/* ======================
   ADVANCED FILE CONVERTER STYLES
   Modern, Professional Design with Animations
   ====================== */

:root {
    /* Primary Colors */
    --primary-color: #667eea;
    --primary-dark: #5a67d8;
    --primary-light: #764ba2;
    
    /* Secondary Colors */
    --secondary-color: #f093fb;
    --accent-color: #4facfe;
    --success-color: #48bb78;
    --warning-color: #ed8936;
    --error-color: #f56565;
    
    /* Neutral Colors */
    --white: #ffffff;
    --gray-50: #f9fafb;
    --gray-100: #f7fafc;
    --gray-200: #edf2f7;
    --gray-300: #e2e8f0;
    --gray-400: #cbd5e0;
    --gray-500: #a0aec0;
    --gray-600: #718096;
    --gray-700: #4a5568;
    --gray-800: #2d3748;
    --gray-900: #1a202c;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    --gradient-secondary: linear-gradient(135deg, var(--accent-color) 0%, var(--primary-color) 100%);
    --gradient-success: linear-gradient(135deg, #48bb78 0%, #38a169 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);
    
    /* Transitions */
    --transition-fast: all 0.15s ease;
    --transition-normal: all 0.3s ease;
    --transition-slow: all 0.5s ease;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--gray-800);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    font-size: 14px;
}
/* ======================
   LAYOUT & CONTAINER
   ====================== */

.tool-page {
    padding: var(--spacing-xl) var(--spacing-md);
    min-height: 100vh;
}

.tool-container {
    max-width: 1400px;
    margin: 0 auto;
    background: var(--white);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.header-section {
    background: var(--gradient-primary);
    padding: var(--spacing-2xl) var(--spacing-xl);
    text-align: center;
    color: var(--white);
    position: relative;
    overflow: hidden;
}

.header-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>') repeat;
    opacity: 0.3;
}

.header-section h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    position: relative;
    z-index: 1;
}

.header-section h1 i {
    margin-right: var(--spacing-md);
    font-size: 2.2rem;
    vertical-align: middle;
}

.tool-description {
    position: relative;
    z-index: 1;
}

.tool-description p {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-xl);
    opacity: 0.95;
    line-height: 1.7;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.feature-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.15);
    border-radius: var(--radius-lg);
    backdrop-filter: blur(5px);
    transition: var(--transition-normal);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.feature-item:hover {
    background: rgba(255, 255, 255, 0.25);
    transform: translateY(-2px);
}

.feature-item i {
    font-size: 1.2rem;
    opacity: 0.9;
}

.feature-item span {
    font-weight: 500;
    font-size: 0.95rem;
}

.tool-interface {
    padding: var(--spacing-2xl);
    background: var(--gray-50);
}

/* ======================
   UPLOAD SECTION
   ====================== */

.upload-section {
    margin-bottom: var(--spacing-2xl);
}

.upload-area {
    background: var(--white);
    border: 3px dashed var(--gray-300);
    border-radius: var(--radius-2xl);
    padding: var(--spacing-2xl);
    text-align: center;
    transition: var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.upload-area:hover,
.upload-area.dragover {
    border-color: var(--primary-color);
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.05) 0%, rgba(249, 147, 251, 0.05) 100%);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.upload-area::before {
    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: rotate 8s linear infinite;
    opacity: 0;
    transition: var(--transition-normal);
}

.upload-area:hover::before {
    opacity: 1;
}

.upload-content {
    position: relative;
    z-index: 1;
}

.upload-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    border-radius: 50%;
    box-shadow: var(--shadow-lg);
    animation: float 3s ease-in-out infinite;
}

.upload-icon i {
    font-size: 2.5rem;
    color: var(--white);
}

.upload-content h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: var(--spacing-sm);
}

.upload-content p {
    color: var(--gray-600);
    margin-bottom: var(--spacing-lg);
    font-size: 1.1rem;
}

.upload-btn {
    background: var(--gradient-secondary);
    color: var(--white);
    border: none;
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: var(--radius-lg);
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: var(--transition-normal);
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    box-shadow: var(--shadow-md);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.upload-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl);
}

