/* Last Week in Health AI - Paper-Feed-First Design */
/* Light theme default with dark mode toggle */

/* =============================================================================
   CSS Variables - Light Theme (Default)
============================================================================= */
:root, .theme-light {
    /* Clinical Green Color Palette */
    --primary: #059669;
    --primary-dark: #047857;
    --primary-light: #10B981;
    --primary-bg: rgba(5, 150, 105, 0.08);

    /* Light Theme Colors */
    --bg-body: #F8FAFC;
    --bg-card: #FFFFFF;
    --bg-hover: #F1F5F9;
    --border: #E2E8F0;
    --border-light: #F1F5F9;

    /* Text */
    --text-primary: #0F172A;
    --text-secondary: #475569;
    --text-muted: #94A3B8;

    /* Journal Badge Colors */
    --badge-nejm: #DC2626;
    --badge-jama: #2563EB;
    --badge-lancet: #7C3AED;
    --badge-nature: #0891B2;
    --badge-bmj: #EA580C;
    --badge-preprint: #6B7280;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);

    /* Typography */
    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;

    /* Spacing */
    --container-width: 1500px;
    --radius: 12px;
    --radius-sm: 8px;
}

/* =============================================================================
   Dark Theme
============================================================================= */
.theme-dark {
    --bg-body: #0F172A;
    --bg-card: #1E293B;
    --bg-hover: #334155;
    --border: #334155;
    --border-light: #1E293B;

    --text-primary: #F8FAFC;
    --text-secondary: #94A3B8;
    --text-muted: #64748B;

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-body);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* =============================================================================
   Header
============================================================================= */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-sm);
}

.theme-dark .header {
    background: rgba(30, 41, 59, 0.95);
    backdrop-filter: blur(10px);
}

.header-content {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 14px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--text-primary);
}

.logo-icon {
    font-size: 26px;
}

.logo-text {
    font-size: 17px;
    font-weight: 600;
    color: var(--text-primary);
}

.nav {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 8px;
    border-radius: var(--radius-sm);
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.nav-btn:hover {
    color: var(--primary);
    background: var(--primary-bg);
}

/* Theme toggle icons */
.theme-light .icon-moon { display: none; }
.theme-dark .icon-sun { display: none; }
.theme-light .icon-sun { display: block; }
.theme-dark .icon-moon { display: block; }

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    transition: all 0.2s;
}

.nav-link:hover {
    color: var(--primary);
    background: var(--primary-bg);
}

/* =============================================================================
   Main Layout
============================================================================= */
.main {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* =============================================================================
   Hero Section
============================================================================= */
.hero {
    text-align: center;
    padding: 48px 0 32px;
}

.hero-title {
    font-size: 32px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
    letter-spacing: -0.5px;
}

.hero-subtitle {
    font-size: 16px;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.hero-stats {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 24px;
    flex-wrap: wrap;
}

.stat-item {
    display: flex;
    align-items: baseline;
    gap: 6px;
}

.stat-number {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary);
}

.stat-label {
    font-size: 14px;
    color: var(--text-muted);
}

.stat-divider {
    width: 1px;
    height: 24px;
    background: var(--border);
}

/* =============================================================================
   Filters & Tabs Section
============================================================================= */
.filters-section {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 0;
    margin-bottom: 24px;
    border-bottom: 1px solid var(--border);
    flex-wrap: wrap;
    gap: 16px;
}

.tabs {
    display: flex;
    gap: 4px;
    background: var(--bg-hover);
    padding: 4px;
    border-radius: var(--radius-sm);
}

.tab-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    border-radius: 6px;
    transition: all 0.2s;
}

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

.tab-btn.active {
    background: var(--bg-card);
    color: var(--primary);
    box-shadow: var(--shadow-sm);
}

.tab-count {
    font-size: 12px;
    padding: 2px 8px;
    background: var(--primary-bg);
    color: var(--primary);
    border-radius: 12px;
    font-weight: 600;
}

.filter-controls {
    display: flex;
    align-items: center;
    gap: 12px;
}

.filter-select {
    padding: 8px 32px 8px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--bg-card);
    color: var(--text-primary);
    font-size: 14px;
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%2394A3B8' stroke-width='2'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 10px center;
}

