/* ============================================
   Search with SEM - Premium Modern Stylesheet
   Google-inspired, Clean, Sophisticated Design
   ============================================ */

:root {
    /* Primary Brand Color */
    --primary: #4285f4;
    --primary-light: #75a0fc;
    --primary-dark: #3367d6;
    --primary-bg: #e8f0fe;
    --primary-text: #1a73e8;
    
    /* Semantic Colors */
    --success: #34a853;
    --warning: #fbbc05;
    --error: #ea4335;
    --info: #4285f4;
    
    /* Neutral Colors */
    --white: #ffffff;
    --black: #000000;
    --gray-50: #f8f9fa;
    --gray-100: #f1f3f4;
    --gray-200: #e8eaed;
    --gray-300: #d2d7d9;
    --gray-400: #b8bfc2;
    --gray-500: #9aa0a6;
    --gray-600: #70757a;
    --gray-700: #5f6368;
    --gray-800: #3c4043;
    --gray-900: #202124;
    
    /* Backgrounds */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #f1f3f4;
    --bg-elevated: #ffffff;
    --bg-overlay: rgba(0, 0, 0, 0.5);
    --bg-overlay-light: rgba(255, 255, 255, 0.95);
    
    /* Surface Colors */
    --card-bg: #ffffff;
    --card-border: #e0e0e0;
    --card-hover: #f5f5f5;
    --card-active: #e8eaed;
    
    /* Shadows - Google Material Design */
    --shadow-xs: 0 1px 2px 0 rgba(60, 64, 67, 0.1);
    --shadow-sm: 0 1px 3px 0 rgba(60, 64, 67, 0.30);
    --shadow-md: 0 2px 6px 2px rgba(60, 64, 67, 0.30);
    --shadow-lg: 0 4px 12px 4px rgba(60, 64, 67, 0.30);
    --shadow-xl: 0 8px 16px 8px rgba(60, 64, 67, 0.30);
    --shadow-2xl: 0 16px 32px 16px rgba(60, 64, 67, 0.30);
    
    /* Border Radius - Modern rounded corners */
    --radius-xs: 4px;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --radius-2xl: 24px;
    --radius-full: 9999px;
    --radius-pill: 20px;
    
    /* Spacing */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 12px;
    --space-lg: 16px;
    --space-xl: 20px;
    --space-2xl: 24px;
    --space-3xl: 32px;
    --space-4xl: 40px;
    --space-5xl: 48px;
    
    /* Typography */
    --font-family: 'Google Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'SF Mono', 'Roboto Mono', 'Courier New', monospace;
    
    --text-xs: 12px;
    --text-sm: 14px;
    --text-base: 16px;
    --text-lg: 18px;
    --text-xl: 20px;
    --text-2xl: 22px;
    --text-3xl: 24px;
    --text-4xl: 28px;
    --text-5xl: 32px;
    --text-6xl: 36px;
    
    --font-weight-light: 300;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    
    --line-height-tight: 1.25;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.75;
    
    /* Transitions */
    --transition-fast: 100ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 200ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-spring: 300ms cubic-bezier(0.175, 0.885, 0.32, 1.275);
    
    /* Z-Index */
    --z-base: 1;
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-fixed: 300;
    --z-modal: 400;
    --z-toast: 500;
    --z-loading: 1000;
    
    /* Header */
    --header-height: 64px;
    --header-height-mobile: 100px;
    
    /* Footer */
    --footer-height: 56px;
    --footer-height-mobile: 64px;
    
    /* Gamification */
    --streak-gold: #ffd700;
    --achievement-bg: #f8f9fa;
}

/* Dark Theme */
[data-theme="dark"] {
    --bg-primary: #202124;
    --bg-secondary: #303134;
    --bg-tertiary: #3c4043;
    --bg-elevated: #303134;
    --bg-overlay: rgba(0, 0, 0, 0.7);
    --bg-overlay-light: rgba(32, 33, 36, 0.95);
    
    --card-bg: #303134;
    --card-border: #5f6368;
    --card-hover: #3c4043;
    --card-active: #484a4d;
    
    --text-primary: #e8eaed;
    --text-secondary: #b8bfc2;
    --text-tertiary: #8d9196;
    
    --gray-50: #303134;
    --gray-100: #3c4043;
    --gray-200: #484a4d;
    --gray-300: #5f6368;
    --gray-400: #70757a;
    --gray-500: #8d9196;
    --gray-600: #9aa0a6;
    --gray-700: #b8bfc2;
    --gray-800: #d2d7d9;
    --gray-900: #e8eaed;
    
    --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.2);
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.4);
    --shadow-md: 0 2px 6px 2px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 4px 12px 4px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 8px 16px 8px rgba(0, 0, 0, 0.5);
    --shadow-2xl: 0 16px 32px 16px rgba(0, 0, 0, 0.6);
    
    --achievement-bg: #303134;
}

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

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

body {
    font-family: var(--font-family);
    font-size: var(--text-base);
    line-height: var(--line-height-normal);
    color: var(--gray-900);
    background: var(--bg-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: background var(--transition-normal), color var(--transition-normal);
    overflow-x: hidden;
}

[data-theme="dark"] body {
    color: var(--gray-100);
}

/* Selection */
::selection {
    background: var(--primary);
    color: var(--white);
}

/* Focus */
:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

button:focus-visible,
input:focus-visible,
textarea:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

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

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--gray-400);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--gray-500);
}

/* Safe Area */
@media (display-mode: standalone) {
    body {
        padding-bottom: calc(var(--footer-height-mobile) + env(safe-area-inset-bottom));
    }
}

/* ============================================
   Loading
   ============================================ */
.loading {
    display: none;
    position: fixed;
    inset: 0;
    background: var(--bg-primary);
    z-index: var(--z-loading);
    align-items: center;
    justify-content: center;
}

.loading.active {
    display: flex;
}

.loading .spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--gray-300);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

.loading .loading-text {
    margin-top: var(--space-lg);
    font-size: var(--text-sm);
    color: var(--gray-600);
    font-weight: var(--font-weight-medium);
}

/* ============================================
   Header - Google-inspired
   ============================================ */
header {
    position: sticky;
    top: 0;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--gray-200);
    padding: var(--space-md) var(--space-lg);
    z-index: var(--z-sticky);
    transition: box-shadow var(--transition-normal);
}

header.scrolled {
    box-shadow: var(--shadow-sm);
}

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

.logo {
    font-size: var(--text-2xl);
    font-weight: var(--font-weight-bold);
    display: flex;
    gap: 1px;
    cursor: pointer;
    user-select: none;
    color: var(--gray-900);
}