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

.supported-formats {
    margin-top: var(--spacing-lg);
    padding: var(--spacing-md);
    background: var(--gray-100);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--primary-color);
}

.supported-formats p {
    color: var(--gray-700);
    font-size: 0.9rem;
    margin: 0;
}

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

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* ======================
   FILES SECTION
   ====================== */

.files-section {
    margin-bottom: var(--spacing-2xl);
    background: var(--white);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--gray-200);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--gray-200);
}

.section-header h3 {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--gray-800);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.section-header h3 i {
    color: var(--primary-color);
}

.file-stats {
    display: flex;
    gap: var(--spacing-md);
    font-size: 0.9rem;
    color: var(--gray-600);
    font-weight: 500;
}

.files-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    min-height: 120px;
}

.file-item {
    background: var(--gray-50);
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    transition: var(--transition-normal);
    position: relative;
    overflow: hidden;
}

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

.file-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
    font-size: 1.5rem;
    flex-shrink: 0;
}

.file-icon.image { background: linear-gradient(135deg, #ff6b6b, #ffa726); color: white; }
.file-icon.document { background: linear-gradient(135deg, #4fc3f7, #29b6f6); color: white; }
.file-icon.audio { background: linear-gradient(135deg, #ab47bc, #8e24aa); color: white; }
.file-icon.video { background: linear-gradient(135deg, #66bb6a, #43a047); color: white; }
.file-icon.default { background: linear-gradient(135deg, #78909c, #607d8b); color: white; }

.file-details {
    flex: 1;
    min-width: 0;
}

.file-name {
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: var(--spacing-xs);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.file-meta {
    display: flex;
    gap: var(--spacing-md);
    font-size: 0.85rem;
    color: var(--gray-600);
}

.file-actions {
    display: flex;
    gap: var(--spacing-xs);
    opacity: 0;
    transition: var(--transition-normal);
}

.file-item:hover .file-actions {
    opacity: 1;
}

.file-action-btn {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition-fast);
    font-size: 0.9rem;
}

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

.file-action-btn.preview {
    background: var(--accent-color);
    color: white;
}

.file-action-btn:hover {
    transform: scale(1.1);
}

.batch-actions {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--gray-200);
}

/* ======================
   CONVERSION OPTIONS
   ====================== */

.conversion-options {
    background: var(--white);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--gray-200);
}

.options-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
}

.option-group {
    position: relative;
}

.option-group label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-weight: 600;
    color: var(--gray-700);
    margin-bottom: var(--spacing-md);
    font-size: 1rem;
}

.option-group label i {
    color: var(--primary-color);
    font-size: 1.1rem;
}

.modern-select {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    border: 2px solid var(--gray-300);
    border-radius: var(--radius-lg);
    font-size: 1rem;
    background: var(--white);
    color: var(--gray-800);
    transition: var(--transition-normal);
    appearance: none;
    background-image: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="%23718096" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><polyline points="6,9 12,15 18,9"></polyline></svg>');
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-size: 16px;
    padding-right: 40px;
}

.modern-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.modern-select:hover {
    border-color: var(--gray-400);
}

.advanced-options {
    background: var(--gray-50);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    border: 1px solid var(--gray-200);
    margin-top: var(--spacing-lg);
    transition: var(--transition-normal);
    max-height: 0;
    overflow: hidden;
    opacity: 0;
}

.advanced-options.show {
    max-height: 500px;
    opacity: 1;
    padding: var(--spacing-lg);
}

.options-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.option-item {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.option-item label {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--gray-700);
}

.option-item select {
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--gray-300);
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    background: var(--white);
}

.checkbox-options {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
}

.checkbox-group {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    cursor: pointer;
    user-select: none;
    position: relative;
}

.checkbox-group input[type="checkbox"] {
    appearance: none;
    width: 20px;
    height: 20px;
    border: 2px solid var(--gray-400);
    border-radius: var(--radius-sm);
    background: var(--white);
    transition: var(--transition-fast);
    cursor: pointer;
    position: relative;
}

