* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Enhanced Color Palette */
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
    --secondary-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --accent-gradient: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
    --warm-gradient: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
    
    /* Status Colors */
    --success-color: #10b981;
    --success-gradient: linear-gradient(135deg, #10b981 0%, #059669 100%);
    --error-color: #ef4444;
    --error-gradient: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
    --warning-color: #f59e0b;
    --warning-gradient: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
    
    /* Text Colors */
    --text-primary: #1e293b;
    --text-secondary: #333;
    --text-tertiary: #94a3b8;
    --text-white: #ffffff;
    
    /* Background Colors */
    --background-primary: #ffffff;
    --background-secondary: #f8fafc;
    --background-tertiary: #f1f5f9;
    --background-glass: rgba(255, 255, 255, 0.25);
    --background-glass-dark: rgba(255, 255, 255, 0.1);
    
    /* Border Colors */
    --border-light: #e2e8f0;
    --border-medium: #cbd5e1;
    --border-dark: #94a3b8;
    
    /* Shadow System */
    --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --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-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    --shadow-glow: 0 0 20px rgba(102, 126, 234, 0.3);
    --shadow-glow-success: 0 0 20px rgba(16, 185, 129, 0.3);
    --shadow-glow-error: 0 0 20px rgba(239, 68, 68, 0.3);
    
    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-2xl: 32px;
    --radius-full: 9999px;
    
    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    
    /* Transitions */
    --transition-fast: 0.15s ease-out;
    --transition-normal: 0.3s ease-out;
    --transition-slow: 0.5s ease-out;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--primary-gradient);
    background-attachment: fixed;
    min-height: 100vh;
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(circle at 20% 80%, rgba(120, 119, 198, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(255, 119, 198, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(120, 219, 255, 0.2) 0%, transparent 50%);
    pointer-events: none;
    z-index: -1;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--space-xl);
    position: relative;
    z-index: 1;
}

.header {
    text-align: center;
    margin-bottom: var(--space-3xl);
    color: var(--text-white);
    position: relative;
}

.header::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 200px;
    height: 200px;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
    border-radius: 50%;
    z-index: -1;
    animation: headerGlow 4s ease-in-out infinite alternate;
}

@keyframes headerGlow {
    0% { transform: translate(-50%, -50%) scale(1); opacity: 0.5; }
    100% { transform: translate(-50%, -50%) scale(1.2); opacity: 0.8; }
}

.header h1 {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 800;
    margin-bottom: var(--space-md);
    text-shadow: 0 4px 20px rgba(0,0,0,0.3);
    background: linear-gradient(135deg, #ffffff 0%, #f0f9ff 50%, #e0f2fe 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: titleShine 3s ease-in-out infinite;
    letter-spacing: -0.02em;
}

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

.header p {
    font-size: 1.3rem;
    opacity: 0.95;
    max-width: 700px;
    margin: 0 auto;
    font-weight: 400;
    text-shadow: 0 2px 10px rgba(0,0,0,0.2);
    line-height: 1.5;
}

.compatibility-warning {
    background: var(--warning-gradient);
    color: var(--text-white);
    padding: var(--space-lg) var(--space-xl);
    border-radius: var(--radius-lg);
    margin-bottom: var(--space-xl);
    text-align: center;
    font-weight: 600;
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    border: 1px solid rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    position: relative;
    overflow: hidden;
}

.compatibility-warning::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    animation: warningShimmer 3s infinite;
}

@keyframes warningShimmer {
    0% { left: -100%; }
    100% { left: 100%; }
}

.compatibility-warning.hidden {
    display: none;
}

.main-card {
    background: var(--background-glass);
    border-radius: var(--radius-2xl);
    padding: var(--space-2xl) var(--space-xl);
    box-shadow: var(--shadow-2xl);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    position: relative;
    overflow: hidden;
    animation: cardFadeIn 0.8s ease-out;
}

@keyframes cardFadeIn {
    0% { 
        opacity: 0; 
        transform: translateY(40px) scale(0.95); 
    }
    100% { 
        opacity: 1; 
        transform: translateY(0) scale(1); 
    }
}

