: var(--text-primary);
    line-height: 1.7;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Subtle background texture */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    background:
        radial-gradient(ellipse 80% 50% at 50% -20%, rgba(34, 211, 238, 0.03), transparent),
        radial-gradient(ellipse 60% 40% at 100% 100%, rgba(251, 191, 36, 0.02), transparent);
    pointer-events: none;
    z-index: -1;
}

a {
    color: var(--text-primary);
    text-decoration: none;
    transition: color 0.2s ease;
}

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

/* Selection */
::selection {
    background: var(--accent-cyan);
    color: var(--void);
}

/* ============================================
   Navigation
   ============================================ */
.navbar {
    background: linear-gradient(to bottom, var(--deep), transparent);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-subtle);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--space-xl);
    height: 72px;
    display: flex;
    align-items: center;
    gap: var(--space-xl);
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 1.125rem;
    color: var(--text-bright);
    letter-spacing: -0.02em;
}

.nav-brand svg {
    color: var(--accent-cyan);
    opacity: 0.9;
}

.nav-links {
    display: flex;
    gap: var(--space-xs);
}

.nav-link {
    font-family: var(--font-display);
    font-size: 0.875rem;
    font-weight: 500;
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    transition: all 0.2s ease;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 4px;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--accent-cyan);
    transition: all 0.2s ease;
    transform: translateX(-50%);
    border-radius: 1px;
}

.nav-link:hover {
    color: var(--text-bright);
    background: var(--elevated);
}

.nav-link.active {
    color: var(--text-bright);
}

.nav-link.active::after {
    width: 20px;
}

.nav-search {
    margin-left: auto;
    position: relative;
}

.nav-search input {
    width: 260px;
    padding: var(--space-sm) var(--space-md);
    padding-left: 2.5rem;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    color: var(--text-primary);
    font-family: var(--font-display);
    font-size: 0.875rem;
    transition: all 0.2s ease;
}

.nav-search::before {
    content: '';
    position: absolute;
    left: 0.875rem;
    top: 50%;
    transform: translateY(-50%);
    width: 16px;
    height: 16px;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%235c6370'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0z'/%3E%3C/svg%3E");
    background-size: contain;
    pointer-events: none;
}

.nav-search input::placeholder {
    color: var(--text-muted);
}

.nav-search input:focus {
    outline: none;
    border-color: var(--accent-cyan);
    box-shadow: 0 0 0 3px var(--accent-cyan-dim);
    background: var(--elevated);
}

.search-dropdown {
    position: absolute;
    top: calc(100% + var(--space-sm));
    left: 0;
    right: 0;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: 0 20px 40px -12px rgba(0, 0, 0, 0.5);
    max-height: 420px;
    overflow-y: auto;
    display: none;
    animation: dropdownIn 0.2s ease;
}

@keyframes dropdownIn {
    from {
        opacity: 0;
        transform: translateY(-8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.search-dropdown.active {
    display: block;
}

.search-result {
    display: block;
    padding: var(--space-md);
    border-bottom: 1px solid var(--border-subtle);
    transition: background 0.15s ease;
}

.search-result:last-child {
    border-bottom: none;
}

.search-result:hover,
.search-result:focus {
    background: var(--elevated);
    outline: none;
}

.search-result-title {
    font-family: var(--font-display);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-bright);
    margin-bottom: var(--space-xs);
    line-height: 1.4;
}

.search-result-meta {
    font-family: var(--font-mono);
    font-size: 0.6875rem;
    color: var(--text-muted);
    letter-spacing: 0.02em;
}

/* ============================================
   Main Content
   ============================================ */
.main-content {
    flex: 1;
    padding: var(--space-2xl) 0 var(--space-3xl);
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--space-xl);
}

/* ============================================
   Page Header
   ============================================ */
.page-header {
    margin-bottom: var(--space-2xl);
    padding-bottom: var(--space-xl);
    border-bottom: 1px solid var(--border-subtle);
}

.page-header h1 {
    font-family: var(--font-display);
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    color: var(--text-bright);
    margin-bottom: var(--space-sm);
    line-height: 1.2;
}

.subtitle {
    font-family: var(--font-body);
    font-size: 1.125rem;
    color: var(--text-secondary);
    font-style: italic;
}