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

/* Searchable Journal Dropdown */
.filter-dropdown {
    position: relative;
}

.filter-dropdown-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--bg-card);
    color: var(--text-primary);
    font-size: 14px;
    cursor: pointer;
    min-width: 160px;
    justify-content: space-between;
}

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

.filter-dropdown-menu {
    display: none;
    position: absolute;
    top: calc(100% + 4px);
    left: 0;
    min-width: 280px;
    max-height: 400px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-md);
    z-index: 50;
    overflow: hidden;
}

.filter-dropdown.open .filter-dropdown-menu {
    display: block;
}

.filter-search {
    width: 100%;
    padding: 12px;
    border: none;
    border-bottom: 1px solid var(--border);
    background: var(--bg-hover);
    color: var(--text-primary);
    font-size: 14px;
}

.filter-search:focus {
    outline: none;
    background: var(--bg-card);
}

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

.filter-options {
    max-height: 320px;
    overflow-y: auto;
}

.filter-option {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 12px;
    cursor: pointer;
    transition: background 0.15s;
    font-size: 13px;
    color: var(--text-primary);
}

.filter-option:hover {
    background: var(--bg-hover);
}

.filter-option.selected {
    background: var(--primary-bg);
    color: var(--primary);
}

.filter-option-count {
    font-size: 12px;
    color: var(--text-muted);
    background: var(--bg-hover);
    padding: 2px 6px;
    border-radius: 4px;
}

.filter-option.selected .filter-option-count {
    background: var(--primary);
    color: white;
}

.calendar-toggle-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-secondary);
    font-size: 14px;
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: all 0.2s;
}

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

/* =============================================================================
   Content Layout (Two Column)
============================================================================= */
.content-layout {
    display: flex;
    gap: 24px;
    align-items: flex-start;
}

/* =============================================================================
   Papers Section (Primary)
============================================================================= */
.papers-section {
    flex: 1;
    min-width: 0;
    margin-bottom: 48px;
}

.papers-list {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 14px;
}

/* 3 columns on large screens */
@media (max-width: 1600px) {
    .papers-list {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* 2 columns on medium screens */
@media (max-width: 1200px) {
    .papers-list {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Single column on smaller screens */
@media (max-width: 768px) {
    .papers-list {
        grid-template-columns: 1fr;
    }
}

.loading-state, .empty-state {
    text-align: center;
    color: var(--text-muted);
    padding: 60px 20px;
    font-size: 15px;
}

/* =============================================================================
   Paper Card - Compact Grid Layout with Journal Logo
============================================================================= */
.paper-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px;
    transition: all 0.2s;
    box-shadow: var(--shadow-sm);
    display: flex;
    flex-direction: column;
    height: 100%;
}

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

/* Paper Header with Logo and Badge */
.paper-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
}

.journal-logo-container {
    width: 36px;
    height: 36px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.journal-logo {
    max-width: 36px;
    max-height: 36px;
    border-radius: 6px;
    object-fit: contain;
    background: white;
    padding: 2px;
}

.journal-logo-fallback {
    width: 36px;
    height: 36px;
    border-radius: 6px;
    background: linear-gradient(135deg, var(--primary-bg) 0%, var(--bg-hover) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    font-weight: 700;
    color: var(--primary);
    border: 1px solid var(--border-light);
}

.paper-header-info {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.paper-header-info .paper-badge {
    font-size: 10px;
}

.paper-header-info .paper-date {
    font-size: 11px;
    color: var(--text-muted);
}

/* Legacy placeholder class (keep for backwards compat) */
.journal-logo-placeholder {
    width: 28px;
    height: 28px;
    border-radius: 4px;
    background: var(--bg-hover);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: 700;
    color: var(--text-muted);
    flex-shrink: 0;
}

/* Journal Badge */
.paper-badge {
    display: inline-flex;
    align-items: center;
    padding: 3px 8px;
    border-radius: 4px;
    font-size: 10px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.3px;
}

.paper-badge.nejm { background: rgba(220, 38, 38, 0.1); color: var(--badge-nejm); }
.paper-badge.jama { background: rgba(37, 99, 235, 0.1); color: var(--badge-jama); }
.paper-badge.lancet { background: rgba(124, 58, 237, 0.1); color: var(--badge-lancet); }
.paper-badge.nature { background: rgba(8, 145, 178, 0.1); color: var(--badge-nature); }
.paper-badge.bmj { background: rgba(234, 88, 12, 0.1); color: var(--badge-bmj); }
.paper-badge.preprint { background: rgba(107, 114, 128, 0.1); color: var(--badge-preprint); }
.paper-badge.default { background: var(--primary-bg); color: var(--primary); }