.main-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.8), transparent);
}

.main-card::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: conic-gradient(from 0deg, transparent, rgba(255,255,255,0.05), transparent);
    animation: cardRotate 20s linear infinite;
    z-index: -1;
}

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

.settings-section {
    border-bottom: 2px solid var(--border-color);
}

.settings-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-bottom: 1.5rem;
}

.setting-group {
    display: flex;
    flex-direction: column;
}

.setting-group label {
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.setting-group input, .setting-group select {
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    font-size: 1rem;
    transition: all 0.2s ease;
    background: white;
}

.setting-group input:focus, .setting-group select:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.quality-info {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
    padding: 0.75rem;
    background: var(--background-light);
    border-radius: 8px;
    border-left: 4px solid #667eea;
}

.advanced-settings {
    background: var(--background-light);
    padding: 1.5rem;
    border-radius: 12px;
    margin-top: 1rem;
}

.advanced-toggle {
    background: none;
    border: none;
    color: #333;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
    transition: color 0.2s;
}

.advanced-toggle:hover {
    color: #5a67d8;
}

.advanced-content {
    display: none;
}

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

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

.upload-area {
    border: 3px dashed var(--border-medium);
    border-radius: var(--radius-xl);
    padding: var(--space-3xl) var(--space-xl);
    text-align: center;
    transition: var(--transition-normal);
    cursor: pointer;
    background: var(--background-glass-dark);
    backdrop-filter: blur(10px);
    margin-bottom: var(--space-xl);
    position: relative;
    overflow: hidden;
    min-height: 280px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.upload-area::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(102, 126, 234, 0.15), transparent);
    transition: var(--transition-slow);
}

.upload-area::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 120px;
    height: 120px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(102, 126, 234, 0.1) 0%, transparent 70%);
    opacity: 0;
    transition: var(--transition-normal);
    z-index: -1;
}

.upload-area:hover::before {
    left: 100%;
}

.upload-area:hover::after {
    opacity: 1;
    transform: translate(-50%, -50%) scale(1.2);
}

.upload-area:hover, .upload-area.dragover {
    border-color: #667eea;
    background: var(--background-glass);
    transform: translateY(-4px) scale(1.02);
    box-shadow: var(--shadow-xl), var(--shadow-glow);
}

.upload-area.dragover {
    border-style: solid;
    animation: dragPulse 0.8s ease-in-out infinite alternate;
}

@keyframes dragPulse {
    0% { transform: translateY(-4px) scale(1.02); }
    100% { transform: translateY(-2px) scale(1.05); }
}

.upload-area.processing {
    pointer-events: none;
    opacity: 0.6;
    animation: processingPulse 2s ease-in-out infinite;
}

@keyframes processingPulse {
    0%, 100% { opacity: 0.6; }
    50% { opacity: 0.8; }
}

.upload-icon {
    font-size: 5rem;
    margin-bottom: var(--space-lg);
    color: var(--text-tertiary);
    transition: var(--transition-normal);
    filter: drop-shadow(0 4px 8px rgba(0,0,0,0.1));
}

.upload-area:hover .upload-icon {
    transform: scale(1.15) rotateY(20deg);
    color: #667eea;
}

.upload-text {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
    color: var(--text-primary);
    text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.upload-subtext {
    color: var(--text-secondary);
    margin-bottom: var(--space-md);
    font-size: 1.1rem;
    font-weight: 500;
}

.supported-formats {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--space-sm);
    margin-top: var(--space-lg);
}

.format-tag {
    background: var(--background-primary);
    border: 2px solid var(--border-light);
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-full);
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-primary);
    transition: var(--transition-fast);
    backdrop-filter: blur(5px);
    position: relative;
    overflow: hidden;
}

.format-tag::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(102, 126, 234, 0.1), transparent);
    transition: var(--transition-normal);
}

.format-tag:hover::before {
    left: 100%;
}

.format-tag:hover {
    border-color: #667eea;
    background: var(--background-glass);
    transform: translateY(-2px) scale(1.05);
    box-shadow: var(--shadow-md);
    color: #667eea;
}