.stats {
    display: flex;
    gap: var(--space-xl);
    margin-top: var(--space-lg);
}

.stat {
    font-family: var(--font-mono);
    font-size: 0.8125rem;
    color: var(--text-muted);
    display: flex;
    align-items: baseline;
    gap: var(--space-xs);
}

.stat strong {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--accent-cyan);
}

/* Breadcrumb */
.breadcrumb {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-bottom: var(--space-md);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.breadcrumb a {
    color: var(--text-secondary);
    transition: color 0.15s ease;
}

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

.breadcrumb span:not(:last-child)::after {
    content: none;
}

/* ============================================
   Sections
   ============================================ */
.section {
    margin-bottom: var(--space-3xl);
}

.section-title {
    font-family: var(--font-display);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-lg);
    padding-bottom: var(--space-md);
    border-bottom: 1px solid var(--border-subtle);
}

.section-title svg {
    color: var(--accent-amber);
    width: 16px;
    height: 16px;
}

/* ============================================
   Paper Cards (Featured Grid)
   ============================================ */
.paper-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(380px, 1fr));
    gap: var(--space-lg);
}

.paper-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    transition: all 0.25s ease;
    position: relative;
    overflow: hidden;
}

.paper-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-cyan), var(--accent-emerald));
    opacity: 0;
    transition: opacity 0.25s ease;
}

.paper-card:hover {
    border-color: var(--border);
    background: var(--elevated);
    transform: translateY(-2px);
    box-shadow: 0 12px 32px -8px rgba(0, 0, 0, 0.4);
}

.paper-card:hover::before {
    opacity: 1;
}

.paper-card.featured {
    border-color: var(--accent-emerald);
    border-width: 1px;
}

.paper-card.featured::before {
    opacity: 1;
    background: var(--accent-emerald);
}

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

.paper-category {
    font-family: var(--font-mono);
    font-size: 0.6875rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.paper-category-badge {
    font-family: var(--font-mono);
    font-size: 0.6875rem;
    padding: var(--space-xs) var(--space-sm);
    background: var(--elevated);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.paper-score {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 600;
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
}

.score-high {
    background: var(--accent-emerald-dim);
    color: var(--accent-emerald);
}

.score-medium {
    background: var(--accent-amber-dim);
    color: var(--accent-amber);
}

.score-low {
    background: var(--elevated);
    color: var(--text-muted);
}

.paper-title {
    font-family: var(--font-display);
    font-size: 1.0625rem;
    font-weight: 600;
    line-height: 1.4;
    margin-bottom: var(--space-sm);
    letter-spacing: -0.01em;
}

.paper-title a {
    color: var(--text-bright);
    transition: color 0.15s ease;
}

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

.paper-summary {
    font-family: var(--font-body);
    font-size: 0.9375rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: var(--space-md);
}

.paper-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-xs);
    margin-bottom: var(--space-md);
}

.tag {
    font-family: var(--font-mono);
    font-size: 0.6875rem;
    padding: var(--space-xs) var(--space-sm);
    background: var(--elevated);
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    transition: all 0.15s ease;
}

.tag:hover {
    background: var(--border);
    color: var(--text-secondary);
}

.tag-secondary {
    background: transparent;
    border: 1px solid var(--border);
}

.tag-small {
    font-size: 0.625rem;
    padding: 2px 6px;
}

.paper-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--space-md);
    border-top: 1px solid var(--border-subtle);
}

.paper-date {
    font-family: var(--font-mono);
    font-size: 0.6875rem;
    color: var(--text-muted);
}

.paper-link {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--accent-cyan);
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    transition: all 0.15s ease;
}

.paper-link:hover {
    color: var(--text-bright);
}

/* ============================================
   Paper List
   ============================================ */
.paper-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.paper-item {
    display: flex;
    gap: var(--space-xl);
    padding: var(--space-lg);
    background: var(--surface);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    transition: all 0.2s ease;
}

.paper-item:hover {
    background: var(--elevated);
    border-color: var(--border);
}

.paper-item-main {
    flex: 1;
    min-width: 0;
}

.paper-item-header {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-sm);
}

.paper-tags-inline {
    display: flex;
    gap: var(--space-xs);
}

.paper-item-title {
    font-family: var(--font-display);
    font-size: 1rem;
    font-weight: 500;
    line-height: 1.4;
    margin-bottom: var(--space-xs);
}