.paper-title {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    line-height: 1.4;
    margin-bottom: 6px;
    /* Limit title to 2 lines in grid view */
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.paper-meta {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 12px;
    font-size: 11px;
    color: var(--text-muted);
}

.paper-date {
    color: var(--text-muted);
}

/* =============================================================================
   6-QUESTION AI SUMMARY FRAMEWORK - Compact & Aesthetic Design
============================================================================= */

.summary-framework {
    margin: 10px 0;
    display: flex;
    flex-direction: column;
    gap: 8px;
    flex: 1;
}

/* Individual Summary Section - Compact */
.summary-section {
    background: transparent;
    border-radius: var(--radius-sm);
    padding: 8px 10px;
    border-left: 3px solid var(--border-light);
}

.summary-section.empty {
    display: none;
}

/* Section Label - Question Title */
.summary-section-label {
    display: flex;
    align-items: flex-start;
    gap: 6px;
    font-size: 11px;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 4px;
    line-height: 1.3;
    text-transform: uppercase;
    letter-spacing: 0.3px;
}

/* Question Type Tag */
.question-type {
    font-size: 9px;
    font-weight: 500;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.3px;
    opacity: 0.8;
}

/* Section Content - Concise */
.summary-section-content {
    font-size: 12px;
    color: var(--text-secondary);
    line-height: 1.5;
    /* Limit to 3 lines */
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.summary-section-content ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.summary-section-content li {
    padding-left: 12px;
    position: relative;
    margin-bottom: 3px;
    /* Limit each item */
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.summary-section-content li::before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--primary);
    font-size: 10px;
}

.summary-section-content li:last-child {
    margin-bottom: 0;
}

.no-data {
    font-style: italic;
    color: var(--text-muted);
    font-size: 11px;
}

/* Label Hint (parenthetical info) */
.label-hint {
    font-weight: 400;
    font-size: 9px;
    color: var(--text-muted);
    text-transform: none;
    letter-spacing: 0;
}

/* Question 1: Main Research Question - Prominent */
.summary-section.question {
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.08) 0%, rgba(139, 92, 246, 0.03) 100%);
    border-left: 3px solid #8b5cf6;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    padding: 10px 12px;
}

.summary-section.question .summary-section-label {
    color: #8b5cf6;
    font-size: 10px;
    font-weight: 700;
    text-transform: none;
    letter-spacing: 0;
}

.summary-section.question .summary-section-content {
    font-size: 13px;
    color: var(--text-primary);
    font-weight: 500;
    line-height: 1.4;
    /* Limit to 3 lines */
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* Legacy class name support */
.summary-question {
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.08) 0%, rgba(16, 185, 129, 0.03) 100%);
    border-left: 3px solid var(--primary);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    padding: 10px 12px;
}

.summary-question .summary-section-label {
    color: var(--primary);
    font-size: 11px;
    font-weight: 700;
}

.summary-question .summary-section-content {
    font-size: 13px;
    color: var(--text-primary);
    font-weight: 500;
    line-height: 1.4;
    /* Limit to 3 lines */
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* Color-coded sections */
.summary-section.findings { border-left-color: #3b82f6; }
.summary-section.findings .summary-section-label { color: #3b82f6; }

.summary-section.methods { border-left-color: #8b5cf6; }
.summary-section.methods .summary-section-label { color: #8b5cf6; }

.summary-section.impact { border-left-color: #f59e0b; }
.summary-section.impact .summary-section-label { color: #f59e0b; }

.summary-section.limitations { border-left-color: #ef4444; }
.summary-section.limitations .summary-section-label { color: #ef4444; }

.summary-section.contribution { border-left-color: #10b981; }
.summary-section.contribution .summary-section-label { color: #10b981; }

/* Expand/Collapse Toggle Button - Compact */
.summary-expand-toggle {
    display: flex;
    align-items: center;
    gap: 6px;
    background: var(--bg-hover);
    border: none;
    border-radius: var(--radius-sm);
    padding: 6px 12px;
    cursor: pointer;
    font-size: 11px;
    font-weight: 500;
    color: var(--text-muted);
    transition: all 0.2s ease;
    width: 100%;
    justify-content: center;
}

