/* Excel ⇄ PDF Converter - Modern Blue Theme */

:root {
    /* Light Theme - Blue Shades */
    --primary-50: #eff6ff;
    --primary-100: #dbeafe;
    --primary-200: #bfdbfe;
    --primary-300: #93c5fd;
    --primary-400: #60a5fa;
    --primary-500: #3b82f6;
    --primary-600: #2563eb;
    --primary-700: #1d4ed8;
    --primary-800: #1e40af;
    --primary-900: #1e3a8a;
    --primary-950: #172554;
    
    /* UI Variables - Light */
    --bg-color: #f8fafc;
    --card-bg: rgba(255, 255, 255, 0.95);
    --text-color: #1e293b;
    --text-light: #64748b;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 40px -10px rgba(0, 0, 0, 0.15);
    --glass-bg: rgba(255, 255, 255, 0.85);
    --glass-border: rgba(255, 255, 255, 0.2);
    --gradient-primary: linear-gradient(135deg, var(--primary-500), var(--primary-700));
    --gradient-accent: linear-gradient(135deg, var(--primary-400), var(--primary-600));
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    /* Transitions - FIXED: Reduced animations */
    --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark Theme Variables - More Blue */
[data-theme="dark"] {
    --bg-color: #0f172a;
    --card-bg: rgba(30, 41, 59, 0.95);
    --text-color: #f1f5f9;
    --text-light: #94a3b8;
    --border-color: #334155;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.4);
    --shadow-xl: 0 20px 40px -10px rgba(0, 0, 0, 0.5);
    --glass-bg: rgba(30, 41, 59, 0.85);
    --glass-border: rgba(255, 255, 255, 0.1);
    --primary-800: #1e3a8a;
    --primary-900: #1e3a8a;
}

/* Reset & Base Styles - FIXED: Reduced animations */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    animation-duration: 0.2s !important;
    transition-duration: 0.2s !important;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    transition: var(--transition);
    min-height: 100vh;
    overflow-x: hidden;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Header & Navigation */
.header {
    background: var(--gradient-primary);
    backdrop-filter: blur(10px);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-lg);
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 1rem;
    color: white;
}

.logo i {
    font-size: 2.5rem;
    background: rgba(255, 255, 255, 0.1);
    padding: 0.75rem;
    border-radius: var(--radius-md);
    backdrop-filter: blur(10px);
}

.logo h1 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.tagline {
    font-size: 0.9rem;
    opacity: 0.9;
    font-weight: 400;
}

.nav-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

/* Theme Switch */
.theme-switch {
    position: relative;
}

.theme-label {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    background: rgba(255, 255, 255, 0.1);
    padding: 0.5rem 1rem;
    border-radius: 50px;
    cursor: pointer;
    position: relative;
    width: 80px;
    height: 40px;
    backdrop-filter: blur(10px);
}

.theme-label i {
    font-size: 1.25rem;
    color: white;
    z-index: 2;
    transition: var(--transition);
}

.theme-label .fa-sun {
    opacity: 0.8;
}

.theme-label .fa-moon {
    opacity: 0.8;
}

.theme-ball {
    position: absolute;
    left: 0.5rem;
    width: 32px;
    height: 32px;
    background: white;
    border-radius: 50%;
    transition: transform 0.3s ease;
    z-index: 1;
}

#themeToggle:checked + .theme-label .theme-ball {
    transform: translateX(40px);
}

#themeToggle:checked + .theme-label .fa-sun {
    opacity: 0.5;
}

#themeToggle:checked + .theme-label .fa-moon {
    opacity: 1;
}

.help-btn {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    border: none;
    color: white;
    font-size: 1.25rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    backdrop-filter: blur(10px);
}

.help-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

/* Main Content */
main {
    padding: 2rem 0;
}

/* Section Headers */
.section-header {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.section-icon {
    width: 70px;
    height: 70px;
    background: var(--gradient-primary);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: white;
}

.section-header h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, var(--primary-600), var(--primary-800));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.section-subtitle {
    color: var(--text-light);
    font-size: 1rem;
}

/* Glass Card */
.glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border-radius: var(--radius-xl);
    border: 1px solid var(--glass-border);
    box-shadow: var(--shadow-xl);
    transition: var(--transition);
}

.glass-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl), 0 30px 60px rgba(0, 0, 0, 0.1);
}