[data-theme="dark"] .logo {
    color: var(--gray-100);
}

.logo span {
    transition: transform var(--transition-spring);
}

.logo:hover span {
    transform: scale(1.05);
}

.logo span.c1 { color: var(--primary); }
.logo span.c2 { color: var(--error); }
.logo span.c3 { color: var(--success); }
.logo span.c4 { color: var(--warning); }
.logo span.c5 { color: #9c27b0; }
.logo span.c6 { color: var(--primary); }

.header-status {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.online-indicator {
    font-size: var(--text-xs);
    color: var(--success);
    display: flex;
    align-items: center;
    gap: 2px;
    font-weight: var(--font-weight-medium);
}

.online-indicator.offline {
    color: var(--error);
}

/* Auto-Save Toggle - Google-style */
.auto-save-indicator {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-xs) var(--space-sm);
    background: var(--bg-secondary);
    border-radius: var(--radius-pill);
    font-size: var(--text-sm);
    font-weight: var(--font-weight-medium);
    color: var(--gray-700);
    cursor: pointer;
    transition: all var(--transition-fast);
    border: 1px solid transparent;
}

.auto-save-indicator:hover {
    background: var(--gray-100);
    border-color: var(--gray-300);
}

.auto-save-indicator.on {
    background: var(--primary-bg);
    color: var(--primary);
    border-color: var(--primary-light);
}

.auto-save-indicator .toggle-text {
    transition: color var(--transition-fast);
}

.auto-save-indicator.on .toggle-text {
    color: var(--primary);
}

.auto-save-indicator .toggle-switch {
    width: 32px;
    height: 18px;
    background: var(--gray-400);
    border-radius: var(--radius-full);
    position: relative;
    transition: background var(--transition-fast);
}

.auto-save-indicator.on .toggle-switch {
    background: var(--primary);
}

.auto-save-indicator .toggle-switch::after {
    content: '';
    position: absolute;
    top: 1px;
    left: 1px;
    width: 16px;
    height: 16px;
    background: white;
    border-radius: 50%;
    transition: transform var(--transition-fast);
    box-shadow: 0 1px 2px rgba(0,0,0,0.2);
}

.auto-save-indicator.on .toggle-switch::after {
    transform: translateX(14px);
}

/* Search Bar - Google-style */
.search-wrap {
    position: relative;
    display: flex;
    align-items: center;
}

.search-box {
    flex: 1;
    padding: var(--space-sm) var(--space-md);
    padding-right: 84px;
    background: var(--bg-secondary);
    border: 1px solid var(--gray-300);
    border-radius: var(--radius-pill);
    font-size: var(--text-base);
    color: var(--gray-900);
    transition: all var(--transition-fast);
    font-family: inherit;
}

[data-theme="dark"] .search-box {
    background: var(--gray-800);
    border-color: var(--gray-600);
    color: var(--gray-100);
}

.search-box:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-bg);
    outline: none;
}

.search-box::placeholder {
    color: var(--gray-500);
}

.search-actions {
    display: flex;
    gap: var(--space-xs);
    position: absolute;
    right: var(--space-sm);
}

.icon-btn {
    width: 36px;
    height: 36px;
    border: none;
    background: var(--primary);
    color: white;
    border-radius: var(--radius-full);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    font-size: var(--text-sm);
    box-shadow: var(--shadow-xs);
}

.icon-btn:hover {
    background: var(--primary-dark);
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

.icon-btn:active {
    transform: scale(0.95);
}

.icon-btn i {
    pointer-events: none;
}

/* ============================================
   Main Content
   ============================================ */
main {
    flex: 1;
    padding: var(--space-lg);
    padding-bottom: calc(var(--footer-height-mobile) + var(--space-xl));
    overflow-y: auto;
}

/* ============================================
   Home View - Clean & Modern
   ============================================ */
.home {
    display: none;
    flex-direction: column;
    align-items: center;
    animation: fadeIn 0.3s ease;
}

.home.active {
    display: flex;
}

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

.home-logo {
    font-size: var(--text-5xl);
    font-weight: var(--font-weight-bold);
    margin-bottom: var(--space-xs);
    display: flex;
    gap: 2px;
    justify-content: center;
}

.home-logo span {
    transition: transform var(--transition-spring);
}

.home-logo:hover span {
    transform: scale(1.1);
}

.home-logo span.c1 { color: var(--primary); }
.home-logo span.c2 { color: var(--error); }
.home-logo span.c3 { color: var(--success); }
.home-logo span.c4 { color: var(--warning); }
.home-logo span.c5 { color: #9c27b0; }
.home-logo span.c6 { color: var(--primary); }

.home-sub {
    font-size: var(--text-xl);
    font-weight: var(--font-weight-semibold);
    color: var(--gray-800);
    margin-bottom: var(--space-xs);
}

[data-theme="dark"] .home-sub {
    color: var(--gray-200);
}

.home-tagline {
    font-size: var(--text-sm);
    color: var(--gray-600);
    margin-bottom: var(--space-xl);
}

[data-theme="dark"] .home-tagline {
    color: var(--gray-400);
}

/* Stats Section - Subtle like Google */
.stats-section {
    width: 100%;
    display: flex;
    justify-content: center;
    gap: var(--space-xl);
    margin-bottom: var(--space-3xl);
    padding: var(--space-md);
}

.stat-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-sm) var(--space-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    border-radius: var(--radius-md);
    background: transparent;
}

.stat-card:hover {
    background: var(--bg-secondary);
}

.stat-value {
    font-size: var(--text-xl);
    font-weight: var(--font-weight-bold);
    color: var(--gray-900);
    position: relative;
}

[data-theme="dark"] .stat-value {
    color: var(--gray-100);
}

.streak-indicator .fire-icon {
    position: absolute;
    top: -4px;
    right: -16px;
    font-size: var(--text-sm);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.2); }
}

.stat-label {
    font-size: var(--text-xs);
    color: var(--gray-600);
    font-weight: var(--font-weight-medium);
}

[data-theme="dark"] .stat-label {
    color: var(--gray-400);
}

/* Library Section */
.library-section {
    width: 100%;
    margin-bottom: var(--space-3xl);
}

