/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Enhanced Color Palette */
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary-color: #ec4899;
    --secondary-dark: #db2777;
    --accent-color: #06b6d4;
    --accent-dark: #0891b2;
    --background-dark: #0f172a;
    --background-light: #1e293b;
    --surface-color: #334155;
    --surface-light: #475569;
    --text-primary: #ffffff;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --text-inverse: #1e293b;
    --border-color: #475569;
    --border-light: #64748b;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --info-color: #3b82f6;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #6366f1 0%, #ec4899 100%);
    --gradient-secondary: linear-gradient(135deg, #06b6d4 0%, #3b82f6 100%);
    --gradient-accent: linear-gradient(135deg, #8b5cf6 0%, #06b6d4 100%);
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 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);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-glow: 0 0 30px rgba(99, 102, 241, 0.3);
    
    /* Animations */
    --transition-fast: 0.2s ease-in-out;
    --transition-normal: 0.3s ease-in-out;
    --transition-slow: 0.5s ease-in-out;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--background-dark);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

/* Background Animation */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 20%, rgba(99, 102, 241, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(236, 72, 153, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(6, 182, 212, 0.05) 0%, transparent 50%);
    z-index: -1;
    animation: backgroundPulse 20s ease-in-out infinite;
}

@keyframes backgroundPulse {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 0.6; }
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: var(--transition-normal);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    transition: var(--transition-fast);
}

.nav-brand:hover {
    transform: translateY(-1px);
}

.brand-icon {
    width: 40px;
    height: 40px;
    border-radius: 12px;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-glow);
}

.brand-icon i {
    color: white;
    font-size: 1.2rem;
}

.brand-text {
    display: flex;
    flex-direction: column;
    gap: 0.1rem;
}

.brand-name {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.2;
}

.brand-tagline {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-weight: 500;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: 8px;
    transition: var(--transition-fast);
    font-weight: 500;
}

.nav-link:hover,
.nav-link.active {
    color: var(--text-primary);
    background: rgba(99, 102, 241, 0.15);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.2);
}

.nav-link.active {
    position: relative;
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 50%;
    transform: translateX(-50%);
    width: 20px;
    height: 2px;
    background: var(--gradient-primary);
    border-radius: 2px;
}

.chat-indicator {
    position: absolute;
    top: -2px;
    right: -2px;
    width: 8px;
    height: 8px;
    background: var(--success-color);
    border-radius: 50%;
    display: none;
}

.chat-indicator.active {
    display: block;
    animation: pulse 2s infinite;
}

.status-indicator {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 0.75rem;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 20px;
    border: 1px solid var(--border-color);
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--success-color);
    animation: pulse 2s infinite;
}

.status-text {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Main Container */
.main-container {
    margin-top: 70px;
    padding: 2rem;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
}

/* Hero Section */
.hero {
    position: relative;
    text-align: center;
    padding: 6rem 0;
    margin-bottom: 4rem;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

.floating-shapes {
    position: absolute;
    width: 100%;
    height: 100%;
}

.shape {
    position: absolute;
    border-radius: 50%;
    opacity: 0.1;
    animation: float 6s ease-in-out infinite;
}

.shape-1 {
    width: 80px;
    height: 80px;
    background: var(--primary-color);
    top: 20%;
    left: 10%;
    animation-delay: 0s;
}

.shape-2 {
    width: 60px;
    height: 60px;
    background: var(--secondary-color);
    top: 60%;
    right: 15%;
    animation-delay: 2s;
}

.shape-3 {
    width: 100px;
    height: 100px;
    background: var(--accent-color);
    bottom: 20%;
    left: 20%;
    animation-delay: 4s;
}

@keyframes float {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(180deg); }
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: 20px;
    color: var(--primary-light);
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 2rem;
    animation: fadeInUp 0.8s ease-out;
}

.hero-cta {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin: 2rem 0 3rem 0;
    flex-wrap: wrap;
}

.cta-button {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.875rem 2rem;
    border: none;
    border-radius: 12px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition-normal);
    text-decoration: none;
    min-width: 160px;
    justify-content: center;
}

.cta-button.primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.4);
}

.cta-button.primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.6);
}

.cta-button.secondary {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

.cta-button.secondary:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.gradient-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: gradientShift 3s ease-in-out infinite;
}

@keyframes gradientShift {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 4rem;
    max-width: 1000px;
    margin-left: auto;
    margin-right: auto;
}

.feature-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 16px;
    border: 1px solid var(--border-color);
    transition: var(--transition-normal);
    backdrop-filter: blur(10px);
}

.feature-item:hover {
    transform: translateY(-4px);
    background: rgba(255, 255, 255, 0.08);
    border-color: var(--primary-color);
    box-shadow: 0 8px 30px rgba(99, 102, 241, 0.2);
}

.feature-icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
}

.feature-icon i {
    color: white;
    font-size: 1.25rem;
}

.feature-content {
    flex: 1;
}

.feature-content h3 {
    color: var(--text-primary);
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    line-height: 1.3;
}

.feature-content p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.5;
}

.feature-item i {
    font-size: 1.5rem;
    color: var(--primary-color);
}

/* Sections */
.section {
    display: none;
    animation: fadeInUp 0.6s ease-out;
}

.section.active {
    display: block;
}

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

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.section-header p {
    font-size: 1.1rem;
    color: var(--text-secondary);
}

/* Buttons */
.btn-primary,
.btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition-fast);
    font-size: 1rem;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

/* Search Section */
.search-container {
    max-width: 800px;
    margin: 0 auto;
}

.search-box {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
}

.search-box input {
    flex: 1;
    padding: 1rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 1rem;
    transition: var(--transition-fast);
}

.search-box input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

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

/* Upload Section */
.upload-container {
    max-width: 800px;
    margin: 0 auto;
}

.upload-zone {
    border: 2px dashed var(--border-color);
    border-radius: 12px;
    padding: 3rem;
    text-align: center;
    background: rgba(255, 255, 255, 0.02);
    transition: var(--transition-normal);
    margin-bottom: 2rem;
}

.upload-zone:hover,
.upload-zone.drag-over {
    border-color: var(--primary-color);
    background: rgba(99, 102, 241, 0.05);
}

.upload-content i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.upload-content h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.upload-content p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.url-input-container {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    padding: 2rem;
    border: 1px solid var(--border-color);
}

.url-input-container h3 {
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.url-input-box {
    display: flex;
    gap: 1rem;
}

.url-input-box input {
    flex: 1;
    padding: 0.75rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 1rem;
}

.url-input-box input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

/* My Papers Section */
.mypapers-hero {
    text-align: center;
    padding: 3rem 0 2rem;
}

.mypapers-hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.mypapers-title-area {
    margin-bottom: 2rem;
}

.mypapers-icon-large {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: white;
}

.mypapers-hero h1 {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--text-primary), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 1rem;
}

.mypapers-hero p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

.mypapers-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 2rem;
}

.refresh-papers-btn, .clear-all-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 10px;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-normal);
}

.refresh-papers-btn {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: white;
}

.refresh-papers-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.3);
}

.clear-all-btn {
    background: rgba(239, 68, 68, 0.1);
    color: #ef4444;
    border: 1px solid rgba(239, 68, 68, 0.3);
}

.clear-all-btn:hover {
    background: rgba(239, 68, 68, 0.2);
    transform: translateY(-2px);
}

.mypapers-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

.mypapers-loading {
    text-align: center;
    padding: 3rem;
}

.mypapers-loading .loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid rgba(255, 255, 255, 0.1);
    border-top: 3px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

.mypapers-empty {
    text-align: center;
    padding: 4rem 2rem;
}

.empty-state {
    max-width: 400px;
    margin: 0 auto;
}

.empty-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: var(--text-secondary);
}

.empty-state h3 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.empty-state p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.empty-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.papers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 1.5rem;
    padding: 2rem 0;
}

.paper-card-mypapers {
    background: linear-gradient(145deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0.02));
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    padding: 1.5rem;
    transition: var(--transition-normal);
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.paper-card-mypapers::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
}

.paper-card-mypapers:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.3);
    border-color: rgba(99, 102, 241, 0.3);
}

.paper-card-header {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 1rem;
}

.paper-card-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    color: white;
    flex-shrink: 0;
}

.paper-card-content {
    flex: 1;
    min-width: 0;
}

.paper-card-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.paper-card-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-bottom: 1rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.paper-card-meta span {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.paper-card-actions {
    display: flex;
    gap: 0.5rem;
}