.file-input {
    display: none;
}

.file-list {
    margin-bottom: 2rem;
}

.file-item {
    display: grid;
    grid-template-columns: auto 1fr auto auto auto;
    align-items: center;
    padding: var(--space-lg);
    background: var(--background-glass);
    backdrop-filter: blur(15px);
    border-radius: var(--radius-lg);
    margin-bottom: var(--space-md);
    border: 2px solid var(--border-light);
    gap: var(--space-lg);
    transition: var(--transition-normal);
    position: relative;
    overflow: hidden;
    animation: fileItemSlide 0.4s ease-out;
}

@keyframes fileItemSlide {
    0% {
        opacity: 0;
        transform: translateX(-20px);
    }
    100% {
        opacity: 1;
        transform: translateX(0);
    }
}

.file-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: transparent;
    transition: var(--transition-normal);
}

.file-item:hover {
    border-color: #667eea;
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px) scale(1.01);
}

.file-item:hover::before {
    background: var(--primary-gradient);
}

.file-item.processing {
    border-color: var(--warning-color);
    background: var(--background-glass);
    animation: processingGlow 2s ease-in-out infinite;
}

.file-item.processing::before {
    background: var(--warning-gradient);
}

@keyframes processingGlow {
    0%, 100% { box-shadow: var(--shadow-md); }
    50% { box-shadow: var(--shadow-lg), 0 0 20px rgba(245, 158, 11, 0.3); }
}

.file-item.completed {
    border-color: var(--success-color);
    background: var(--background-glass);
}

.file-item.completed::before {
    background: var(--success-gradient);
}

.file-item.error {
    border-color: var(--error-color);
    background: var(--background-glass);
}

.file-item.error::before {
    background: var(--error-gradient);
}

.file-icon {
    font-size: 1.75rem;
    color: #667eea;
}

.file-info {
    min-width: 0;
}

.file-name {
    font-weight: 600;
    color: var(--text-primary);
    word-break: break-word;
    margin-bottom: 0.25rem;
}

.file-details {
    display: flex;
    gap: 1rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
    flex-wrap: wrap;
}

.compression-info {
    background: var(--success-color);
    color: white;
    padding: 0.125rem 0.5rem;
    border-radius: 12px;
    font-weight: 600;
    font-size: 0.75rem;
}

.file-progress {
    min-width: 120px;
}

.progress-bar {
    width: 100%;
    height: 12px;
    background: var(--border-light);
    border-radius: var(--radius-sm);
    overflow: hidden;
    margin-bottom: var(--space-xs);
    position: relative;
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.1);
}

.progress-bar::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(90deg, 
        rgba(255,255,255,0.2) 25%, 
        transparent 50%, 
        rgba(255,255,255,0.2) 75%);
    animation: progressShimmer 2s infinite;
}

@keyframes progressShimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.progress-fill {
    height: 100%;
    background: var(--primary-gradient);
    border-radius: var(--radius-sm);
    transition: var(--transition-normal);
    width: 0%;
    position: relative;
    overflow: hidden;
}

.progress-fill::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(45deg, 
        transparent 25%, 
        rgba(255,255,255,0.3) 50%, 
        transparent 75%);
    animation: progressGlow 2s infinite;
}

@keyframes progressGlow {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.progress-text {
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-align: center;
}

.file-status {
    font-size: 0.875rem;
    font-weight: 600;
    min-width: 100px;
    text-align: center;
    padding: 0.375rem 0.75rem;
    border-radius: 20px;
    transition: all 0.2s;
}

.status-pending {
    background: #f3f4f6;
    color: var(--text-secondary);
}

.status-processing {
    background: #fef3c7;
    color: #92400e;
}

.status-completed {
    background: #d1fae5;
    color: #065f46;
}

.status-error {
    background: #fee2e2;
    color: #991b1b;
}

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

.file-action-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 1.25rem;
    padding: 0.5rem;
    border-radius: 6px;
    transition: all 0.2s;
}