.section-label {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: var(--text-lg);
    font-weight: var(--font-weight-semibold);
    color: var(--gray-900);
    margin-bottom: var(--space-lg);
}

[data-theme="dark"] .section-label {
    color: var(--gray-100);
}

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

.library-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: var(--space-lg);
}

.library-card {
    display: flex;
    flex-direction: column;
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    cursor: pointer;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-xs);
}

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

.library-card:active {
    transform: translateY(0);
}

.library-card img {
    width: 100%;
    height: 120px;
    object-fit: cover;
    background: var(--gray-100);
}

[data-theme="dark"] .library-card img {
    background: var(--gray-800);
}

.library-card-info {
    padding: var(--space-sm);
    flex: 1;
}

.library-card-title {
    font-size: var(--text-sm);
    font-weight: var(--font-weight-semibold);
    color: var(--gray-900);
    margin-bottom: var(--space-xs);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

[data-theme="dark"] .library-card-title {
    color: var(--gray-100);
}

.library-card-date {
    font-size: var(--text-xs);
    color: var(--gray-500);
}

[data-theme="dark"] .library-card-date {
    color: var(--gray-400);
}

/* Trending Section */
.trending-section {
    width: 100%;
    margin-bottom: var(--space-lg);
}

.trending-chips {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
}

.chip {
    padding: var(--space-sm) var(--space-md);
    background: var(--bg-secondary);
    border: 1px solid var(--gray-300);
    border-radius: var(--radius-pill);
    font-size: var(--text-sm);
    font-weight: var(--font-weight-medium);
    color: var(--gray-800);
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

[data-theme="dark"] .chip {
    background: var(--gray-800);
    border-color: var(--gray-600);
    color: var(--gray-200);
}

.chip:hover {
    background: var(--primary-bg);
    border-color: var(--primary-light);
    color: var(--primary);
    transform: translateY(-1px);
}

.chip:active {
    transform: translateY(0);
}

.chip-loading {
    color: var(--gray-500);
    font-style: italic;
}

[data-theme="dark"] .chip-loading {
    color: var(--gray-400);
}

/* ============================================
   Topic View - Clean Layout
   ============================================ */
.topic-screen {
    display: none;
    animation: slideIn 0.3s ease;
}

.topic-screen.active {
    display: block;
}

@keyframes slideIn {
    from { opacity: 0; transform: translateX(10px); }
    to { opacity: 1; transform: translateX(0); }
}

.topic-cover {
    width: 100%;
    max-height: 240px;
    object-fit: contain;
    border-radius: var(--radius-lg);
    margin-bottom: var(--space-lg);
    background: var(--gray-100);
}

[data-theme="dark"] .topic-cover {
    background: var(--gray-800);
}

.topic-title {
    font-size: var(--text-3xl);
    font-weight: var(--font-weight-bold);
    color: var(--gray-900);
    margin-bottom: var(--space-sm);
    line-height: var(--line-height-tight);
}

[data-theme="dark"] .topic-title {
    color: var(--gray-100);
}

.topic-subtitle {
    font-size: var(--text-base);
    color: var(--gray-600);
    margin-bottom: var(--space-lg);
}

[data-theme="dark"] .topic-subtitle {
    color: var(--gray-400);
}

/* Quick Fact Card */
.quick-fact {
    background: var(--primary-bg);
    border-left: 3px solid var(--primary);
    border-radius: var(--radius-md);
    padding: var(--space-md);
    margin-bottom: var(--space-lg);
    animation: slideDown 0.3s ease;
}

@keyframes slideDown {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

.quick-fact-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-sm);
}

.quick-fact-label {
    font-size: var(--text-sm);
    font-weight: var(--font-weight-semibold);
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

.quick-fact-toggle {
    background: none;
    border: none;
    color: var(--primary);
    font-size: var(--text-sm);
    cursor: pointer;
    font-weight: var(--font-weight-medium);
    transition: color var(--transition-fast);
    padding: var(--space-xs);
}

.quick-fact-toggle:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

.quick-fact-content {
    font-size: var(--text-base);
    line-height: var(--line-height-relaxed);
    color: var(--gray-800);
}

[data-theme="dark"] .quick-fact-content {
    color: var(--gray-200);
}

/* Wiki Summary */
.wiki-summary {
    margin-bottom: var(--space-lg);
    font-size: var(--text-base);
    line-height: var(--line-height-relaxed);
    color: var(--gray-800);
}

[data-theme="dark"] .wiki-summary {
    color: var(--gray-200);
}

.wiki-summary p {
    margin-bottom: var(--space-md);
}

.wiki-summary p:last-child {
    margin-bottom: 0;
}

/* Images Strip */
.images-strip-container {
    margin-bottom: var(--space-lg);
    overflow: hidden;
}

.images-strip {
    display: flex;
    gap: var(--space-sm);
    overflow-x: auto;
    padding-bottom: var(--space-sm);
    scrollbar-width: none;
}

.images-strip::-webkit-scrollbar {
    display: none;
}

.images-strip img {
    width: 100px;
    height: 100px;
    object-fit: contain;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    flex-shrink: 0;
    background: var(--gray-100);
}

[data-theme="dark"] .images-strip img {
    background: var(--gray-800);
}

.images-strip img:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

.see-more-btn {
    min-width: 100px;
    height: 100px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gray-100);
    border: 1px dashed var(--gray-300);
    border-radius: var(--radius-md);
    color: var(--gray-600);
    font-size: var(--text-sm);
    font-weight: var(--font-weight-medium);
    cursor: pointer;
    transition: all var(--transition-fast);
    flex-shrink: 0;
}

[data-theme="dark"] .see-more-btn {
    background: var(--gray-800);
    border-color: var(--gray-600);
    color: var(--gray-400);
}

.see-more-btn:hover {
    background: var(--primary-bg);
    border-color: var(--primary-light);
    color: var(--primary);
}

/* Related Topics */
.related-section {
    margin-bottom: var(--space-lg);
}

.related-pills {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
}

.related-pills .chip {
    background: var(--bg-secondary);
    border: 1px solid var(--gray-300);
}

.related-pills .chip:hover {
    background: var(--primary-bg);
    border-color: var(--primary-light);
    color: var(--primary);
}

/* Actions */
.actions {
    display: flex;
    gap: var(--space-sm);
    margin-bottom: var(--space-lg);
    flex-wrap: wrap;
}