.paper-item-title a {
    color: var(--text-bright);
}

.paper-item-title a:hover {
    color: var(--accent-cyan);
}

.paper-item-authors {
    font-family: var(--font-body);
    font-size: 0.8125rem;
    font-style: italic;
    color: var(--text-muted);
    margin-bottom: var(--space-sm);
}

.paper-item-summary {
    font-family: var(--font-body);
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.paper-contributions {
    margin-top: var(--space-sm);
    padding-left: var(--space-lg);
    font-family: var(--font-body);
    font-size: 0.8125rem;
    color: var(--text-muted);
}

.paper-contributions li {
    margin-bottom: var(--space-xs);
}

.paper-item-side {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: var(--space-sm);
    flex-shrink: 0;
    min-width: 100px;
}

.paper-actions {
    display: flex;
    gap: var(--space-xs);
}

/* ============================================
   Buttons
   ============================================ */
.btn {
    font-family: var(--font-display);
    font-size: 0.875rem;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-md);
    border: 1px solid transparent;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-primary {
    background: var(--accent-cyan);
    color: var(--void);
}

.btn-primary:hover {
    background: var(--text-bright);
    color: var(--void);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px var(--accent-cyan-dim);
}

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

.btn-outline:hover {
    background: var(--elevated);
    border-color: var(--text-muted);
    color: var(--text-bright);
}

.btn-small {
    font-family: var(--font-mono);
    font-size: 0.6875rem;
    font-weight: 500;
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
    background: var(--elevated);
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.btn-small:hover {
    background: var(--border);
    color: var(--text-bright);
}

/* ============================================
   Category Grid
   ============================================ */
.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--space-md);
}

.category-card {
    display: block;
    padding: var(--space-lg);
    background: var(--surface);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    transition: all 0.25s ease;
    position: relative;
    overflow: hidden;
}

.category-card::after {
    content: '→';
    position: absolute;
    right: var(--space-lg);
    top: 50%;
    transform: translateY(-50%) translateX(-8px);
    font-size: 1.25rem;
    color: var(--accent-cyan);
    opacity: 0;
    transition: all 0.25s ease;
}

.category-card:hover {
    background: var(--elevated);
    border-color: var(--accent-cyan);
    transform: translateX(4px);
}

.category-card:hover::after {
    opacity: 1;
    transform: translateY(-50%) translateX(0);
}

.category-card h3 {
    font-family: var(--font-display);
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-bright);
    margin-bottom: var(--space-xs);
}

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

/* ============================================
   Filter Bar
   ============================================ */
.filter-bar {
    display: flex;
    gap: var(--space-lg);
    padding: var(--space-md) var(--space-lg);
    background: var(--surface);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    margin-bottom: var(--space-xl);
}

.filter-group {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.filter-group label {
    font-family: var(--font-mono);
    font-size: 0.6875rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.filter-group select {
    font-family: var(--font-display);
    font-size: 0.8125rem;
    padding: var(--space-xs) var(--space-sm);
    background: var(--elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.15s ease;
}

.filter-group select:focus {
    outline: none;
    border-color: var(--accent-cyan);
}

/* ============================================
   Paper Detail
   ============================================ */
.paper-detail {
    max-width: 900px;
}

.paper-detail-header {
    margin-bottom: var(--space-2xl);
}

.paper-detail-meta {
    display: flex;
    gap: var(--space-sm);
    margin-bottom: var(--space-md);
}

.paper-detail-title {
    font-family: var(--font-display);
    font-size: 2rem;
    font-weight: 700;
    line-height: 1.3;
    letter-spacing: -0.02em;
    color: var(--text-bright);
    margin-bottom: var(--space-md);
}

.paper-detail-authors {
    font-family: var(--font-body);
    font-size: 1rem;
    font-style: italic;
    color: var(--text-secondary);
    margin-bottom: var(--space-md);
    line-height: 1.7;
}

.author {
    white-space: nowrap;
}

.paper-detail-info {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-md);
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-bottom: var(--space-lg);
}

.paper-detail-actions {
    display: flex;
    gap: var(--space-sm);
}

.paper-section {
    margin-bottom: var(--space-xl);
}

.paper-section h2 {
    font-family: var(--font-display);
    font-size: 0.6875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-muted);
    margin-bottom: var(--space-md);
    padding-bottom: var(--space-sm);
    border-bottom: 1px solid var(--border-subtle);
}