.paper-action-btn {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.6rem 1rem;
    border: none;
    border-radius: 8px;
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-normal);
}

.paper-action-btn.primary {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: white;
}

.paper-action-btn.primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.3);
}

.paper-action-btn.secondary {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.paper-action-btn.secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-2px);
}

.paper-action-btn.danger {
    background: rgba(239, 68, 68, 0.1);
    color: #ef4444;
    border: 1px solid rgba(239, 68, 68, 0.3);
}

.paper-action-btn.danger:hover {
    background: rgba(239, 68, 68, 0.2);
}

/* Chat Section */
.chat-container {
    background: linear-gradient(145deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0.02));
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    overflow: hidden;
    backdrop-filter: blur(10px);
    display: flex;
    flex-direction: column;
    height: 75vh;
    max-height: 800px;
}

.chat-header {
    flex-shrink: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 2rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    background: rgba(255, 255, 255, 0.03);
}

.chat-title {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.chat-icon {
    background: linear-gradient(135deg, #10b981, #06d6a0);
    padding: 1rem;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.chat-icon i {
    font-size: 1.5rem;
    color: white;
}

.chat-title-text h3 {
    color: #ffffff;
    font-size: 1.5rem;
    font-weight: 600;
    margin: 0 0 0.5rem 0;
}

.chat-title-text p {
    color: #8b949e;
    margin: 0;
    font-size: 0.95rem;
}

.chat-status .status-indicator.online .status-dot {
    background: #10b981;
}

.chat-messages-container {
    flex-grow: 1;
    padding: 2rem;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    max-width: 1000px;
    margin: 0 auto;
}

/* Custom Scrollbar */
.chat-messages-container::-webkit-scrollbar {
    width: 8px;
}

.chat-messages-container::-webkit-scrollbar-track {
    background: rgba(0, 0, 0, 0.2);
    border-radius: 4px;
}

.chat-messages-container::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 4px;
}

.chat-messages-container::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.3);
}

.welcome-avatar {
    position: relative;
    flex-shrink: 0;
}

.avatar-icon {
    background: linear-gradient(135deg, #10b981, #06d6a0);
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.avatar-icon i {
    font-size: 1.5rem;
    color: white;
}

.avatar-status {
    position: absolute;
    bottom: 2px;
    right: 2px;
    width: 14px;
    height: 14px;
    background: #10b981;
    border: 2px solid #0f172a;
    border-radius: 50%;
}

.welcome-content h4 {
    color: #ffffff;
    font-size: 1.2rem;
    margin: 0 0 0.75rem 0;
}

.chat-input-area {
    flex-shrink: 0;
    padding: 1rem 2rem 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    background: rgba(0, 0, 0, 0.2);
}

.quick-questions-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
    justify-content: center;
}

.quick-question-chip {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: #e6edf3;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.85rem;
    transition: all 0.2s ease;
}

.quick-question-chip:hover {
    background: rgba(124, 58, 237, 0.3);
    border-color: #7c3aed;
    color: #fff;
    transform: translateY(-2px);
}

.chat-input-container .input-wrapper {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    background: rgba(0, 0, 0, 0.3);
    border-radius: 12px;
    padding: 0.5rem 0.5rem 0.5rem 1rem;
    border: 1px solid rgba(255, 255, 255, 0.15);
    transition: all 0.2s ease;
}

.chat-input-container .input-wrapper:focus-within {
    border-color: #7c3aed;
    box-shadow: 0 0 0 3px rgba(124, 58, 237, 0.2);
}

.chat-input-container textarea {
    flex-grow: 1;
    background: transparent;
    border: none;
    color: #fff;
    font-size: 1rem;
    resize: none;
    padding: 0.5rem 0;
    max-height: 120px;
    line-height: 1.5;
}

.chat-input-container textarea:focus {
    outline: none;
}

.chat-input-container .send-btn-panel {
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    border-radius: 8px;
    font-size: 1rem;
}

/* --- Chat Bubble Styles --- */
.chat-message {
    display: flex;
    margin-bottom: 1.5rem;
    max-width: 80%;
    animation: messageSlideIn 0.3s ease-out;
}

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

.message-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    flex-shrink: 0;
}

.message-bubble {
    padding: 0.75rem 1.25rem;
    border-radius: 18px;
    position: relative;
    line-height: 1.6;
}

.message-content p {
    margin: 0;
    white-space: pre-wrap;
    word-wrap: break-word;
}

.message-meta {
    font-size: 0.75rem;
    color: #8b949e;
    padding-top: 0.5rem;
}

/* Assistant Bubble */
.chat-message.assistant {
    align-self: flex-start;
}

.chat-message.assistant .message-avatar {
    background: linear-gradient(135deg, #10b981, #06d6a0);
    color: white;
    margin-right: 1rem;
}

.chat-message.assistant .message-bubble {
    background: #1f2937;
    border: 1px solid #374151;
    border-top-left-radius: 4px;
    color: #e6edf3;
}

/* User Bubble */
.chat-message.user {
    align-self: flex-end;
    flex-direction: row-reverse;
    margin-left: auto;
}

.chat-message.user .message-avatar {
    background: linear-gradient(135deg, #7c3aed, #a855f7);
    color: white;
    margin-left: 1rem;
}

.chat-message.user .message-bubble {
    background: #4338ca;
    color: #e0e7ff;
    border-top-right-radius: 4px;
}

.chat-message.user .message-meta {
    text-align: right;
    color: #c7d2fe;
}

/* Typing Indicator */
.typing-indicator {
    display: flex;
    align-items: center;
    margin-bottom: 1.5rem;
    max-width: 80%;
    align-self: flex-start;
}

.typing-indicator .message-bubble {
    padding: 0.75rem 1.25rem;
    background: #1f2937;
    border: 1px solid #374151;
    border-radius: 18px;
    border-top-left-radius: 4px;
}

.typing-dots {
    display: flex;
    gap: 0.3rem;
    align-items: center;
}

.typing-dots .dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: #9ca3af;
    animation: typingAnimation 1.4s infinite ease-in-out both;
}
.typing-dots .dot:nth-child(1) { animation-delay: -0.32s; }
.typing-dots .dot:nth-child(2) { animation-delay: -0.16s; }
.typing-dots .dot:nth-child(3) { animation-delay: 0s; }

@keyframes typingAnimation {
    0%, 80%, 100% { transform: scale(0.5); opacity: 0.5; }
    40% { transform: scale(1.0); opacity: 1; }
}

.chat-messages-container {
    display: flex;
    flex-direction: column;
}

/* Results Container */
.results-container {
    margin-top: 2rem;
}

.paper-card,
.result-card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1rem;
    transition: var(--transition-normal);
}

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

.paper-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.paper-authors {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.paper-meta {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.paper-summary {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1rem;
}

.paper-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.paper-actions .btn-primary,
.paper-actions .btn-secondary {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(15, 23, 42, 0.9);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    backdrop-filter: blur(5px);
}

.loading-overlay.active {
    display: flex;
}

.loading-content {
    text-align: center;
    color: var(--text-primary);
}

.loading-spinner {
    width: 50px;
    height: 50px;
    border: 3px solid var(--border-color);
    border-top: 3px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    top: 90px;
    right: 20px;
    z-index: 10000;
}

.toast {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
    padding: 1rem 1.5rem;
    border-radius: 8px;
    margin-bottom: 0.5rem;
    border-left: 4px solid var(--primary-color);
    backdrop-filter: blur(10px);
    animation: toastSlideIn 0.3s ease-out;
    max-width: 350px;
}

.toast.success {
    border-left-color: var(--success-color);
}

.toast.error {
    border-left-color: var(--error-color);
}

.toast.warning {
    border-left-color: var(--warning-color);
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .nav-container {
        padding: 0 1rem;
    }
    
    .nav-links {
        gap: 1rem;
    }
    
    .nav-link span {
        display: none;
    }
    
    .main-container {
        padding: 1rem;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-features {
        grid-template-columns: 1fr;
    }
    
    .search-box,
    .url-input-box,
    .chat-input-box {
        flex-direction: column;
    }
    
    .upload-zone {
        padding: 2rem 1rem;
    }
    
    .paper-actions {
        flex-direction: column;
    }
    
    .message-content {
        max-width: 85%;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .section-header h2 {
        font-size: 2rem;
    }
    
    .upload-content i {
        font-size: 2rem;
    }
    
    .upload-content h3 {
        font-size: 1.25rem;
    }
}

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

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

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

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-color);
}

/* Selection */
::selection {
    background: rgba(99, 102, 241, 0.3);
    color: var(--text-primary);
}