.btn {
    padding: var(--space-sm) var(--space-lg);
    border: none;
    border-radius: var(--radius-md);
    font-size: var(--text-sm);
    font-weight: var(--font-weight-semibold);
    cursor: pointer;
    transition: all var(--transition-fast);
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    white-space: nowrap;
}

.btn-primary {
    background: var(--primary);
    color: white;
    box-shadow: var(--shadow-xs);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--gray-800);
    border: 1px solid var(--gray-300);
}

[data-theme="dark"] .btn-secondary {
    background: var(--gray-800);
    color: var(--gray-200);
    border-color: var(--gray-600);
}

.btn-secondary:hover {
    background: var(--gray-100);
    border-color: var(--primary-light);
    color: var(--primary);
}

[data-theme="dark"] .btn-secondary:hover {
    background: var(--gray-700);
}

/* User Note */
.user-note-section {
    margin-bottom: var(--space-lg);
}

.user-note-label {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: var(--text-sm);
    font-weight: var(--font-weight-semibold);
    color: var(--gray-800);
    margin-bottom: var(--space-sm);
}

[data-theme="dark"] .user-note-label {
    color: var(--gray-200);
}

.user-note-label i {
    color: var(--primary);
}

.user-note {
    width: 100%;
    min-height: 120px;
    padding: var(--space-md);
    background: var(--bg-secondary);
    border: 1px solid var(--gray-300);
    border-radius: var(--radius-md);
    font-size: var(--text-base);
    color: var(--gray-800);
    font-family: inherit;
    resize: vertical;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

[data-theme="dark"] .user-note {
    background: var(--gray-800);
    border-color: var(--gray-600);
    color: var(--gray-200);
}

.user-note:focus {
    border-color: var(--primary);
    outline: none;
    box-shadow: 0 0 0 3px var(--primary-bg);
}

.user-note::placeholder {
    color: var(--gray-500);
}

[data-theme="dark"] .user-note::placeholder {
    color: var(--gray-500);
}

/* ============================================
   Reader View
   ============================================ */
.reader-screen {
    display: none;
    position: fixed;
    inset: 0;
    background: var(--bg-primary);
    z-index: var(--z-modal);
    overflow-y: auto;
    animation: fadeIn 0.3s ease;
}

.reader-screen.active {
    display: block;
}

.reader-header {
    position: sticky;
    top: 0;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--gray-200);
    padding: var(--space-md) var(--space-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: var(--z-sticky);
}

.reader-title {
    font-size: var(--text-lg);
    font-weight: var(--font-weight-semibold);
    color: var(--gray-900);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

[data-theme="dark"] .reader-title {
    color: var(--gray-100);
}

.reader-close {
    width: 36px;
    height: 36px;
    border: none;
    background: var(--bg-secondary);
    color: var(--gray-700);
    border-radius: var(--radius-full);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.reader-close:hover {
    background: var(--gray-200);
    color: var(--gray-900);
}

[data-theme="dark"] .reader-close {
    background: var(--gray-800);
    color: var(--gray-300);
}

[data-theme="dark"] .reader-close:hover {
    background: var(--gray-700);
    color: var(--gray-100);
}

.reader-content {
    padding: var(--space-lg);
    max-width: 800px;
    margin: 0 auto;
}

.reader-content h1 {
    font-size: var(--text-3xl);
    font-weight: var(--font-weight-bold);
    color: var(--gray-900);
    margin-bottom: var(--space-md);
    padding-bottom: var(--space-md);
    border-bottom: 1px solid var(--gray-200);
}

[data-theme="dark"] .reader-content h1 {
    color: var(--gray-100);
    border-bottom-color: var(--gray-700);
}

.reader-content h2 {
    font-size: var(--text-2xl);
    font-weight: var(--font-weight-bold);
    color: var(--gray-900);
    margin-top: var(--space-xl);
    margin-bottom: var(--space-md);
    padding-top: var(--space-md);
    border-top: 1px solid var(--gray-200);
}

[data-theme="dark"] .reader-content h2 {
    color: var(--gray-100);
    border-top-color: var(--gray-700);
}

.reader-content h3 {
    font-size: var(--text-xl);
    font-weight: var(--font-weight-semibold);
    color: var(--gray-900);
    margin-top: var(--space-lg);
    margin-bottom: var(--space-md);
}

[data-theme="dark"] .reader-content h3 {
    color: var(--gray-100);
}

.reader-content p {
    font-size: var(--text-base);
    line-height: var(--line-height-relaxed);
    color: var(--gray-800);
    margin-bottom: var(--space-md);
}

[data-theme="dark"] .reader-content p {
    color: var(--gray-200);
}

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

.reader-content a:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

.reader-content img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-md);
    margin: var(--space-md) 0;
}

.reader-content blockquote {
    border-left: 3px solid var(--primary);
    padding-left: var(--space-md);
    margin-left: 0;
    color: var(--gray-600);
    font-style: italic;
}

[data-theme="dark"] .reader-content blockquote {
    color: var(--gray-400);
}

/* ============================================
   Library View
   ============================================ */
.library-screen {
    display: none;
    animation: fadeIn 0.3s ease;
}

.library-screen.active {
    display: block;
}

.library-header {
    margin-bottom: var(--space-lg);
}

.library-header h2 {
    font-size: var(--text-2xl);
    font-weight: var(--font-weight-bold);
    color: var(--gray-900);
    margin-bottom: var(--space-md);
}

[data-theme="dark"] .library-header h2 {
    color: var(--gray-100);
}

.library-search-wrap {
    position: relative;
    margin-bottom: var(--space-md);
}

.library-search {
    width: 100%;
    padding: var(--space-sm) var(--space-md);
    padding-right: 40px;
    background: var(--bg-secondary);
    border: 1px solid var(--gray-300);
    border-radius: var(--radius-pill);
    font-size: var(--text-base);
    color: var(--gray-900);
    font-family: inherit;
    transition: all var(--transition-fast);
}

[data-theme="dark"] .library-search {
    background: var(--gray-800);
    border-color: var(--gray-600);
    color: var(--gray-100);
}

.library-search:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-bg);
    outline: none;
}

.library-search::placeholder {
    color: var(--gray-500);
}

[data-theme="dark"] .library-search::placeholder {
    color: var(--gray-500);
}

.library-search-clear {
    position: absolute;
    right: var(--space-sm);
    top: 50%;
    transform: translateY(-50%);
    width: 32px;
    height: 32px;
    border: none;
    background: none;
    color: var(--gray-500);
    border-radius: var(--radius-full);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.library-search-clear:hover {
    background: var(--gray-200);
    color: var(--gray-800);
}