.file-action-btn:hover {
    background: var(--border-color);
}

.file-action-btn.retry {
    color: var(--warning-color);
}

.file-action-btn.remove {
    color: var(--error-color);
}

.file-action-btn:hover.retry {
    background: #fef3c7;
}

.file-action-btn:hover.remove {
    background: #fee2e2;
}

.action-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 2rem;
    flex-wrap: wrap;
}

.btn {
    padding: var(--space-lg) var(--space-xl);
    border: none;
    border-radius: var(--radius-lg);
    font-size: 1.1rem;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition-normal);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    position: relative;
    overflow: hidden;
    min-width: 160px;
    justify-content: center;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    backdrop-filter: blur(10px);
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
    transition: var(--transition-slow);
}

.btn::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 0;
    height: 0;
    background: rgba(255,255,255,0.2);
    border-radius: 50%;
    transition: var(--transition-normal);
}

.btn:hover::before {
    left: 100%;
}

.btn:active::after {
    width: 100%;
    height: 100%;
}

.btn-primary {
    background: var(--primary-gradient);
    color: var(--text-white);
    box-shadow: var(--shadow-lg);
    border: 1px solid rgba(255,255,255,0.2);
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-4px) scale(1.02);
    box-shadow: var(--shadow-xl), var(--shadow-glow);
}

.btn-secondary {
    background: var(--background-glass);
    color: var(--text-primary);
    border: 2px solid var(--border-medium);
    backdrop-filter: blur(15px);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--background-glass-dark);
    border-color: #667eea;
    color: #667eea;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-success {
    background: var(--success-gradient);
    color: var(--text-white);
    border: 1px solid rgba(255,255,255,0.2);
    box-shadow: var(--shadow-lg);
}

.btn-success:hover:not(:disabled) {
    transform: translateY(-4px) scale(1.02);
    box-shadow: var(--shadow-xl), var(--shadow-glow-success);
}

.btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    transform: none !important;
    box-shadow: none !important;
}

.overall-progress {
    margin: var(--space-xl) 0;
    padding: var(--space-2xl);
    background: var(--background-glass);
    backdrop-filter: blur(20px);
    border-radius: var(--radius-xl);
    border: 2px solid rgba(102, 126, 234, 0.3);
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-xl), inset 0 1px 0 rgba(255,255,255,0.3);
}

.overall-progress::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.4), transparent);
    animation: overallShimmer 3s infinite;
}

.overall-progress::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: conic-gradient(from 0deg, transparent, rgba(102, 126, 234, 0.1), transparent);
    animation: overallRotate 15s linear infinite;
    z-index: -1;
}

@keyframes overallShimmer {
    0% { left: -100%; }
    100% { left: 100%; }
}

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

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

.overall-progress-text {
    font-weight: 700;
    color: var(--text-primary);
    font-size: 1.125rem;
}

.overall-progress-stats {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.overall-progress-bar {
    width: 100%;
    height: 16px;
    background: white;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.1);
}

.overall-progress-fill {
    height: 100%;
    background: var(--primary-gradient);
    border-radius: 8px;
    transition: width 0.5s ease;
    width: 0%;
    position: relative;
}

.overall-progress-fill::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(45deg, transparent 30%, rgba(255,255,255,0.3) 50%, transparent 70%);
    animation: progressShine 2s infinite;
}

@keyframes progressShine {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.hidden {
    display: none !important;
}

.notification {
    position: fixed;
    top: 2rem;
    right: 2rem;
    padding: 1rem 1.5rem;
    border-radius: 12px;
    color: white;
    font-weight: 600;
    z-index: 1000;
    transform: translateX(100%);
    transition: transform 0.3s ease;
    box-shadow: var(--shadow-large);
}

.notification.show {
    transform: translateX(0);
}

.notification.success {
    background: var(--success-color);
}

.notification.error {
    background: var(--error-color);
}

.notification.warning {
    background: var(--warning-color);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: var(--space-lg);
    margin-bottom: var(--space-xl);
}