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

/* Enhanced Section Headers */
.section-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 3rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.section-icon {
    width: 60px;
    height: 60px;
    border-radius: 16px;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.section-icon i {
    color: white;
    font-size: 1.5rem;
}

.section-title {
    flex: 1;
}

.section-title h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.section-title p {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* Enhanced Search Page */
.search-hero {
    padding: 2rem 0 4rem;
    text-align: center;
}

.search-hero-content {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 2rem;
}

.search-title-area {
    margin-bottom: 3rem;
}

.search-icon-large {
    width: 80px;
    height: 80px;
    border-radius: 20px;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 2rem;
    box-shadow: 0 12px 40px rgba(99, 102, 241, 0.3);
    animation: float 6s ease-in-out infinite;
}

.search-icon-large i {
    font-size: 2.5rem;
    color: white;
}

.search-title-area h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.search-title-area p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.6;
}

/* Enhanced Search Box */
.search-box-enhanced {
    margin-bottom: 4rem;
}

.search-input-container {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.search-input-wrapper {
    flex: 1;
    position: relative;
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid var(--border-color);
    border-radius: 20px;
    padding: 0.75rem 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    transition: var(--transition-normal);
    backdrop-filter: blur(10px);
}

.search-input-wrapper:focus-within {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.1);
    background: rgba(255, 255, 255, 0.08);
}

.search-icon {
    color: var(--text-muted);
    font-size: 1.25rem;
    transition: var(--transition-fast);
}

.search-input-wrapper:focus-within .search-icon {
    color: var(--primary-color);
}

.search-input-wrapper input {
    flex: 1;
    padding: 0.75rem 0;
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-size: 1.125rem;
    font-weight: 500;
}

.search-input-wrapper input:focus {
    outline: none;
}

.search-input-wrapper input::placeholder {
    color: var(--text-muted);
    font-weight: 400;
}

.search-submit-btn {
    padding: 0.75rem 1.5rem;
    border-radius: 16px;
    border: none;
    background: var(--gradient-primary);
    color: white;
    cursor: pointer;
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
    font-size: 1rem;
}

.search-submit-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.4);
}

.search-actions {
    display: flex;
    gap: 0.5rem;
}

.voice-search-btn,
.advanced-search-btn {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.voice-search-btn:hover,
.advanced-search-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--primary-color);
    border-color: var(--primary-color);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.2);
}

.advanced-search-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.advanced-search-btn.active:hover {
    background: var(--primary-dark);
}

/* Advanced Filters */
.advanced-filters {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 1.5rem;
    margin-top: 1rem;
    display: none;
    animation: slideDown 0.3s ease-out;
    backdrop-filter: blur(10px);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.advanced-filters.show {
    display: block;
}

.filters-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.5rem;
    align-items: end;
}

@media (max-width: 768px) {
    .filters-row {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
}

.filter-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.filter-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.filter-label i {
    color: var(--primary-color);
    font-size: 1rem;
}

.filter-select {
    padding: 0.75rem;
    background: var(--background-dark);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: var(--transition-fast);
    appearance: none;
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='m6 8 4 4 4-4'/%3e%3c/svg%3e");
    background-position: right 0.5rem center;
    background-repeat: no-repeat;
    background-size: 1.5em 1.5em;
    padding-right: 2.5rem;
}

.filter-select:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--primary-color);
}

.filter-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
    background: rgba(255, 255, 255, 0.08);
}

.filter-select option {
    background: var(--background-dark);
    color: var(--text-primary);
    padding: 0.5rem;
    border: none;
}

.filter-select option:hover,
.filter-select option:checked {
    background: var(--primary-color);
    color: white;
}

/* Quick Search Categories */
.quick-search-section {
    margin-bottom: 3rem;
}

.quick-search-section h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 2rem;
    color: var(--text-primary);
    text-align: center;
}

.quick-search-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.quick-search-card {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    cursor: pointer;
    transition: var(--transition-normal);
    text-align: left;
    backdrop-filter: blur(10px);
}

.quick-search-card:hover {
    transform: translateY(-4px);
    background: rgba(255, 255, 255, 0.08);
    border-color: var(--primary-color);
    box-shadow: 0 12px 40px rgba(99, 102, 241, 0.2);
}

.quick-search-card .card-icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.quick-search-card .card-icon i {
    font-size: 1.5rem;
    color: white;
}

.quick-search-card .card-content h4 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
    color: var(--text-primary);
}

.quick-search-card .card-content span {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* Search Tips */
.search-tips {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    margin-bottom: 3rem;
    overflow: hidden;
}

.tips-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.05);
    cursor: pointer;
}

.tips-header h3 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin: 0;
    color: var(--text-primary);
    font-size: 1.125rem;
}

.tips-header i {
    color: var(--accent-color);
}

.tips-toggle {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition-fast);
}

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

.tips-content {
    padding: 0 1.5rem 1.5rem;
    display: none;
}

.tips-content.show {
    display: block;
    animation: slideDown 0.3s ease-out;
}

.tips-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.tip-item {
    display: flex;
    gap: 1rem;
    padding: 1rem;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
}

.tip-icon {
    width: 40px;
    height: 40px;
    border-radius: 10px;
    background: var(--gradient-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.tip-icon i {
    font-size: 1rem;
    color: white;
}

.tip-content h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.tip-content p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.tip-content code {
    background: rgba(99, 102, 241, 0.1);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-size: 0.8rem;
    color: var(--primary-light);
}

/* Recent Searches */
.recent-searches {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 1.5rem;
    margin-bottom: 3rem;
}

.recent-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.recent-header h3 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin: 0;
    color: var(--text-primary);
    font-size: 1.125rem;
}

.clear-history {
    background: none;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.5rem 0.75rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition-fast);
    font-size: 0.875rem;
}

.clear-history:hover {
    border-color: var(--error-color);
    color: var(--error-color);
}

/* Enhanced Placeholder */
.search-placeholder-enhanced {
    text-align: center;
    padding: 4rem 2rem;
}

.placeholder-animation {
    margin-bottom: 2rem;
}

.floating-papers {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 2rem;
}

.paper-icon {
    font-size: 3rem;
    animation: floatPaper 3s ease-in-out infinite;
    opacity: 0.7;
}

.paper-icon:nth-child(1) { animation-delay: 0s; }
.paper-icon:nth-child(2) { animation-delay: 1s; }
.paper-icon:nth-child(3) { animation-delay: 2s; }

@keyframes floatPaper {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-10px); }
}

.search-placeholder-enhanced h3 {
    font-size: 1.75rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.search-placeholder-enhanced p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.placeholder-stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin-top: 3rem;
}

.placeholder-stats .stat {
    text-align: center;
}

.placeholder-stats .stat strong {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

.placeholder-stats .stat span {
    font-size: 0.875rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Enhanced Search Suggestions */
.search-suggestions-dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--background-light);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    margin-top: 0.5rem;
    padding: 1rem;
    z-index: 100;
    box-shadow: var(--shadow-xl);
    backdrop-filter: blur(20px);
    display: none;
}

.search-suggestions-dropdown.show {
    display: block;
    animation: slideDown 0.3s ease-out;
}

.suggestions-section {
    margin-bottom: 1rem;
}

.suggestions-section:last-child {
    margin-bottom: 0;
}

.suggestions-section h4 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.suggestion-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem;
    cursor: pointer;
    transition: var(--transition-fast);
    border-radius: 8px;
    margin-bottom: 0.25rem;
}

.suggestion-item:hover {
    background: rgba(99, 102, 241, 0.1);
    color: var(--text-primary);
}

.suggestion-item i {
    color: var(--text-muted);
    width: 16px;
    text-align: center;
}

.suggestion-item.trending i {
    color: var(--warning-color);
}

.suggestion-item span {
    flex: 1;
    color: var(--text-secondary);
    font-weight: 500;
}

.suggestion-item small {
    color: var(--text-muted);
    font-size: 0.75rem;
}

.trending-badge {
    background: var(--warning-color);
    color: var(--text-inverse);
    padding: 0.15rem 0.5rem;
    border-radius: 10px;
    font-size: 0.7rem;
    font-weight: 600;
}

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

/* Page System */
.page {
    display: none;
    min-height: 100vh;
}

.page.active {
    display: block;
}

/* Landing Page Styles */
.landing-nav {
    background: rgba(15, 23, 42, 0.98);
    backdrop-filter: blur(20px);
}