.checkbox-group input[type="checkbox"]:checked {
    background: var(--primary-color);
    border-color: var(--primary-color);
}

.checkbox-group input[type="checkbox"]:checked::after {
    content: '✓';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: white;
    font-size: 12px;
    font-weight: bold;
}

.checkbox-group span {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--gray-700);
}

.toggle-advanced {
    text-align: center;
    margin-top: var(--spacing-lg);
}

/* ======================
   PROGRESS SECTION
   ====================== */

.progress-section {
    background: var(--white);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--gray-200);
    border-left: 4px solid var(--accent-color);
}

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

.progress-header h4 {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--gray-800);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.progress-header h4 i {
    color: var(--accent-color);
}

.progress-stats {
    font-size: 0.9rem;
    color: var(--gray-600);
    font-weight: 500;
    background: var(--gray-100);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
}

.progress-container {
    margin-bottom: var(--spacing-lg);
}

.progress-bar {
    height: 12px;
    background: var(--gray-200);
    border-radius: var(--radius-md);
    overflow: hidden;
    position: relative;
    box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.1);
}

.progress-fill {
    height: 100%;
    background: var(--gradient-secondary);
    width: 0;
    transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    border-radius: var(--radius-md);
}

.progress-fill::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    animation: shimmer 2s infinite;
}

.progress-text {
    text-align: center;
    margin-top: var(--spacing-md);
    font-weight: 500;
    color: var(--gray-700);
    font-size: 0.95rem;
}

.current-file {
    background: var(--gray-50);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.file-progress {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.file-info {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    flex: 1;
    min-width: 0;
}

.file-info i {
    color: var(--primary-color);
    font-size: 1.1rem;
}

.file-info span {
    font-weight: 500;
    color: var(--gray-800);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.mini-progress {
    width: 120px;
    height: 6px;
    background: var(--gray-300);
    border-radius: var(--radius-sm);
    overflow: hidden;
}

.mini-progress-bar {
    height: 100%;
    background: var(--success-color);
    width: 0;
    transition: width 0.3s ease;
    border-radius: var(--radius-sm);
}

.conversion-log {
    background: var(--gray-900);
    color: var(--gray-100);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    font-family: 'Courier New', monospace;
    font-size: 0.85rem;
    max-height: 200px;
    overflow-y: auto;
}

.log-entries {
    line-height: 1.4;
}

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

/* ======================
   BUTTONS & ACTIONS
   ====================== */

.btn {
    padding: var(--spacing-md) var(--spacing-xl);
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    font-weight: 600;
    font-size: 1rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    transition: var(--transition-normal);
    text-decoration: none;
    min-height: 48px;
    box-shadow: var(--shadow-sm);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-size: 0.9rem;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
}

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

.btn-primary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: var(--gradient-secondary);
    color: var(--white);
}

.btn-secondary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-success {
    background: var(--gradient-success);
    color: var(--white);
}

.btn-success:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-outline {
    background: var(--white);
    color: var(--gray-700);
    border: 2px solid var(--gray-300);
}

.btn-outline:hover:not(:disabled) {
    background: var(--gray-50);
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: translateY(-1px);
}

.btn-link {
    background: transparent;
    color: var(--primary-color);
    border: none;
    box-shadow: none;
    text-transform: none;
    letter-spacing: normal;
    font-size: 1rem;
    padding: var(--spacing-sm) var(--spacing-md);
}

.btn-link:hover {
    color: var(--primary-dark);
    text-decoration: underline;
    transform: none;
}

.action-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
    margin-top: var(--spacing-xl);
}

.download-section {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

/* Results Section */
.results-section {
    background: var(--white);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--gray-200);
    border-left: 4px solid var(--success-color);
}

.results-header {
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

.results-header h4 {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--success-color);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-md);
}

.result-item {
    background: var(--gray-50);
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    transition: var(--transition-normal);
}

.result-item:hover {
    border-color: var(--success-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* ======================
   NOTIFICATIONS & MODALS
   ====================== */