/* Converter Card */
.converter-card {
    display: grid;
    grid-template-columns: 1fr 1.2fr 1fr;
    gap: 2rem;
    padding: 2.5rem;
    margin-bottom: 3rem;
}

@media (max-width: 1200px) {
    .converter-card {
        grid-template-columns: 1fr;
    }
}

/* Upload Panel */
.upload-panel {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.upload-area {
    border: 3px dashed var(--primary-400);
    border-radius: var(--radius-lg);
    padding: 2.5rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    background: rgba(59, 130, 246, 0.05);
    position: relative;
}

.upload-area:hover {
    border-color: var(--primary-500);
    background: rgba(59, 130, 246, 0.1);
}

.upload-area.dragover {
    border-color: var(--primary-500);
    background: rgba(59, 130, 246, 0.15);
    animation: pulseBorder 1.5s infinite;
}

@keyframes pulseBorder {
    0%, 100% { 
        border-width: 3px;
        border-style: dashed;
    }
    50% { 
        border-width: 4px;
        border-style: solid;
    }
}

.upload-icon {
    font-size: 3.5rem;
    color: var(--primary-500);
    margin-bottom: 1.5rem;
    background: rgba(59, 130, 246, 0.1);
    width: 100px;
    height: 100px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
}

.upload-area h3 {
    font-size: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-color);
}

.upload-area p {
    color: var(--text-light);
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
}

.file-info {
    font-size: 0.85rem;
    color: var(--primary-500) !important;
    font-weight: 500;
    margin-top: 0.5rem;
}

.file-info:after {
    content: " • Ctrl+V for Google Drive";
    color: var(--primary-600);
    font-weight: 600;
}

/* Buttons */
.btn {
    padding: 0.875rem 1.75rem;
    border: none;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
}

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

.btn-gradient:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(59, 130, 246, 0.3);
}

.btn-outline {
    background: transparent;
    color: var(--primary-600);
    border: 2px solid var(--primary-600);
}

.btn-outline:hover {
    background: var(--primary-600);
    color: white;
    transform: translateY(-2px);
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
}

/* Cancel Button */
.cancel-btn {
    background: linear-gradient(135deg, #ef4444, #dc2626);
    color: white;
    border: none;
}

.cancel-btn:hover {
    background: linear-gradient(135deg, #dc2626, #b91c1c);
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(239, 68, 68, 0.3);
}

/* Selected File */
.selected-file {
    margin-top: 1.5rem;
    padding: 1.25rem;
    background: var(--card-bg);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--primary-500);
    display: none;
    animation: fadeIn 0.3s ease;
}

.selected-file.show {
    display: block;
}

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

/* Sheet Selector */
.sheet-selector, .page-selector {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    border: 1px solid var(--border-color);
}

.sheet-selector h4, .page-selector h4 {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

/* Sheet Controls */
.sheet-controls {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.sheet-controls button {
    flex: 1;
    padding: 0.5rem 0.75rem;
    font-size: 0.85rem;
    background: var(--primary-100);
    border: 1px solid var(--primary-300);
    color: var(--primary-700);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
}

.sheet-controls button:hover {
    background: var(--primary-200);
}

.sheets-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    max-height: 200px;
    overflow-y: auto;
}

.sheet-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    background: var(--bg-color);
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    cursor: pointer;
    transition: var(--transition);
}

.sheet-item:hover {
    background: var(--primary-50);
    border-color: var(--primary-300);
}

.sheet-item.selected {
    background: var(--primary-100);
    border-color: var(--primary-500);
    color: var(--primary-700);
}

/* File Delete Button */
.delete-file {
    background: transparent;
    border: none;
    color: var(--text-light);
    cursor: pointer;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    transition: var(--transition);
}

.delete-file:hover {
    color: #ef4444;
    background: rgba(239, 68, 68, 0.1);
}

/* Settings Panel */
.settings-panel {
    display: flex;
    flex-direction: column;
}

.settings-panel h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-color);
}

.settings-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
    flex-grow: 1;
}

@media (max-width: 768px) {
    .settings-grid {
        grid-template-columns: 1fr;
    }
}

.setting-group {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.setting-group.full-width {
    grid-column: 1 / -1;
}

.setting-group label {
    font-weight: 600;
    color: var(--text-color);
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.tooltip {
    font-size: 0.8rem;
    color: var(--primary-500);
    cursor: help;
    margin-left: auto;
}