.landing-nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-cta-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: var(--gradient-primary);
    border: none;
    border-radius: 12px;
    color: white;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-normal);
    text-decoration: none;
}

.nav-cta-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.4);
}

/* Features Section */
.features-section {
    padding: 6rem 0;
    background: rgba(255, 255, 255, 0.02);
    border-top: 1px solid var(--border-color);
}

.features-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.features-header {
    text-align: center;
    margin-bottom: 4rem;
}

.features-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.features-header p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.feature-card {
    padding: 2rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    text-align: center;
    transition: var(--transition-normal);
    backdrop-filter: blur(10px);
}

.feature-card:hover {
    transform: translateY(-8px);
    border-color: var(--primary-color);
    background: rgba(255, 255, 255, 0.08);
    box-shadow: 0 12px 40px rgba(99, 102, 241, 0.2);
}

.card-icon {
    width: 72px;
    height: 72px;
    border-radius: 16px;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.3);
}

.card-icon i {
    font-size: 2rem;
    color: white;
}

.feature-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.6;
    font-size: 1rem;
}

/* About Section */
.about-section {
    padding: 6rem 0;
    background: rgba(255, 255, 255, 0.01);
}

.about-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 2rem;
    text-align: center;
}

.about-content h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 2rem;
    color: var(--text-primary);
}

.about-content p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 3rem;
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.5rem;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 1rem;
    font-weight: 500;
}

/* Footer */
.landing-footer {
    background: var(--background-light);
    border-top: 1px solid var(--border-color);
    padding: 3rem 0;
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    text-align: center;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.footer-brand .brand-icon {
    width: 32px;
    height: 32px;
}

.footer-brand .brand-name {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

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

/* App Page Styles */
.app-nav {
    background: rgba(15, 23, 42, 0.95);
}

.back-to-landing {
    width: 44px;
    height: 44px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.back-to-landing:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
    border-color: var(--primary-color);
    transform: translateY(-1px);
}

/* Smooth scrolling for landing page */
html {
    scroll-behavior: smooth;
}

/* Page transitions */
.page {
    opacity: 0;
    transition: opacity 0.5s ease-in-out;
}

.page.active {
    opacity: 1;
}

/* Mobile responsive updates */
@media (max-width: 768px) {
    .landing-nav-links {
        gap: 1rem;
    }
    
    .nav-cta-btn {
        padding: 0.5rem 1rem;
        font-size: 0.875rem;
    }
    
    .features-header h2,
    .about-content h2 {
        font-size: 2rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .feature-card {
        padding: 1.5rem;
    }
    
    .about-stats {
        grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
        gap: 1.5rem;
    }
    
    .stat-number {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .landing-nav-links .nav-link span,
    .nav-cta-btn span {
        display: none;
    }
    
    .features-section,
    .about-section {
        padding: 4rem 0;
    }
    
    .features-header h2,
    .about-content h2 {
        font-size: 1.75rem;
    }
    
    .hero-cta {
        flex-direction: column;
        align-items: center;
    }
    
    .cta-button {
        min-width: 200px;
    }
}

/* Enhanced Upload Page */
.upload-hero {
    padding: 2rem 0 4rem;
    text-align: center;
}

.upload-hero-content {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 2rem;
}

.upload-title-area {
    margin-bottom: 3rem;
}

.upload-icon-large {
    width: 80px;
    height: 80px;
    border-radius: 20px;
    background: var(--gradient-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 2rem;
    box-shadow: 0 12px 40px rgba(6, 182, 212, 0.3);
    animation: float 6s ease-in-out infinite;
}

.upload-icon-large i {
    font-size: 2.5rem;
    color: white;
}

.upload-title-area h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: var(--gradient-secondary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.upload-title-area p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.6;
}

/* Enhanced Upload Methods */
.upload-methods-enhanced {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-bottom: 3rem;
}

@media (max-width: 768px) {
    .upload-methods-enhanced {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
}

.upload-method-card {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 2rem;
    transition: var(--transition-normal);
    backdrop-filter: blur(10px);
    position: relative;
    overflow: hidden;
}

.upload-method-card:hover {
    transform: translateY(-4px);
    border-color: var(--primary-color);
    box-shadow: 0 12px 40px rgba(99, 102, 241, 0.15);
}

.primary-upload:hover {
    border-color: var(--accent-color);
    box-shadow: 0 12px 40px rgba(6, 182, 212, 0.15);
}

.upload-card-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.upload-card-icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.secondary-upload .upload-card-icon {
    background: var(--gradient-secondary);
}

.upload-card-icon i {
    font-size: 1.5rem;
    color: white;
}

.upload-card-title h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
    color: var(--text-primary);
}

.upload-card-title p {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin: 0;
}

/* Upload Drop Zone */
.upload-drop-zone {
    border: 2px dashed var(--border-color);
    border-radius: 16px;
    padding: 2rem;
    text-align: center;
    transition: var(--transition-normal);
    cursor: pointer;
    margin-bottom: 1.5rem;
    background: rgba(255, 255, 255, 0.02);
}

.upload-drop-zone:hover,
.upload-drop-zone.drag-over {
    border-color: var(--accent-color);
    background: rgba(6, 182, 212, 0.05);
    transform: scale(1.02);
}

.drop-zone-content {
    pointer-events: none;
}

.upload-animation {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.upload-cloud {
    font-size: 3rem;
    color: var(--accent-color);
    animation: float 3s ease-in-out infinite;
}

.upload-arrow {
    font-size: 2rem;
    color: var(--text-muted);
    animation: bounce 2s ease-in-out infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.drop-zone-content h4 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.drop-zone-content p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.supported-formats {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.format-badge {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 0.75rem;
    border-radius: 8px;
    font-size: 0.875rem;
    font-weight: 500;
}

.format-badge.pdf {
    background: rgba(220, 53, 69, 0.1);
    color: #dc3545;
    border: 1px solid rgba(220, 53, 69, 0.2);
}

.format-badge.docx {
    background: rgba(0, 123, 255, 0.1);
    color: #007bff;
    border: 1px solid rgba(0, 123, 255, 0.2);
}

.format-badge.txt {
    background: rgba(108, 117, 125, 0.1);
    color: #6c757d;
    border: 1px solid rgba(108, 117, 125, 0.2);
}

.upload-specs {
    display: flex;
    justify-content: center;
    gap: 2rem;
    font-size: 0.875rem;
    color: var(--text-muted);
}

.upload-specs span {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.upload-actions {
    text-align: center;
}

.browse-btn {
    padding: 0.75rem 2rem;
    background: var(--gradient-secondary);
    border: none;
    border-radius: 12px;
    color: white;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-normal);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.browse-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(6, 182, 212, 0.4);
}

/* Enhanced URL Input */
.url-input-enhanced {
    margin-bottom: 2rem;
}

.url-input-wrapper {
    display: flex;
    align-items: center;
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid var(--border-color);
    border-radius: 16px;
    padding: 0.75rem;
    gap: 1rem;
    transition: var(--transition-normal);
}

.url-input-wrapper:focus-within {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 4px rgba(6, 182, 212, 0.1);
}

.url-icon {
    color: var(--text-muted);
    font-size: 1.125rem;
}

.url-input-wrapper input {
    flex: 1;
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-size: 1rem;
    padding: 0.5rem 0;
}

.url-input-wrapper input:focus {
    outline: none;
}

.url-input-wrapper .analyze-btn {
    padding: 0.5rem 1rem;
    background: var(--gradient-secondary);
    border: none;
    border-radius: 8px;
    color: white;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.url-input-wrapper .analyze-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 12px rgba(6, 182, 212, 0.4);
}

/* URL Suggestions */
.url-suggestions {
    margin-bottom: 1.5rem;
}

.url-suggestions h4 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.source-buttons {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.5rem;
}

.source-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 0.75rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition-fast);
    font-size: 0.875rem;
}

.source-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--accent-color);
    color: var(--text-primary);
}

/* Example URLs */
.url-examples-details {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
}

.url-examples-details summary {
    padding: 0.75rem;
    background: rgba(255, 255, 255, 0.05);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: var(--transition-fast);
}

.url-examples-details summary:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
}

.example-list {
    padding: 0.5rem;
}

.example-url {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    width: 100%;
    padding: 0.75rem;
    background: transparent;
    border: 1px solid transparent;
    border-radius: 8px;
    text-align: left;
    cursor: pointer;
    transition: var(--transition-fast);
    margin-bottom: 0.25rem;
}