.notification {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    max-width: 400px;
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    border-left: 4px solid var(--success-color);
    animation: slideInRight 0.5s ease;
}

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

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

.notification-content {
    padding: var(--spacing-md) var(--spacing-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.notification-icon {
    font-size: 1.2rem;
    color: var(--success-color);
}

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

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

.notification-message {
    flex: 1;
    font-weight: 500;
    color: var(--gray-800);
}

.notification-close {
    background: none;
    border: none;
    color: var(--gray-500);
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: var(--radius-sm);
    transition: var(--transition-fast);
}

.notification-close:hover {
    background: var(--gray-100);
    color: var(--gray-700);
}

.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 2000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
    backdrop-filter: blur(4px);
}

.modal-content {
    background: var(--white);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    max-width: 800px;
    width: 100%;
    max-height: 90vh;
    overflow: hidden;
    animation: modalSlideIn 0.3s ease;
}

.modal-header {
    padding: var(--spacing-lg) var(--spacing-xl);
    background: var(--gradient-primary);
    color: var(--white);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h3 {
    margin: 0;
    font-size: 1.3rem;
    font-weight: 600;
}

.modal-close {
    background: none;
    border: none;
    color: var(--white);
    cursor: pointer;
    padding: var(--spacing-sm);
    border-radius: var(--radius-sm);
    transition: var(--transition-fast);
}

.modal-close:hover {
    background: rgba(255, 255, 255, 0.1);
}

.modal-body {
    padding: var(--spacing-xl);
    max-height: 60vh;
    overflow-y: auto;
}

/* ======================
   ANIMATIONS
   ====================== */

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

@keyframes modalSlideIn {
    from {
        transform: translateY(-50px) scale(0.95);
        opacity: 0;
    }
    to {
        transform: translateY(0) scale(1);
        opacity: 1;
    }
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

.pulse {
    animation: pulse 2s infinite;
}

/* ======================
   RESPONSIVE DESIGN
   ====================== */

@media (max-width: 1200px) {
    .tool-container {
        margin: var(--spacing-md);
    }
}

@media (max-width: 768px) {
    .tool-page {
        padding: var(--spacing-md) var(--spacing-sm);
    }
    
    .header-section {
        padding: var(--spacing-xl) var(--spacing-lg);
    }
    
    .header-section h1 {
        font-size: 2rem;
    }
    
    .features-grid {
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
        gap: var(--spacing-md);
    }
    
    .tool-interface {
        padding: var(--spacing-lg);
    }
    
    .upload-area {
        padding: var(--spacing-xl) var(--spacing-lg);
    }
    
    .files-grid {
        grid-template-columns: 1fr;
    }
    
    .options-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .options-row {
        grid-template-columns: 1fr;
    }
    
    .checkbox-options {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .action-buttons {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
    
    .download-section {
        flex-direction: column;
        width: 100%;
    }
    
    .results-grid {
        grid-template-columns: 1fr;
    }
    
    .notification {
        right: var(--spacing-sm);
        left: var(--spacing-sm);
        max-width: none;
    }
    
    .modal {
        padding: var(--spacing-sm);
    }
    
    .modal-content {
        width: 100%;
        max-height: 95vh;
    }
}

@media (max-width: 480px) {
    .header-section h1 {
        font-size: 1.8rem;
    }
    
    .upload-icon {
        width: 60px;
        height: 60px;
    }
    
    .upload-icon i {
        font-size: 2rem;
    }
    
    .files-section,
    .conversion-options,
    .progress-section,
    .results-section {
        padding: var(--spacing-lg);
    }
    
    .section-header {
        flex-direction: column;
        gap: var(--spacing-sm);
        text-align: center;
    }
    
    .file-stats {
        justify-content: center;
    }
}

/* Dark mode support (optional) */
@media (prefers-color-scheme: dark) {
    :root {
        --white: #1a202c;
        --gray-50: #2d3748;
        --gray-100: #4a5568;
        --gray-200: #718096;
        --gray-800: #f7fafc;
        --gray-900: #ffffff;
    }
}