[data-theme="dark"] .library-search-clear:hover {
    background: var(--gray-700);
    color: var(--gray-100);
}

.library-tags {
    display: flex;
    gap: var(--space-sm);
    flex-wrap: wrap;
    margin-bottom: var(--space-lg);
}

.tag-chip {
    padding: var(--space-xs) var(--space-sm);
    background: var(--bg-secondary);
    border: 1px solid var(--gray-300);
    border-radius: var(--radius-pill);
    font-size: var(--text-xs);
    font-weight: var(--font-weight-medium);
    color: var(--gray-600);
    cursor: pointer;
    transition: all var(--transition-fast);
}

[data-theme="dark"] .tag-chip {
    background: var(--gray-800);
    border-color: var(--gray-600);
    color: var(--gray-400);
}

.tag-chip:hover {
    background: var(--primary-bg);
    border-color: var(--primary-light);
    color: var(--primary);
}

.tag-chip.active {
    background: var(--primary-bg);
    border-color: var(--primary);
    color: var(--primary);
}

.library-results {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.library-item {
    display: flex;
    gap: var(--space-md);
    padding: var(--space-md);
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-normal);
}

.library-item:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
    border-color: var(--primary-light);
}

.library-item img {
    width: 80px;
    height: 80px;
    object-fit: cover;
    border-radius: var(--radius-md);
    flex-shrink: 0;
    background: var(--gray-100);
}

[data-theme="dark"] .library-item img {
    background: var(--gray-800);
}

.library-item-info {
    flex: 1;
    min-width: 0;
}

.library-item-info h3 {
    font-size: var(--text-base);
    font-weight: var(--font-weight-semibold);
    color: var(--gray-900);
    margin-bottom: var(--space-xs);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

[data-theme="dark"] .library-item-info h3 {
    color: var(--gray-100);
}

.library-item-date {
    font-size: var(--text-xs);
    color: var(--gray-500);
    margin-bottom: var(--space-xs);
}

[data-theme="dark"] .library-item-date {
    color: var(--gray-400);
}

.library-item-note {
    font-size: var(--text-sm);
    color: var(--gray-600);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

[data-theme="dark"] .library-item-note {
    color: var(--gray-400);
}

.library-item-actions {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
    justify-content: center;
}

.btn-icon {
    width: 36px;
    height: 36px;
    border: none;
    background: var(--bg-secondary);
    color: var(--gray-600);
    border-radius: var(--radius-full);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.btn-icon:hover {
    background: var(--gray-200);
    color: var(--gray-800);
}

[data-theme="dark"] .btn-icon {
    background: var(--gray-800);
    color: var(--gray-400);
}

[data-theme="dark"] .btn-icon:hover {
    background: var(--gray-700);
    color: var(--gray-100);
}

.btn-icon-danger:hover {
    background: #ffebee;
    color: var(--error);
}

[data-theme="dark"] .btn-icon-danger:hover {
    background: rgba(234, 67, 53, 0.1);
}

/* ============================================
   Lightbox
   ============================================ */
.lightbox {
    display: none;
    position: fixed;
    inset: 0;
    background: var(--bg-overlay);
    z-index: var(--z-modal);
    align-items: center;
    justify-content: center;
    padding: var(--space-lg);
    animation: fadeIn 0.2s ease;
}

.lightbox.active {
    display: flex;
}

.lb-img-wrap {
    position: relative;
    max-width: 100%;
    max-height: 80vh;
}

.lb-img {
    max-width: 100%;
    max-height: 80vh;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
}

.lb-close {
    position: absolute;
    top: -40px;
    right: 0;
    width: 36px;
    height: 36px;
    border: none;
    background: var(--bg-overlay);
    color: white;
    border-radius: var(--radius-full);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    z-index: 1;
}

.lb-close:hover {
    background: var(--error);
}

.lb-nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 44px;
    height: 44px;
    border: none;
    background: var(--bg-overlay);
    color: white;
    border-radius: var(--radius-full);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.lb-nav:hover {
    background: var(--primary);
}

.lb-prev {
    left: -50px;
}

.lb-next {
    right: -50px;
}

.lb-bottom {
    position: absolute;
    bottom: -40px;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 var(--space-md);
}

.lb-caption {
    font-size: var(--text-sm);
    color: white;
    max-width: 60%;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.lb-counter {
    font-size: var(--text-sm);
    color: white;
}

/* ============================================
   History Panel - Google-style bottom sheet
   ============================================ */
.history-panel {
    display: none;
    position: fixed;
    bottom: var(--footer-height-mobile);
    left: 0;
    right: 0;
    background: var(--bg-primary);
    border-top: 1px solid var(--gray-200);
    max-height: 50vh;
    overflow-y: auto;
    z-index: var(--z-dropdown);
    animation: slideUp 0.3s ease;
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
    box-shadow: var(--shadow-lg);
}

.history-panel.open {
    display: block;
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(100%); }
    to { opacity: 1; transform: translateY(0); }
}

.history-head {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-md) var(--space-lg);
    border-bottom: 1px solid var(--gray-200);
    position: sticky;
    top: 0;
    background: var(--bg-primary);
    z-index: 1;
}

.history-head h3 {
    font-size: var(--text-lg);
    font-weight: var(--font-weight-semibold);
    color: var(--gray-900);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

[data-theme="dark"] .history-head h3 {
    color: var(--gray-100);
}

.history-body {
    padding: var(--space-md) var(--space-lg);
}

.history-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-sm) 0;
    border-bottom: 1px solid var(--gray-200);
}

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

.history-text {
    flex: 1;
    min-width: 0;
}

.history-query {
    font-size: var(--text-base);
    color: var(--gray-800);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

[data-theme="dark"] .history-query {
    color: var(--gray-200);
}

.history-time {
    font-size: var(--text-xs);
    color: var(--gray-500);
}

[data-theme="dark"] .history-time {
    color: var(--gray-400);
}

.txt-btn {
    background: none;
    border: none;
    color: var(--gray-600);
    font-size: var(--text-sm);
    cursor: pointer;
    transition: color var(--transition-fast);
    padding: var(--space-xs);
}