.example-url:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--border-color);
}

.example-url i {
    color: var(--text-muted);
    flex-shrink: 0;
}

.example-url span {
    flex: 1;
    color: var(--text-secondary);
    font-size: 0.875rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.example-url small {
    color: var(--text-muted);
    font-size: 0.75rem;
}

/* Upload Tips */
.upload-tips {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    overflow: hidden;
}

.upload-tips .tips-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.05);
    cursor: pointer;
}

.upload-tips .tips-content {
    padding: 0 1.5rem 1.5rem;
    display: none;
}

.upload-tips .tips-content.show {
    display: block;
    animation: slideDown 0.3s ease-out;
}

/* Enhanced Upload Progress */
.upload-progress-enhanced {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 2rem;
    margin-bottom: 2rem;
    backdrop-filter: blur(10px);
}

.progress-container {
    max-width: 800px;
    margin: 0 auto;
}

.progress-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 2rem;
}

.progress-title h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.progress-title p {
    color: var(--text-secondary);
    margin: 0;
}

.progress-stats {
    text-align: right;
}

.progress-percentage {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-color);
    margin-bottom: 0.25rem;
}

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

.progress-bar-container {
    margin-bottom: 2rem;
}

.progress-bar {
    height: 12px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 6px;
    overflow: hidden;
    position: relative;
}

.progress-fill {
    height: 100%;
    background: var(--gradient-secondary);
    width: 0%;
    transition: width 0.5s ease;
    position: relative;
}

.progress-glow {
    position: absolute;
    top: 0;
    right: 0;
    width: 20px;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.4));
    animation: glow 2s ease-in-out infinite;
}

@keyframes glow {
    0%, 100% { opacity: 0; }
    50% { opacity: 1; }
}

.progress-steps-enhanced {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1rem;
}

@media (max-width: 768px) {
    .progress-steps-enhanced {
        grid-template-columns: repeat(2, 1fr);
        gap: 1.5rem;
    }
}

.progress-step {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    opacity: 0.4;
    transition: var(--transition-normal);
}

.progress-step.active {
    opacity: 1;
}

.step-icon {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 0.75rem;
    transition: var(--transition-normal);
}

.progress-step.active .step-icon {
    background: var(--gradient-secondary);
    box-shadow: 0 4px 12px rgba(6, 182, 212, 0.4);
}

.step-icon i {
    font-size: 1.25rem;
    color: var(--text-muted);
}

.progress-step.active .step-icon i {
    color: white;
}

.step-content h4 {
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
    color: var(--text-secondary);
}

.progress-step.active .step-content h4 {
    color: var(--text-primary);
}

.step-content p {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin: 0;
}

/* Enhanced Upload Placeholder */
.upload-placeholder-enhanced {
    text-align: center;
    padding: 4rem 2rem;
}

.floating-documents {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 2rem;
}

.doc-icon {
    font-size: 3rem;
    animation: floatDoc 3s ease-in-out infinite;
    opacity: 0.7;
}

.doc-icon:nth-child(1) { animation-delay: 0s; }
.doc-icon:nth-child(2) { animation-delay: 1s; }
.doc-icon:nth-child(3) { animation-delay: 2s; }

@keyframes floatDoc {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-10px); }
}

.upload-placeholder-enhanced h3 {
    font-size: 1.75rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.upload-placeholder-enhanced p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.placeholder-features {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-top: 2rem;
}

@media (max-width: 768px) {
    .placeholder-features {
        flex-direction: column;
        gap: 1rem;
    }
}

.placeholder-features .feature {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-secondary);
}

.placeholder-features .feature i {
    color: var(--accent-color);
}

/* Enhanced Chat Page */
.chat-hero {
    padding: 2rem 0 3rem;
    text-align: center;
}

.chat-hero-content {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 2rem;
}

.chat-title-area {
    margin-bottom: 2rem;
}

.chat-icon-large {
    width: 80px;
    height: 80px;
    border-radius: 20px;
    background: var(--gradient-accent);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 2rem;
    box-shadow: 0 12px 40px rgba(139, 92, 246, 0.3);
    animation: float 6s ease-in-out infinite;
}

.chat-icon-large i {
    font-size: 2.5rem;
    color: white;
}

.chat-title-area h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.chat-title-area p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.6;
}

/* Enhanced Chat Status */
.chat-status-enhanced {
    margin-bottom: 2rem;
}

.status-card {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 1.5rem;
    backdrop-filter: blur(10px);
    transition: var(--transition-normal);
}

.status-card:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--accent-color);
}

.status-icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    background: var(--gradient-accent);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.status-icon i {
    font-size: 1.5rem;
    color: white;
}

.status-info {
    flex: 1;
}

.status-info h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
    color: var(--text-primary);
}

.status-info p {
    color: var(--text-secondary);
    margin: 0;
    font-size: 0.9rem;
}

.status-actions {
    display: flex;
    gap: 0.5rem;
}

.quick-action-btn {
    width: 40px;
    height: 40px;
    border-radius: 10px;
    border: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.quick-action-btn:hover {
    background: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
    transform: scale(1.05);
}

/* Enhanced Chat Container */
.chat-container-enhanced {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    overflow: hidden;
    backdrop-filter: blur(10px);
    margin-bottom: 2rem;
}

.chat-messages-container {
    height: 500px;
    overflow-y: auto;
    padding: 2rem;
    scroll-behavior: smooth;
}

.chat-messages-container::-webkit-scrollbar {
    width: 6px;
}

.chat-messages-container::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 3px;
}

.chat-messages-container::-webkit-scrollbar-thumb {
    background: var(--accent-color);
    border-radius: 3px;
}

/* Enhanced Welcome Message */
.welcome-message-enhanced {
    background: rgba(139, 92, 246, 0.05);
    border: 1px solid rgba(139, 92, 246, 0.2);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
}

.message-avatar-enhanced {
    position: relative;
    margin-right: 1rem;
    flex-shrink: 0;
}

.avatar-icon {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--gradient-accent);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(139, 92, 246, 0.3);
}

.avatar-icon i {
    font-size: 1.5rem;
    color: white;
}

.avatar-status {
    position: absolute;
    bottom: 2px;
    right: 2px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    border: 2px solid var(--background-dark);
}

.avatar-status.online {
    background: var(--success-color);
}

.avatar-status.typing {
    background: var(--warning-color);
    animation: pulse 2s infinite;
}

.message-content-enhanced {
    flex: 1;
}

.message-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.message-sender {
    font-weight: 600;
    color: var(--text-primary);
}

.message-time {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.message-badge {
    padding: 0.2rem 0.5rem;
    border-radius: 10px;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
}

.message-badge.ai {
    background: var(--gradient-accent);
    color: white;
}

/* Welcome Message Content */
.welcome-intro {
    margin-bottom: 2rem;
}

.welcome-intro h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.welcome-intro p {
    color: var(--text-secondary);
    line-height: 1.6;
}

.capabilities-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.capability-item {
    display: flex;
    gap: 1rem;
    padding: 1rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    transition: var(--transition-fast);
}

.capability-item:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: var(--accent-color);
}

.capability-icon {
    width: 40px;
    height: 40px;
    border-radius: 10px;
    background: var(--gradient-accent);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.capability-icon i {
    font-size: 1.125rem;
    color: white;
}

.capability-content h4 {
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
    color: var(--text-primary);
}

.capability-content p {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin: 0;
}

.getting-started {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
}

.getting-started p {
    margin-bottom: 1rem;
    color: var(--text-primary);
    font-weight: 600;
}

.getting-started ol {
    margin: 0;
    padding-left: 1.5rem;
    color: var(--text-secondary);
}

.getting-started li {
    margin-bottom: 0.5rem;
    line-height: 1.5;
}

/* Chat Loading Indicator */
.chat-loading {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    margin-bottom: 1rem;
}

.typing-indicator {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1rem 1.5rem;
}

.typing-dots {
    display: flex;
    gap: 0.25rem;
}

.typing-dots .dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--accent-color);
    animation: typingDots 1.4s infinite ease-in-out;
}

.typing-dots .dot:nth-child(1) { animation-delay: -0.32s; }
.typing-dots .dot:nth-child(2) { animation-delay: -0.16s; }

@keyframes typingDots {
    0%, 80%, 100% { transform: scale(0.8); opacity: 0.5; }
    40% { transform: scale(1); opacity: 1; }
}

.typing-text {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-style: italic;
}

/* Enhanced Chat Input */
.chat-input-enhanced {
    border-top: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.02);
}