.stat-card {
    background: var(--background-glass);
    backdrop-filter: blur(15px);
    padding: var(--space-xl);
    border-radius: var(--radius-lg);
    border: 2px solid var(--border-light);
    text-align: center;
    transition: var(--transition-normal);
    position: relative;
    overflow: hidden;
    animation: statCardFloat 0.6s ease-out;
}

@keyframes statCardFloat {
    0% {
        opacity: 0;
        transform: translateY(20px) scale(0.9);
    }
    100% {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--secondary-gradient);
    transform: scaleX(0);
    transition: var(--transition-normal);
}

.stat-card:hover {
    border-color: #667eea;
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px) scale(1.02);
}

.stat-card:hover::before {
    transform: scaleX(1);
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 800;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--space-sm);
    line-height: 1;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Enhanced Mobile Responsiveness */
@media (max-width: 768px) {
    body::before {
        background-image: 
            radial-gradient(circle at 50% 20%, rgba(120, 119, 198, 0.4) 0%, transparent 60%),
            radial-gradient(circle at 80% 80%, rgba(255, 119, 198, 0.3) 0%, transparent 60%);
    }

    .container {
        padding: var(--space-md);
    }

    .header h1 {
        font-size: clamp(2rem, 8vw, 3rem);
    }

    .header p {
        font-size: 1.1rem;
    }

    .main-card {
        padding: var(--space-xl) var(--space-md);
        border-radius: var(--radius-xl);
    }

    .settings-grid {
        grid-template-columns: 1fr;
        gap: var(--space-md);
    }

    .upload-area {
        padding: var(--space-2xl) var(--space-md);
        min-height: 220px;
    }

    .upload-icon {
        font-size: 4rem;
    }

    .upload-text {
        font-size: 1.3rem;
    }

    .upload-subtext {
        font-size: 1rem;
    }

    .file-item {
        grid-template-columns: auto 1fr;
        gap: var(--space-md);
        padding: var(--space-md);
    }

    .file-progress, .file-status, .file-actions {
        grid-column: 1 / -1;
        margin-top: var(--space-sm);
    }

    .file-progress {
        order: 1;
    }

    .file-status {
        order: 2;
        text-align: left;
    }

    .file-actions {
        order: 3;
        justify-self: end;
    }

    .action-buttons {
        flex-direction: column;
        gap: var(--space-md);
    }

    .btn {
        min-width: 100%;
        padding: var(--space-md) var(--space-lg);
    }

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

    .stat-card {
        padding: var(--space-lg);
    }

    .stat-value {
        font-size: 2rem;
    }

    .overall-progress {
        padding: var(--space-lg);
        margin: var(--space-lg) 0;
    }

    .notification {
        top: var(--space-md);
        right: var(--space-md);
        left: var(--space-md);
        font-size: 0.9rem;
    }

    .format-tag {
        font-size: 0.75rem;
        padding: var(--space-xs) var(--space-sm);
    }
}

@media (max-width: 480px) {
    .stats-grid {
        grid-template-columns: 1fr;
    }

    .upload-area {
        padding: var(--space-xl) var(--space-sm);
    }

    .supported-formats {
        gap: var(--space-xs);
    }

    .format-tag {
        font-size: 0.7rem;
    }
}

/* Enhanced Loading States */
.loading-spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    border-top-color: var(--text-white);
    animation: spin 1s ease-in-out infinite;
}

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

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

::-webkit-scrollbar-track {
    background: var(--background-secondary);
    border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb {
    background: var(--primary-gradient);
    border-radius: var(--radius-sm);
    border: 2px solid var(--background-secondary);
}

::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(135deg, #5a67d8 0%, #667eea 100%);
}

/* Focus States for Accessibility */
.btn:focus,
.setting-group input:focus,
.setting-group select:focus {
    outline: 3px solid rgba(102, 126, 234, 0.3);
    outline-offset: 2px;
}

/* Print Styles */
@media print {
    body::before,
    .main-card::after,
    .overall-progress::after {
        display: none;
    }

    .main-card {
        box-shadow: none;
        border: 1px solid var(--border-medium);
    }
}

.loading-spinner {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s ease-in-out infinite;
}

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