.txt-btn:hover {
    color: var(--gray-900);
}

[data-theme="dark"] .txt-btn {
    color: var(--gray-400);
}

[data-theme="dark"] .txt-btn:hover {
    color: var(--gray-100);
}

/* ============================================
   Achievements Panel - Google-style
   ============================================ */
.achievements-panel {
    display: none;
    position: fixed;
    bottom: var(--footer-height-mobile);
    left: 0;
    right: 0;
    background: var(--bg-primary);
    border-top: 1px solid var(--gray-200);
    max-height: 60vh;
    overflow-y: auto;
    z-index: var(--z-dropdown);
    animation: slideUp 0.3s ease;
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
    box-shadow: var(--shadow-lg);
}

.achievements-panel.open {
    display: block;
}

.achievements-head {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-md) var(--space-lg);
    border-bottom: 1px solid var(--gray-200);
    position: sticky;
    top: 0;
    background: var(--bg-primary);
    z-index: 1;
}

.achievements-head h3 {
    font-size: var(--text-lg);
    font-weight: var(--font-weight-semibold);
    color: var(--gray-900);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

[data-theme="dark"] .achievements-head h3 {
    color: var(--gray-100);
}

.achievements-body {
    padding: var(--space-md) var(--space-lg);
}

.achievement-item {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md);
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-sm);
    transition: all var(--transition-fast);
    border: 1px solid transparent;
}

.achievement-item:hover {
    background: var(--gray-100);
    border-color: var(--gray-200);
}

[data-theme="dark"] .achievement-item {
    background: var(--gray-800);
}

[data-theme="dark"] .achievement-item:hover {
    background: var(--gray-700);
}

.achievement-item.achieved {
    opacity: 1;
}

.achievement-item.locked {
    opacity: 0.6;
}

.achievement-icon {
    font-size: var(--text-2xl);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-bg);
    border-radius: var(--radius-full);
    flex-shrink: 0;
}

.achievement-item.achieved .achievement-icon {
    background: var(--primary);
    color: white;
}

.achievement-info {
    flex: 1;
    min-width: 0;
}

.achievement-name {
    font-size: var(--text-base);
    font-weight: var(--font-weight-semibold);
    color: var(--gray-900);
    margin-bottom: 2px;
}

[data-theme="dark"] .achievement-name {
    color: var(--gray-100);
}

.achievement-description {
    font-size: var(--text-sm);
    color: var(--gray-600);
    margin-bottom: 2px;
}

[data-theme="dark"] .achievement-description {
    color: var(--gray-400);
}

.achievement-points {
    font-size: var(--text-xs);
    color: var(--primary);
    font-weight: var(--font-weight-medium);
}

.achievement-badge {
    position: absolute;
    top: -4px;
    right: -4px;
    width: 20px;
    height: 20px;
    background: var(--success);
    color: white;
    border-radius: 50%;
    font-size: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 2px solid white;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

/* ============================================
   First Run Modal - Simple & Centered
   ============================================ */
.first-run-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: var(--bg-overlay);
    z-index: var(--z-modal);
}

.first-run-overlay.active {
    display: block;
}

.first-run-modal {
    display: none;
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: min(90%, 380px);
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    box-shadow: var(--shadow-xl);
    z-index: var(--z-modal);
    animation: scaleIn 0.3s ease;
    max-width: 380px;
}

.first-run-modal.active {
    display: block;
}

@keyframes scaleIn {
    from { opacity: 0; transform: translate(-50%, -50%) scale(0.9); }
    to { opacity: 1; transform: translate(-50%, -50%) scale(1); }
}

.first-run-title {
    font-size: var(--text-xl);
    font-weight: var(--font-weight-bold);
    color: var(--gray-900);
    margin-bottom: var(--space-sm);
    text-align: center;
}

[data-theme="dark"] .first-run-title {
    color: var(--gray-100);
}

.first-run-text {
    font-size: var(--text-base);
    color: var(--gray-700);
    text-align: center;
    margin-bottom: var(--space-lg);
    line-height: var(--line-height-relaxed);
}

[data-theme="dark"] .first-run-text {
    color: var(--gray-300);
}

.privacy-note {
    font-size: var(--text-sm);
    color: var(--gray-500);
    font-style: italic;
    margin-top: var(--space-sm);
    text-align: center;
}

[data-theme="dark"] .privacy-note {
    color: var(--gray-500);
}

.first-run-actions {
    display: flex;
    gap: var(--space-md);
    width: 100%;
}

.first-run-btn {
    flex: 1;
    padding: var(--space-md);
    border: none;
    border-radius: var(--radius-md);
    font-size: var(--text-base);
    font-weight: var(--font-weight-semibold);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.first-run-btn.yes {
    background: var(--primary);
    color: white;
}

.first-run-btn.yes:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

.first-run-btn.no {
    background: var(--bg-secondary);
    color: var(--gray-800);
    border: 1px solid var(--gray-300);
}

[data-theme="dark"] .first-run-btn.no {
    background: var(--gray-800);
    color: var(--gray-200);
    border-color: var(--gray-600);
}

.first-run-btn.no:hover {
    background: var(--gray-100);
    border-color: var(--primary-light);
}

[data-theme="dark"] .first-run-btn.no:hover {
    background: var(--gray-700);
}

.first-run-arrow {
    display: none;
}

/* ============================================
   Footer - Google-style
   ============================================ */
footer {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--bg-primary);
    border-top: 1px solid var(--gray-200);
    display: flex;
    justify-content: space-around;
    align-items: center;
    padding: var(--space-sm) var(--space-md);
    z-index: var(--z-fixed);
    box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.05);
}

.footer-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
    padding: var(--space-sm) var(--space-md);
    border: none;
    background: none;
    color: var(--gray-600);
    font-size: var(--text-xs);
    cursor: pointer;
    transition: all var(--transition-fast);
    border-radius: var(--radius-md);
}

.footer-btn:hover {
    color: var(--gray-900);
}

[data-theme="dark"] .footer-btn {
    color: var(--gray-400);
}

[data-theme="dark"] .footer-btn:hover {
    color: var(--gray-100);
}

.footer-btn.active {
    color: var(--primary);
}

.footer-btn.active i {
    transform: scale(1.1);
}

.footer-btn i {
    font-size: var(--text-lg);
    transition: transform var(--transition-fast);
}