/* Smart Suggestions */
.smart-suggestions {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.suggestions-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.suggestions-header h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.suggestions-toggle {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition-fast);
    padding: 0.25rem;
}

.suggestions-toggle:hover {
    color: var(--accent-color);
}

.suggestions-content {
    display: block;
    animation: slideDown 0.3s ease-out;
}

.suggestions-content.collapsed {
    display: none;
}

.suggestion-categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

.suggestion-category h5 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.suggestion-chip-enhanced {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    width: 100%;
    padding: 0.75rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition-fast);
    margin-bottom: 0.5rem;
    text-align: left;
}

.suggestion-chip-enhanced:hover {
    background: rgba(139, 92, 246, 0.1);
    border-color: var(--accent-color);
    color: var(--text-primary);
}

.suggestion-chip-enhanced i {
    color: var(--accent-color);
    flex-shrink: 0;
}

/* Chat Input Wrapper */
.chat-input-wrapper {
    padding: 1.5rem;
}

.input-container {
    margin-bottom: 1rem;
}

.input-field {
    display: flex;
    align-items: flex-end;
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid var(--border-color);
    border-radius: 16px;
    padding: 1rem;
    gap: 1rem;
    transition: var(--transition-normal);
}

.input-field:focus-within {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 4px rgba(139, 92, 246, 0.1);
}

.input-field textarea {
    flex: 1;
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-size: 1rem;
    resize: none;
    max-height: 120px;
    font-family: inherit;
    line-height: 1.5;
}

.input-field textarea:focus {
    outline: none;
}

.input-field textarea::placeholder {
    color: var(--text-muted);
}

.input-actions {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.action-btn {
    width: 36px;
    height: 36px;
    border-radius: 8px;
    border: none;
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-muted);
    cursor: pointer;
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.action-btn:hover {
    background: rgba(255, 255, 255, 0.15);
    color: var(--text-secondary);
}

.send-btn-enhanced {
    width: 36px;
    height: 36px;
    border-radius: 8px;
    border: none;
    background: var(--gradient-accent);
    color: white;
    cursor: pointer;
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.send-btn-enhanced:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 12px rgba(139, 92, 246, 0.4);
}

/* Enhanced Input Footer */
.input-footer-enhanced {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.input-hints {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.hint-item {
    font-size: 0.75rem;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.hint-item kbd {
    padding: 0.1rem 0.3rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 4px;
    font-size: 0.7rem;
    border: 1px solid var(--border-color);
}

.chat-stats {
    display: flex;
    gap: 1rem;
}

.stat-item {
    font-size: 0.75rem;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.stat-item i {
    color: var(--accent-color);
}

/* Chat Quick Actions */
.chat-quick-actions {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 1.5rem;
    backdrop-filter: blur(10px);
}

.quick-actions-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.quick-actions-header h4 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.close-quick-actions {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.25rem;
    transition: var(--transition-fast);
}

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

.quick-actions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
}

.quick-action-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    cursor: pointer;
    transition: var(--transition-normal);
    text-align: center;
}

.quick-action-card:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: var(--accent-color);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(139, 92, 246, 0.2);
}

.quick-action-card i {
    font-size: 1.5rem;
    color: var(--accent-color);
}

.quick-action-card span {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
}

/* Responsive Design */
@media (max-width: 768px) {
    .chat-title-area h1 {
        font-size: 2rem;
    }
    
    .status-card {
        flex-direction: column;
        text-align: center;
        gap: 1rem;
    }
    
    .suggestion-categories {
        grid-template-columns: 1fr;
    }
    
    .input-footer-enhanced {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .quick-actions-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Summary + Chat Layout */
.summary-chat-header {
    background: rgba(255, 255, 255, 0.02);
    border-bottom: 1px solid var(--border-color);
    padding: 1.5rem 2rem;
    backdrop-filter: blur(10px);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1400px;
    margin: 0 auto;
    gap: 2rem;
}

.back-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-secondary);
    text-decoration: none;
    transition: var(--transition-fast);
    cursor: pointer;
    font-size: 0.9rem;
}

.back-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
    border-color: var(--accent-color);
}

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

.paper-info h2 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.paper-meta {
    display: flex;
    align-items: center;
    gap: 1rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.paper-meta .author {
    color: var(--accent-color);
}

.paper-meta .date,
.paper-meta .category {
    padding: 0.2rem 0.5rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 4px;
    font-size: 0.8rem;
}

.header-actions {
    display: flex;
    gap: 0.5rem;
}

.action-btn-header {
    width: 40px;
    height: 40px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

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

/* Summary + Chat Container */
.summary-chat-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    padding: 3rem;
    max-width: 1600px;
    margin: 0 auto;
    height: calc((var(--vh, 1vh) * 100) - 180px);
    min-height: 800px;
}

/* Summary Panel */
.summary-panel {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    overflow: hidden;
    backdrop-filter: blur(10px);
    display: flex;
    flex-direction: column;
}

.summary-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 2rem;
    border-bottom: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.02);
}

.summary-title {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.summary-title i {
    color: var(--accent-color);
    font-size: 1.25rem;
}

.summary-title h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.summary-actions {
    display: flex;
    gap: 0.5rem;
}

.summary-action-btn {
    width: 36px;
    height: 36px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

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

.summary-content {
    flex: 1;
    padding: 3rem;
    overflow-y: auto;
    font-size: 1.1rem;
    line-height: 1.8;
}

.summary-loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 200px;
    color: var(--text-secondary);
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid rgba(139, 92, 246, 0.3);
    border-top: 3px solid var(--accent-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.summary-text {
    color: var(--text-secondary);
    line-height: 1.9;
    font-size: 1.2rem;
}

.summary-text h1,
.summary-text h2,
.summary-text h3,
.summary-text h4 {
    color: var(--text-primary);
    margin: 2rem 0 1.5rem;
    font-size: 1.4rem;
    font-weight: 600;
}

.summary-text p {
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
    line-height: 1.8;
}

.summary-text ul,
.summary-text ol {
    margin: 1rem 0;
    padding-left: 1.5rem;
}

.summary-text li {
    margin-bottom: 0.5rem;
}

.summary-text strong {
    color: var(--text-primary);
}

.summary-stats {
    display: flex;
    justify-content: space-between;
    padding: 1rem 1.5rem;
    border-top: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.02);
}

.summary-stats .stat-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.summary-stats .stat-item i {
    color: var(--accent-color);
}

/* Chat Panel */
.chat-panel {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    overflow: hidden;
    backdrop-filter: blur(10px);
    display: flex;
    flex-direction: column;
}

.chat-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 2rem;
    border-bottom: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.02);
}

.chat-title {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.chat-title i {
    color: var(--accent-color);
    font-size: 1.25rem;
}

.chat-title h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.chat-status .status-indicator {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.85rem;
}

.chat-status .status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--success-color);
    animation: pulse 2s infinite;
}

.chat-messages-panel {
    flex: 1;
    padding: 2.5rem;
    overflow-y: auto;
    font-size: 1.1rem;
}

.chat-welcome {
    display: flex;
    gap: 1.5rem;
    padding: 2rem;
    background: rgba(139, 92, 246, 0.05);
    border: 1px solid rgba(139, 92, 246, 0.2);
    border-radius: 16px;
    margin-bottom: 2rem;
}

.welcome-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--gradient-accent);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.welcome-avatar i {
    color: white;
    font-size: 1.25rem;
}

.welcome-content h4 {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

.welcome-content p {
    color: var(--text-secondary);
    font-size: 1.05rem;
    line-height: 1.6;
    margin: 0;
}

.chat-input-panel {
    border-top: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.02);
    padding: 2.5rem;
}

.quick-questions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.quick-question-btn {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1.25rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 25px;
    color: var(--text-secondary);
    font-size: 0.95rem;
    cursor: pointer;
    transition: var(--transition-fast);
}

.quick-question-btn:hover {
    background: rgba(139, 92, 246, 0.1);
    border-color: var(--accent-color);
    color: var(--text-primary);
}

.quick-question-btn i {
    color: var(--accent-color);
    font-size: 0.7rem;
}

.chat-input-container {
    margin-top: 1rem;
}

.chat-input-field {
    display: flex;
    align-items: flex-end;
    gap: 1rem;
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid var(--border-color);
    border-radius: 16px;
    padding: 1.25rem;
    transition: var(--transition-normal);
}

.chat-input-field:focus-within {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 4px rgba(139, 92, 246, 0.1);
}