.summary-expand-toggle:hover {
    background: var(--primary-bg);
    color: var(--primary);
}

.summary-expand-toggle .chevron-icon {
    transition: transform 0.3s ease;
    width: 12px;
    height: 12px;
}

.summary-expand-toggle.expanded .chevron-icon {
    transform: rotate(180deg);
}

.summary-expand-toggle .toggle-hint {
    font-weight: 400;
    font-size: 10px;
}

/* Collapsible Details Section */
.summary-details {
    display: flex;
    flex-direction: column;
    gap: 16px;
    overflow: hidden;
    transition: all 0.3s ease;
    max-height: 2000px;
    opacity: 1;
}

.summary-details.collapsed {
    max-height: 0;
    opacity: 0;
    margin: 0;
    padding: 0;
}

/* 2x2 Grid for Questions 2-5 */
.summary-grid-2x2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

/* Question 6: Contribution (Full Width, Highlighted) */
.summary-contribution {
    background: linear-gradient(135deg, var(--bg-hover) 0%, var(--primary-bg) 100%);
    border: 1px solid var(--primary);
    border-left: 4px solid var(--primary);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.summary-contribution .summary-section-label {
    color: var(--primary);
}

/* Legacy styles (keep for backwards compatibility) */
.research-question {
    background: var(--primary-bg);
    border-left: 3px solid var(--primary);
    padding: 12px 16px;
    margin-bottom: 20px;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.research-question-label {
    font-size: 11px;
    font-weight: 600;
    color: var(--primary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 4px;
}

.research-question-text {
    font-size: 15px;
    color: var(--text-primary);
    font-style: italic;
}

.summary-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 16px;
}

.summary-box {
    padding: 12px;
    background: var(--bg-hover);
    border-radius: var(--radius-sm);
}

.summary-box-label {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 11px;
    font-weight: 600;
    color: var(--primary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 8px;
}

.summary-box-label.muted {
    color: var(--text-muted);
}

.summary-box ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.summary-box li {
    font-size: 13px;
    color: var(--text-secondary);
    line-height: 1.5;
    padding-left: 14px;
    position: relative;
    margin-bottom: 4px;
}

.summary-box li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 7px;
    width: 4px;
    height: 4px;
    background: var(--primary);
    border-radius: 50%;
}

.summary-box li:last-child {
    margin-bottom: 0;
}

/* Paper Actions */
.paper-actions {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-top: auto;
    padding-top: 12px;
    border-top: 1px solid var(--border-light);
}

.paper-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: var(--primary);
    text-decoration: none;
    font-size: 13px;
    font-weight: 500;
    padding: 8px 14px;
    background: var(--primary-bg);
    border-radius: var(--radius-sm);
    transition: all 0.2s;
}

.paper-link:hover {
    background: var(--primary);
    color: white;
}

/* Abstract Collapsible */
.abstract-toggle {
    display: flex;
    align-items: center;
    gap: 6px;
    color: var(--text-secondary);
    font-size: 13px;
    cursor: pointer;
    padding: 8px 0;
    border: none;
    background: none;
    transition: color 0.2s;
}

.abstract-toggle:hover {
    color: var(--text-primary);
}

.abstract-toggle svg {
    transition: transform 0.2s;
}

.abstract-toggle.open svg {
    transform: rotate(90deg);
}

.abstract-content {
    display: none;
    padding: 16px;
    margin-top: 12px;
    background: var(--bg-hover);
    border-radius: var(--radius-sm);
    font-size: 14px;
    line-height: 1.7;
    color: var(--text-secondary);
}

.abstract-content.show {
    display: block;
}

/* =============================================================================
   Sidebar (Collapsed Calendar)
============================================================================= */
.sidebar {
    width: 280px;
    flex-shrink: 0;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    position: sticky;
    top: 80px;
    transition: all 0.3s;
}

.sidebar.collapsed {
    display: none;
}

.sidebar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px;
    border-bottom: 1px solid var(--border);
}

.sidebar-header h3 {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
}

.sidebar-close {
    background: transparent;
    border: none;
    color: var(--text-muted);
    font-size: 20px;
    cursor: pointer;
    padding: 4px;
}