.footer-btn span {
    font-weight: var(--font-weight-medium);
}

/* ============================================
   Toast Notifications
   ============================================ */
.sem-toast {
    position: fixed;
    bottom: calc(var(--footer-height-mobile) + var(--space-md));
    left: 50%;
    transform: translateX(-50%);
    background: var(--gray-900);
    color: var(--white);
    padding: var(--space-sm) var(--space-lg);
    border-radius: var(--radius-md);
    font-size: var(--text-sm);
    font-weight: var(--font-weight-medium);
    z-index: var(--z-toast);
    white-space: nowrap;
    box-shadow: var(--shadow-lg);
    pointer-events: none;
    animation: slideUp 0.3s ease;
}

/* ============================================
   Empty States
   ============================================ */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--space-3xl);
    color: var(--gray-600);
}

.empty-state i {
    font-size: var(--text-4xl);
    margin-bottom: var(--space-md);
    color: var(--gray-400);
}

.empty-state p {
    font-size: var(--text-base);
}

[data-theme="dark"] .empty-state {
    color: var(--gray-400);
}

[data-theme="dark"] .empty-state i {
    color: var(--gray-600);
}

[data-theme="dark"] .empty-state p {
    color: var(--gray-400);
}

/* ============================================
   Responsive Design
   ============================================ */
@media (min-width: 768px) {
    main {
        max-width: 720px;
        margin: 0 auto;
        padding-top: var(--space-xl);
    }
    
    .home-logo {
        font-size: var(--text-6xl);
    }
    
    .topic-cover {
        max-height: 300px;
        border-radius: var(--radius-xl);
    }
    
    .images-strip img {
        width: 120px;
        height: 120px;
    }
    
    .see-more-btn {
        min-width: 120px;
        height: 120px;
    }
    
    .library-item {
        padding: var(--space-lg);
    }
    
    .library-item img {
        width: 100px;
        height: 100px;
    }
    
    footer {
        max-width: 560px;
        left: 50%;
        transform: translateX(-50%);
    }
    
    .reader-content {
        max-width: 900px;
        padding: var(--space-xl);
    }
    
    .stats-section {
        gap: var(--space-3xl);
    }
}

@media (min-width: 1024px) {
    .home-logo {
        font-size: var(--text-6xl);
    }
    
    .topic-cover {
        max-height: 350px;
    }
    
    .images-strip img {
        width: 140px;
        height: 140px;
    }
    
    .see-more-btn {
        min-width: 140px;
        height: 140px;
    }
    
    .reader-content {
        max-width: 1000px;
    }
}

/* ============================================
   Accessibility
   ============================================ */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
    :root {
        --border-light: #000;
        --border-medium: #000;
    }
    
    [data-theme="dark"] {
        --border-light: #fff;
        --border-medium: #fff;
    }
}

/* Print Styles */
@media print {
    header,
    footer,
    .lightbox,
    .history-panel,
    .achievements-panel,
    .first-run-overlay,
    .first-run-modal,
    .actions,
    .auto-save-indicator,
    .online-indicator {
        display: none !important;
    }
    
    main {
        padding: 0;
        padding-bottom: 0;
    }
    
    .topic-screen,
    .reader-screen,
    .library-screen {
        display: block !important;
        page-break-inside: avoid;
    }
    
    img {
        max-width: 100% !important;
        height: auto !important;
    }
}