.summary-box {
    padding: var(--space-lg);
    background: var(--accent-emerald-dim);
    border-left: 3px solid var(--accent-emerald);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    font-family: var(--font-body);
    font-size: 1.0625rem;
    line-height: 1.7;
    color: var(--text-bright);
}

.abstract-box {
    padding: var(--space-lg);
    background: var(--surface);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    font-family: var(--font-body);
    font-size: 0.9375rem;
    line-height: 1.8;
    color: var(--text-secondary);
}

.contributions-list {
    padding-left: var(--space-lg);
    font-family: var(--font-body);
}

.contributions-list li {
    margin-bottom: var(--space-sm);
    line-height: 1.6;
    color: var(--text-primary);
}

.contributions-list li::marker {
    color: var(--accent-cyan);
}

.paper-detail-footer {
    margin-top: var(--space-2xl);
    padding-top: var(--space-lg);
    border-top: 1px solid var(--border-subtle);
}

.analysis-info {
    font-family: var(--font-mono);
    font-size: 0.6875rem;
    color: var(--text-muted);
    margin-bottom: var(--space-sm);
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.relevance-reason {
    font-family: var(--font-body);
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-style: italic;
}

/* ============================================
   Empty State
   ============================================ */
.empty-state {
    text-align: center;
    padding: var(--space-3xl) var(--space-xl);
    color: var(--text-muted);
    font-family: var(--font-body);
    font-style: italic;
}

/* ============================================
   Footer
   ============================================ */
.footer {
    border-top: 1px solid var(--border-subtle);
    padding: var(--space-lg) 0;
    margin-top: auto;
    background: var(--deep);
}

.footer-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--space-xl);
    text-align: center;
}

.footer p {
    font-family: var(--font-mono);
    font-size: 0.6875rem;
    color: var(--text-muted);
    letter-spacing: 0.02em;
}

/* ============================================
   Animations
   ============================================ */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(12px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.paper-card,
.paper-item,
.category-card {
    animation: fadeInUp 0.4s ease backwards;
}

.paper-card:nth-child(1), .paper-item:nth-child(1), .category-card:nth-child(1) { animation-delay: 0.05s; }
.paper-card:nth-child(2), .paper-item:nth-child(2), .category-card:nth-child(2) { animation-delay: 0.1s; }
.paper-card:nth-child(3), .paper-item:nth-child(3), .category-card:nth-child(3) { animation-delay: 0.15s; }
.paper-card:nth-child(4), .paper-item:nth-child(4) { animation-delay: 0.2s; }
.paper-card:nth-child(5), .paper-item:nth-child(5) { animation-delay: 0.25s; }
.paper-card:nth-child(6), .paper-item:nth-child(6) { animation-delay: 0.3s; }
.paper-card:nth-child(7), .paper-item:nth-child(7) { animation-delay: 0.35s; }
.paper-card:nth-child(8), .paper-item:nth-child(8) { animation-delay: 0.4s; }

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 900px) {
    .nav-container {
        flex-wrap: wrap;
        height: auto;
        padding: var(--space-md);
        gap: var(--space-md);
    }

    .nav-links {
        order: 3;
        width: 100%;
        overflow-x: auto;
        padding-bottom: var(--space-xs);
        -webkit-overflow-scrolling: touch;
    }

    .nav-search {
        width: 100%;
        order: 2;
    }

    .nav-search input {
        width: 100%;
    }

    .page-header h1 {
        font-size: 1.75rem;
    }

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

    .paper-item {
        flex-direction: column;
        gap: var(--space-md);
    }

    .paper-item-side {
        flex-direction: row;
        justify-content: space-between;
        align-items: center;
        width: 100%;
    }

    .filter-bar {
        flex-direction: column;
        gap: var(--space-sm);
    }

    .paper-detail-title {
        font-size: 1.5rem;
    }

    .paper-detail-actions {
        flex-direction: column;
    }

    .paper-detail-actions .btn {
        width: 100%;
        justify-content: center;
    }

    .stats {
        flex-direction: column;
        gap: var(--space-sm);
    }
}

/* Scrollbar styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--deep);
}

::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}