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

.calendar-container {
    padding: 16px;
}

.calendar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}

.calendar-title {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
}

.calendar-nav {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    cursor: pointer;
    padding: 6px;
    border-radius: 6px;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.calendar-nav:hover {
    color: var(--primary);
    border-color: var(--primary);
}

.calendar-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 4px;
}

.calendar-day-header {
    text-align: center;
    font-size: 10px;
    font-weight: 600;
    color: var(--text-muted);
    padding: 6px 0;
}

.calendar-day {
    aspect-ratio: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    border-radius: 6px;
    background: var(--bg-hover);
    cursor: pointer;
    transition: all 0.2s;
    font-size: 12px;
}

.calendar-day:hover {
    background: var(--primary-bg);
}

.calendar-day.empty {
    background: transparent;
    cursor: default;
}

.calendar-day.today {
    border: 2px solid var(--primary);
}

.calendar-day.selected {
    background: var(--primary);
    color: white;
}

.calendar-day.has-papers {
    background: var(--primary-bg);
    font-weight: 600;
}

.day-number {
    font-size: 12px;
}

.day-count {
    font-size: 9px;
    color: var(--primary);
    font-weight: 600;
}

.calendar-day.selected .day-count {
    color: rgba(255, 255, 255, 0.9);
}

/* =============================================================================
   Search Modal
============================================================================= */
.search-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.6);
    z-index: 200;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding: 100px 20px;
}

.theme-dark .search-modal {
    background: rgba(0, 0, 0, 0.8);
}

.search-modal.hidden {
    display: none;
}

.search-modal-content {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    width: 100%;
    max-width: 600px;
    max-height: 70vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-md);
}

.search-header {
    display: flex;
    align-items: center;
    padding: 16px;
    border-bottom: 1px solid var(--border);
    gap: 12px;
}

.search-header input {
    flex: 1;
    background: var(--bg-hover);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 12px 16px;
    color: var(--text-primary);
    font-size: 15px;
    font-family: inherit;
}

.search-header input:focus {
    outline: none;
    border-color: var(--primary);
}

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

.search-close {
    background: transparent;
    border: none;
    color: var(--text-muted);
    font-size: 24px;
    cursor: pointer;
    padding: 4px 8px;
}

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

.search-results {
    overflow-y: auto;
    padding: 16px;
    flex: 1;
}

.search-result-item {
    padding: 12px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: background 0.2s;
    margin-bottom: 8px;
}

.search-result-item:hover {
    background: var(--bg-hover);
}

.search-result-title {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.search-result-meta {
    font-size: 12px;
    color: var(--text-muted);
}

.search-no-results {
    text-align: center;
    color: var(--text-muted);
    padding: 40px;
}

/* =============================================================================
   Footer
============================================================================= */
.footer {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 32px 24px;
    text-align: center;
    color: var(--text-muted);
    font-size: 13px;
    border-top: 1px solid var(--border);
}

/* =============================================================================
   Responsive Design
============================================================================= */
@media (max-width: 768px) {
    .header-content {
        padding: 12px 16px;
    }

    .logo-text {
        font-size: 15px;
    }

    .main {
        padding: 0 16px;
    }

    .hero {
        padding: 32px 0 24px;
    }

    .hero-title {
        font-size: 24px;
    }

    .hero-subtitle {
        font-size: 14px;
    }

    .hero-stats {
        gap: 16px;
    }

    .stat-number {
        font-size: 20px;
    }

    .filters-section {
        flex-direction: column;
        align-items: stretch;
    }

    .tabs {
        justify-content: center;
    }

    .filter-controls {
        justify-content: center;
    }

    .content-layout {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        position: fixed;
        top: auto;
        bottom: 0;
        left: 0;
        right: 0;
        border-radius: var(--radius) var(--radius) 0 0;
        max-height: 60vh;
        z-index: 150;
    }

    .sidebar.collapsed {
        display: none;
    }

    .paper-card {
        padding: 16px;
    }

    .paper-title {
        font-size: 16px;
    }

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

    .summary-grid-2x2 {
        grid-template-columns: 1fr;
    }

    .summary-section {
        padding: 12px;
    }

    .summary-section-label {
        font-size: 12px;
    }
}

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

.paper-card {
    animation: fadeIn 0.3s ease-out;
}