/* ============================================
   Confident product layer
   ============================================ */
:root {
  --primary: #3157d5;
  --primary-dark: #2343aa;
  --primary-bg: #eef2ff;
  --gray-900: #172033;
  --gray-800: #273248;
  --gray-600: #667085;
  --gray-300: #d9dee9;
  --bg-secondary: #f7f8fc;
  --card-border: #e4e7ec;
  --shadow-sm: 0 1px 2px rgba(15,23,42,.06);
  --shadow-md: 0 8px 24px rgba(15,23,42,.08);
  --shadow-lg: 0 16px 40px rgba(15,23,42,.12);
}
body { background: #f7f8fc; }
header { background: rgba(255,255,255,.92); backdrop-filter: blur(18px); border-bottom-color: #e4e7ec; }
.search-box { background: #fff; border-color: #d9dee9; border-radius: 14px; box-shadow: 0 2px 8px rgba(15,23,42,.04); }
.icon-btn { border-radius: 11px; box-shadow: none; }
main { max-width: 1120px; padding: 40px 28px calc(var(--footer-height-mobile) + 40px); }
.home { align-items: stretch; max-width: 1000px; margin: 0 auto; }
.home-logo, .home-sub, .home-tagline { align-self: center; }
.home-logo { letter-spacing: -.04em; }
.home-tagline { color: var(--gray-600); }
.stats-section { display: grid; grid-template-columns: 1.35fr repeat(3, 1fr); gap: 12px; width: 100%; margin: 24px 0 36px; padding: 0; }
.stat-card { position: relative; flex-direction: row; align-items: center; justify-content: flex-start; gap: 12px; padding: 18px; background: #fff; border: 1px solid var(--card-border); border-radius: 16px; text-align: left; box-shadow: var(--shadow-sm); }
.stat-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.stat-card-featured { background: linear-gradient(135deg, #3157d5, #5676e3); color: #fff; border-color: transparent; }
.stat-icon { width: 36px; height: 36px; display: grid; place-items: center; border-radius: 11px; background: var(--primary-bg); color: var(--primary); }
.stat-card-featured .stat-icon { background: rgba(255,255,255,.16); color: #fff; }
.stat-value { font-size: 20px; line-height: 1.1; }
.stat-label { color: var(--gray-600); font-size: 12px; margin-top: 4px; }
.stat-card-featured .stat-label, .stat-card-featured .stat-value { color: #fff; }
.stat-trend { margin-left: auto; font-size: 11px; opacity: .8; }
.library-section, .trending-section { background: #fff; border: 1px solid var(--card-border); border-radius: 20px; padding: 22px; margin-bottom: 18px; box-shadow: var(--shadow-sm); }
.section-label { font-size: 13px; letter-spacing: .08em; text-transform: uppercase; font-weight: 700; color: var(--gray-600); }
.trending-chips, .related-pills { gap: 9px; }
.chip { border-radius: 10px; background: #f7f8fc; border-color: #e4e7ec; padding: 9px 12px; }
.chip:hover { background: var(--primary-bg); border-color: #aebdf5; }
.reader-screen { background: #fbfcff; }
.reader-header { padding: 16px max(24px, calc((100% - 960px)/2)); background: rgba(255,255,255,.94); backdrop-filter: blur(18px); }
.reader-heading { min-width: 0; }
.reader-eyebrow, .eyebrow { display:block; font-size: 10px; letter-spacing: .12em; color: var(--primary); font-weight: 800; }
.reader-title { margin-top: 4px; }
.reader-actions { display:flex; align-items:center; gap: 8px; }
.reader-action { display:flex; align-items:center; gap:7px; border:1px solid var(--card-border); background:#fff; color:var(--gray-800); border-radius:10px; padding:9px 11px; font:inherit; cursor:pointer; }
.reader-action:hover, .reader-action.saved { border-color:#aebdf5; color:var(--primary); background:var(--primary-bg); }
.reader-content { max-width: 740px; padding: 56px 28px 100px; }
.reader-content p { font-size: 18px; line-height: 1.8; color: #354052; }
.history-panel, .achievements-panel { position: fixed; inset: 0; bottom: 0; max-height: none; border-radius: 0; padding: 0 max(24px, calc((100% - 900px)/2)); background: #f7f8fc; overflow-y:auto; z-index: var(--z-modal); }
.history-head, .achievements-head { margin: 0 -24px; padding: 26px max(24px, calc((100% - 900px)/2)); background: rgba(255,255,255,.94); backdrop-filter: blur(18px); }
.history-head h3, .achievements-head h3 { font-size: 24px; }
.panel-intro { max-width: 900px; margin: 28px auto 16px; }
.panel-intro p { color: var(--gray-600); margin-bottom: 14px; }
.panel-search { width:100%; padding:13px 16px; border:1px solid var(--card-border); border-radius:12px; background:#fff; font:inherit; }
.history-body, .achievements-body { max-width: 900px; margin:0 auto; padding: 0 0 100px; }
.history-item { width:100%; display:flex; text-align:left; align-items:center; gap:14px; padding:16px 0; background:transparent; border:0; border-bottom:1px solid var(--card-border); cursor:pointer; }
.history-icon { width:38px; height:38px; display:grid; place-items:center; background:#fff; border:1px solid var(--card-border); border-radius:12px; color:var(--primary); }
.history-text { display:flex; flex-direction:column; gap:4px; }
.history-query { font-weight:700; color:var(--gray-900); }
.history-time { color:var(--gray-600); }
.history-open { margin-left:auto; color:var(--gray-500); }
.achievement-hero { display:flex; justify-content:space-between; align-items:center; gap:20px; padding:24px; margin:28px 0 16px; border-radius:20px; color:#fff; background:linear-gradient(135deg,#172b70,#3157d5); box-shadow:var(--shadow-md); }
.achievement-hero h4 { margin:8px 0 5px; font-size:24px; }
.achievement-hero p { opacity:.78; }
.level-orb { width:82px; height:82px; flex-shrink:0; display:grid; place-items:center; align-content:center; border:1px solid rgba(255,255,255,.35); border-radius:50%; background:rgba(255,255,255,.12); }
.level-orb strong { font-size:18px; } .level-orb span { font-size:10px; opacity:.8; }
.achievement-metrics { display:grid; grid-template-columns:repeat(4,1fr); gap:10px; margin-bottom:16px; }
.achievement-metrics > div { background:#fff; border:1px solid var(--card-border); border-radius:14px; padding:16px; }
.achievement-metrics strong, .achievement-metrics span { display:block; } .achievement-metrics strong { font-size:22px; } .achievement-metrics span { color:var(--gray-600); font-size:12px; margin-top:5px; }
.next-achievement { display:flex; gap:14px; padding:18px; background:#fff; border:1px solid var(--card-border); border-radius:16px; margin-bottom:24px; }
.next-icon { font-size:28px; } .next-copy { flex:1; } .next-copy strong, .next-copy small { display:block; margin:4px 0; } .next-copy small { color:var(--gray-600); } .progress-track { height:7px; margin-top:12px; border-radius:99px; background:#edf0f6; overflow:hidden; } .progress-track span { display:block; height:100%; background:var(--primary); border-radius:inherit; } .next-copy em { font-size:11px; color:var(--gray-600); font-style:normal; }
.badge-heading { display:flex; justify-content:space-between; align-items:center; margin:10px 0; font-weight:800; } .badge-heading small { color:var(--gray-600); font-weight:400; }
.badge-grid { display:grid; grid-template-columns:repeat(3,1fr); gap:10px; }
.badge-card { padding:18px 12px; text-align:center; background:#fff; border:1px solid var(--card-border); border-radius:16px; } .badge-card.locked { opacity:.48; filter:grayscale(1); } .badge-symbol { font-size:28px; margin-bottom:8px; } .badge-card strong, .badge-card span { display:block; } .badge-card strong { font-size:13px; } .badge-card span { color:var(--gray-600); font-size:11px; margin-top:4px; }
footer { background:rgba(255,255,255,.94); backdrop-filter:blur(18px); border:1px solid var(--card-border); border-bottom:0; border-radius:18px 18px 0 0; box-shadow:0 -8px 30px rgba(15,23,42,.08); }
.footer-btn { min-width:76px; padding:10px 12px; border-radius:12px; } .footer-btn.active { background:var(--primary-bg); color:var(--primary); }
@media (max-width: 700px) { .stats-section { grid-template-columns:repeat(2,1fr); } .stat-card-featured { grid-column:span 2; } .achievement-metrics { grid-template-columns:repeat(2,1fr); } .badge-grid { grid-template-columns:repeat(2,1fr); } .reader-action span { display:none; } .reader-header { padding:14px 16px; } main { padding:28px 16px calc(var(--footer-height-mobile) + 28px); } }


/* Final polish: Home-first startup and lightweight discovery */
.home { min-height: 520px; }
.trending-section { background: transparent; border: 0; box-shadow: none; padding: 8px 0 20px; }
.trending-section .section-label { margin-bottom: 12px; }
.trending-chips { display: flex; flex-wrap: wrap; gap: 8px; }
.trending-section .chip { background: #fff; border: 1px solid var(--card-border); box-shadow: 0 1px 2px rgba(15,23,42,.04); }
.trending-section .chip:hover { transform: translateY(-1px); box-shadow: var(--shadow-sm); }
[data-theme="dark"] .trending-section .chip { background: var(--gray-800); }
.first-run-modal { border: 1px solid var(--card-border); }
.first-run-btn { min-height: 46px; }
@media (min-width: 768px) { .home { min-height: 640px; } }