.chat-input-field textarea {
    flex: 1;
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-size: 1.1rem;
    resize: none;
    max-height: 150px;
    min-height: 50px;
    font-family: inherit;
    line-height: 1.6;
    padding: 0.5rem 0;
}

.chat-input-field textarea:focus {
    outline: none;
}

.chat-input-field textarea::placeholder {
    color: var(--text-muted);
}

.send-btn-panel {
    width: 44px;
    height: 44px;
    border-radius: 12px;
    border: none;
    background: var(--gradient-accent);
    color: white;
    cursor: pointer;
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    font-size: 1.1rem;
}

.send-btn-panel:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 12px rgba(139, 92, 246, 0.4);
}

/* Chat Messages in Panel */
.chat-message-panel {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    animation: messageSlideIn 0.3s ease-out;
}

.chat-message-panel.user {
    flex-direction: row-reverse;
}

.message-avatar-panel {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.message-avatar-panel.user {
    background: var(--gradient-primary);
}

.message-avatar-panel.bot {
    background: var(--gradient-accent);
}

.message-avatar-panel i {
    color: white;
    font-size: 0.9rem;
}

.message-content-panel {
    flex: 1;
    min-width: 0;
}

.message-content-panel.user {
    text-align: right;
}

.message-bubble {
    display: inline-block;
    padding: 1.1rem 1.6rem;
    border-radius: 18px;
    max-width: 95%;
    word-wrap: break-word;
    font-size: 1.1rem;
    line-height: 1.75;
    box-shadow: 0 6px 18px rgba(0,0,0,0.15);
}

.message-bubble.user {
    background: linear-gradient(135deg, rgba(124,58,237,0.18), rgba(168,85,247,0.18));
    border: none;
    color: var(--text-primary);
}

.message-bubble.bot {
    background: rgba(31, 41, 55, 0.6);
    border: none;
    color: #dbe3ee;
}

.message-time-panel {
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
}

/* Responsive Design */
@media (max-width: 1200px) {
    .summary-chat-container {
        grid-template-columns: 1fr;
        grid-template-rows: 1fr 1fr;
        height: auto;
        min-height: calc((var(--vh, 1vh) * 100) - 200px);
    }
    
    .header-content {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .paper-info h2 {
        white-space: normal;
        text-align: center;
    }
}

@media (max-width: 768px) {
    .summary-chat-container {
        padding: 1rem;
        gap: 1rem;
    }
    
    .summary-header,
    .chat-header { padding: 1rem; position: sticky; top: 70px; z-index: 5; }
    
    .summary-content {
        padding: 1rem;
        font-size: 1rem;
    }
    
    .chat-input-panel {
        padding: 1rem;
    }
    
    .chat-messages-panel {
        padding: 1rem;
        font-size: 1rem;
    }
    
    .quick-questions {
        flex-direction: column;
    }
    
    .quick-question-btn {
        justify-content: center;
        font-size: 0.9rem;
        padding: 0.6rem 1rem;
    }
    
    .summary-stats {
        flex-direction: column;
        gap: 0.75rem;
    }
    
    .summary-text {
        font-size: 1rem;
    }
    
    .summary-text h1,
    .summary-text h2,
    .summary-text h3,
    .summary-text h4 {
        font-size: 1.25rem;
    }
    
    .summary-text p {
        font-size: 1rem;
    }
    /* Make chat and summary panels occupy full height on mobile */
    #summary-tab .summary-panel,
    #chat-tab .chat-panel { height: calc((var(--vh, 1vh) * 100) - 180px); }
    #summary-tab .summary-content,
    #chat-tab .chat-messages-panel { height: calc((var(--vh, 1vh) * 100) - 300px); }
    .chat-input-panel { position: sticky; bottom: 0; background: rgba(15, 23, 42, 0.9); backdrop-filter: blur(10px); }
    .chat-input-field { padding: 1rem; }
    .chat-input-field textarea { min-height: 44px; }
}

/* Tab Navigation Styles */
.tab-navigation {
    background: rgba(255, 255, 255, 0.05);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    padding: 0 2rem;
    margin-bottom: 2rem;
}

.tab-nav-container {
    display: flex;
    gap: 0;
    max-width: 1200px;
    margin: 0 auto;
    overflow-x: auto;
    align-items: center;
}

.tab-btn {
    position: relative;
    background: none;
    border: none;
    color: #8b949e;
    padding: 1.5rem 2rem;
    white-space: nowrap;
}

/* view-toggle removed for strict tabs */

/* Chat Message Styles */
.chat-message {
    margin-bottom: 1.5rem;
    padding: 1rem;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.chat-message.user {
    background: rgba(124, 58, 237, 0.1);
    border-color: rgba(124, 58, 237, 0.2);
    margin-left: 2rem;
}

.chat-message.assistant {
    background: rgba(16, 185, 129, 0.1);
    border-color: rgba(16, 185, 129, 0.2);
    margin-right: 2rem;
}

.message-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 0.75rem;
}

.message-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.9rem;
}

.chat-message.user .message-avatar {
    background: linear-gradient(135deg, #7c3aed, #a855f7);
    color: white;
}

.chat-message.assistant .message-avatar {
    background: linear-gradient(135deg, #10b981, #06d6a0);
    color: white;
}

.message-info {
    display: flex;
    flex-direction: column;
    gap: 0.125rem;
}

.message-sender {
    color: #ffffff;
    font-weight: 500;
    font-size: 0.9rem;
}

.message-time {
    color: #6b7280;
    font-size: 0.75rem;
}

.message-content {
    color: #e6edf3;
    line-height: 1.6;
}

.message-content p {
    margin: 0;
}

/* Typing Indicator */
.typing-indicator {
    margin-bottom: 1.5rem;
    padding: 1rem;
    border-radius: 12px;
    background: rgba(16, 185, 129, 0.1);
    border: 1px solid rgba(16, 185, 129, 0.2);
    margin-right: 2rem;
}

.typing-dots {
    display: flex;
    gap: 0.25rem;
    align-items: center;
    padding: 0.5rem 0;
}

.typing-dots .dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: #10b981;
    animation: typingAnimation 1.4s infinite ease-in-out;
}

.typing-dots .dot:nth-child(1) {
    animation-delay: 0s;
}

.typing-dots .dot:nth-child(2) {
    animation-delay: 0.2s;
}

.typing-dots .dot:nth-child(3) {
    animation-delay: 0.4s;
}

@keyframes typingAnimation {
    0%, 60%, 100% {
        transform: scale(1);
        opacity: 0.5;
    }
    30% {
        transform: scale(1.2);
        opacity: 1;
    }
}

/* Enhanced Summary Tab Styles */
.summary-container {
    background: transparent;
    border: none;
}

.summary-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    padding: 1.5rem 2rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    background: rgba(255, 255, 255, 0.03);
    border-top-left-radius: 16px;
    border-top-right-radius: 16px;
}

.summary-title {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.summary-icon {
    background: linear-gradient(135deg, #7c3aed, #a855f7);
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.summary-icon i {
    font-size: 1.5rem;
    color: white;
}

.summary-title-text h3 {
    color: #ffffff;
    font-size: 1.5rem;
    font-weight: 600;
    margin: 0 0 0.25rem 0;
}

.summary-title-text p {
    color: #8b949e;
    margin: 0;
    font-size: 0.95rem;
}

.summary-actions {
    display: flex;
    gap: 0.75rem;
}

.summary-action-btn {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: #ffffff;
    padding: 0.75rem 1rem;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.summary-action-btn:hover {
    background: rgba(124, 58, 237, 0.3);
    border-color: rgba(124, 58, 237, 0.5);
    transform: translateY(-1px);
}

.summary-body {
    display: grid;
    grid-template-columns: minmax(0, 2fr) minmax(0, 1fr);
    gap: 0;
}

@media (max-width: 992px) {
    .summary-body {
        grid-template-columns: 1fr;
    }
}

.summary-main-content {
    min-width: 0;
    padding: 2rem;
}

.summary-content {
    height: 65vh;
    max-height: 700px;
    overflow-y: auto;
    padding-right: 1.5rem;
}

.summary-content::-webkit-scrollbar {
    width: 6px;
}
.summary-content::-webkit-scrollbar-track {
    background: rgba(0, 0, 0, 0.2);
    border-radius: 3px;
}
.summary-content::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 3px;
}

.summary-loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    gap: 1rem;
}

.summary-text {
    color: #cdd5e0;
    line-height: 1.8;
    font-size: 1.05rem;
}

.summary-text h3 {
    font-size: 1.25rem;
    color: #fff;
    font-weight: 600;
    margin-top: 2rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}
.summary-text p {
    margin-bottom: 1rem;
}

.summary-sidebar {
    display: flex;
    flex-direction: column;
    gap: 2rem;
    padding: 2rem;
    border-left: 1px solid rgba(255, 255, 255, 0.1);
    background: rgba(255, 255, 255, 0.02);
}

.summary-stats, .summary-keywords {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    padding: 1.5rem;
}

.summary-stats h4, .summary-keywords h4 {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.1rem;
    font-weight: 600;
    margin: 0 0 1rem 0;
    color: #fff;
    padding-bottom: 1rem;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.stats-list {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.stat-item {
    background: rgba(0,0,0,0.2);
    border-radius: 12px;
    padding: 1.25rem;
    position: relative;
    overflow: hidden;
    transition: all 0.2s ease-in-out;
    border: 1px solid transparent;
}

.stat-item:hover {
    transform: translateY(-2px);
    background: rgba(0,0,0,0.3);
    border-color: rgba(124, 58, 237, 0.5);
}

.stat-text {
    position: relative;
    z-index: 2;
}

.stat-label {
    font-size: 0.8rem;
    color: #8b949e;
    margin-bottom: 0.25rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.stat-value {
    font-size: 1.6rem;
    font-weight: 700;
    color: #fff;
}

.stat-icon-small {
    display: none;
}

.stat-item::after {
    font-family: "Font Awesome 6 Free";
    font-weight: 900;
    position: absolute;
    right: 1rem;
    top: 50%;
    transform: translateY(-50%);
    font-size: 2.5rem;
    color: rgba(124, 58, 237, 0.15);
    z-index: 1;
    transition: all 0.3s ease;
}

.stat-item:hover::after {
    color: rgba(124, 58, 237, 0.3);
    transform: translateY(-50%) scale(1.1);
}

#readingTime-item::after { content: '\f017'; }
#wordCount-item::after { content: '\f15c'; }
#compressionRatio-item::after { content: '\f78c'; }
#keyPoints-item::after { content: '\f005'; }

.keywords-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.keyword-chip {
    background: rgba(255, 255, 255, 0.1);
    color: #cdd5e0;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.keyword-chip:hover {
    background: #7c3aed;
    color: #fff;
    transform: translateY(-1px);
}

.keyword-chip.skeleton {
    background: rgba(255, 255, 255, 0.1);
    width: 80px;
    height: 33px;
    border-radius: 20px;
    animation: pulse-bg 1.5s infinite;
}

@keyframes pulse-bg {
    0%, 100% {
        background-color: rgba(255, 255, 255, 0.1);
    }
    50% {
        background-color: rgba(255, 255, 255, 0.15);
    }
}

.mobile-nav-toggle {
    display: none;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.5rem 0.75rem;
    border-radius: 10px;
}

@media (max-width: 992px) {
    .mobile-nav-toggle { display: inline-flex; align-items: center; justify-content: center; }
    .landing-nav-links, .nav-links {
        position: absolute;
        top: 70px;
        right: 0;
        left: 0;
        display: none;
        flex-direction: column;
        gap: 0.5rem;
        background: rgba(15, 23, 42, 0.98);
        border-bottom: 1px solid var(--border-color);
        padding: 0.75rem 1rem 1rem;
    }
    .landing-nav-links.show, .nav-links.show { display: flex; }
}

@media (max-width: 480px) {
    .toast-container { right: 50%; transform: translateX(50%); }
}

/* Show only active tab content */
.tab-content { display: none; }
.tab-content.active { display: block; }

/* Chat Container sizing overrides for better viewport fit */
#chat-tab .chat-container {
    height: calc((var(--vh, 1vh) * 100) - 180px);
    max-height: none;
}

/* Reduce header/input paddings to save vertical space */
#chat-tab .chat-header { padding: 1rem 1.25rem; }
#chat-tab .chat-messages-container { padding: 1.25rem; }
#chat-tab .chat-input-area { padding: 0.75rem 1.0rem 1rem; position: sticky; bottom: 0; background: rgba(15,23,42,0.9); backdrop-filter: blur(8px); }

/* Make quick chips compact and horizontally scrollable */
#chat-tab .quick-questions-chips {
    margin-bottom: 0.5rem;
    gap: 0.4rem;
    overflow-x: auto;
    white-space: nowrap;
}
#chat-tab .quick-questions-chips::-webkit-scrollbar { height: 6px; }

/* Slightly tighter spacing between messages */
.chat-message-panel { margin-bottom: 1rem; }

/* Slightly smaller bubble text to fit one exchange */
.message-bubble { font-size: 1rem; line-height: 1.6; }

@media (max-width: 768px) {
    #chat-tab .chat-messages-container { padding: 0.75rem; }
    .chat-message-panel { margin-bottom: 0.75rem; }
    .message-bubble { font-size: 0.95rem; line-height: 1.55; }
}

/* Global mobile improvements */
@media (max-width: 480px) {
	/* Navbar */
	.nav-container { height: 56px; padding: 0 0.75rem; }
	.brand-icon { width: 32px; height: 32px; }
	.brand-name { font-size: 1rem; }
	.brand-tagline { display: none; }
	.mobile-nav-toggle { padding: 0.4rem 0.6rem; }

	/* Layout paddings */
	.main-container { padding: 0.75rem; }
	.section { padding-left: 0; padding-right: 0; }

	/* Hero */
	.hero { padding: 3.5rem 0 2rem; }
	.hero-title { font-size: 2rem; }
	.hero-subtitle { font-size: 1rem; padding: 0 0.25rem; }
	.hero-cta { gap: 0.5rem; }
	.cta-button { width: 100%; min-width: auto; padding: 0.75rem 1rem; }

	/* Cards */
	.feature-card, .quick-search-card, .upload-method-card { padding: 1rem; border-radius: 12px; }
	.paper-card, .result-card { padding: 1rem; border-radius: 12px; }

	/* Search */
	.search-hero-content { padding: 0 1rem; }
	.search-input-wrapper { padding: 0.5rem 1rem; border-radius: 14px; }
	.search-submit-btn { padding: 0.6rem 0.9rem; border-radius: 10px; }
	.search-actions { gap: 0.35rem; }
	.voice-search-btn, .advanced-search-btn { width: 42px; height: 42px; border-radius: 10px; }

	/* Tabs & headers */
	.tab-navigation { padding: 0 1rem; }
	.tab-btn { padding: 0.9rem 1rem; }
	.summary-header, .chat-header { padding: 1rem; }
	.summary-content { padding: 1rem; }

	/* Summary + Chat sticky alignment */
	.summary-header, .chat-header { position: sticky; top: 56px; z-index: 5; }

	/* Chat */
	#chat-tab .chat-messages-container { padding: 0.75rem; }
	.quick-questions-chips { gap: 0.4rem; }
	.message-bubble { font-size: 0.97rem; line-height: 1.55; }
}

@media (max-width: 360px) {
	.nav-container { padding: 0 0.5rem; }
	.hero-title { font-size: 1.75rem; }
	.search-input-wrapper input { font-size: 1rem; }
	.tab-btn { padding: 0.75rem 0.85rem; }
	.message-bubble { font-size: 0.92rem; }
}

/* My Papers mobile responsiveness */
@media (max-width: 768px) {
	.mypapers-hero { padding: 2rem 0 1.5rem; }
	.mypapers-hero h1 { font-size: 2rem; }
	.mypapers-hero p { font-size: 1rem; }
	.mypapers-actions { flex-direction: column; gap: 0.75rem; }
	.refresh-papers-btn, .clear-all-btn { width: 100%; }
	.papers-grid { grid-template-columns: 1fr; gap: 1rem; padding: 1rem 0; }
	.paper-card-mypapers { padding: 1rem; }
	.paper-card-actions { flex-direction: column; gap: 0.5rem; }
	.paper-action-btn { width: 100%; }
}

@media (max-width: 480px) {
	.mypapers-hero { padding: 1.5rem 0 1rem; }
	.mypapers-hero h1 { font-size: 1.75rem; }
	.mypapers-icon-large { width: 60px; height: 60px; font-size: 1.5rem; }
	.paper-card-mypapers { padding: 0.75rem; }
	.paper-card-title { font-size: 1rem; }
	.paper-card-meta { font-size: 0.8rem; }
	.paper-action-btn { padding: 0.5rem 0.75rem; font-size: 0.8rem; }
}