.setting-input {
    padding: 0.875rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--bg-color);
    color: var(--text-color);
    font-size: 0.95rem;
    transition: var(--transition);
    width: 100%;
}

.setting-input:focus {
    outline: none;
    border-color: var(--primary-500);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

/* Button Groups */
.btn-group {
    display: flex;
    gap: 0.5rem;
}

.option-btn {
    flex: 1;
    padding: 0.875rem;
    border: 2px solid var(--border-color);
    background: var(--bg-color);
    color: var(--text-color);
    border-radius: var(--radius-sm);
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
    font-size: 0.9rem;
}

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

.option-btn.active {
    background: var(--primary-500);
    color: white;
    border-color: var(--primary-500);
}

/* Slider */
.slider {
    width: 100%;
    height: 8px;
    border-radius: 4px;
    background: var(--border-color);
    outline: none;
    -webkit-appearance: none;
}

.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--primary-500);
    cursor: pointer;
    border: 3px solid var(--card-bg);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

.slider::-webkit-slider-thumb:hover {
    background: var(--primary-600);
}

/* Checkbox */
.checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    cursor: pointer;
    padding: 0.5rem 0;
}

.checkbox-label input[type="checkbox"] {
    width: 20px;
    height: 20px;
    accent-color: var(--primary-500);
}

/* Color Picker */
.color-picker {
    width: 100%;
    height: 40px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    cursor: pointer;
    padding: 0.25rem;
    background: var(--bg-color);
}

/* Range Inputs */
.range-inputs {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

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

.input-group label {
    font-size: 0.9rem;
    color: var(--text-light);
}

/* Action Buttons */
.action-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

/* Preview Panel */
.preview-panel {
    display: flex;
    flex-direction: column;
}

.preview-panel h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-color);
}

.preview-container {
    flex-grow: 1;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    background: var(--bg-color);
    padding: 1.5rem;
    min-height: 300px;
    overflow: auto;
    margin-bottom: 1.5rem;
}

.preview-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    color: var(--text-light);
    text-align: center;
}

.preview-placeholder i {
    font-size: 3.5rem;
    margin-bottom: 1.5rem;
    opacity: 0.5;
}

/* Preview Controls */
.preview-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-top: 1rem;
}

.preview-info {
    margin-left: auto;
    font-size: 0.9rem;
    color: var(--text-light);
}

/* Progress Container - FIXED: Smooth transitions */
.progress-container {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    margin-top: 1.5rem;
}

.progress-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    font-weight: 600;
    color: var(--text-color);
}

.progress-bar {
    height: 10px;
    background: var(--border-color);
    border-radius: 5px;
    overflow: hidden;
    margin-bottom: 0.75rem;
}

.progress-fill {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, 
        var(--primary-400), 
        var(--primary-500), 
        var(--primary-600)
    );
    border-radius: 5px;
    transition: width 0.5s ease !important; /* FIXED: Smooth transition */
}

.progress-details {
    font-size: 0.9rem;
    color: var(--text-light);
    text-align: center;
    min-height: 20px;
}

/* Preview Stats */
.preview-stats {
    margin-top: 1rem;
    padding: 1rem;
    background: var(--card-bg);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    font-size: 0.9rem;
    color: var(--text-light);
}

/* Features Section */
.features-section {
    margin: 4rem 0 3rem;
}

.features-section h2 {
    font-size: 2.25rem;
    text-align: center;
    margin-bottom: 3rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
}

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

.feature-card {
    padding: 2.5rem;
    text-align: center;
    border-radius: var(--radius-xl);
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-10px);
}

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: white;
}

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

.feature-card p {
    color: var(--text-light);
    font-size: 1rem;
    line-height: 1.7;
}

/* Footer */
.footer {
    background: var(--card-bg);
    padding: 4rem 0 2rem;
    margin-top: 4rem;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-logo {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.footer-logo i {
    font-size: 3rem;
    color: var(--primary-500);
}

.footer-logo h3 {
    font-size: 1.75rem;
    font-weight: 700;
}

.footer-logo p {
    color: var(--text-light);
}

.tech-stack h4, .footer-tips h4 {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-color);
}

.tech-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.tech-tag {
    background: var(--bg-color);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.85rem;
    color: var(--text-color);
    border: 1px solid var(--border-color);
}

.footer-tips ul {
    list-style: none;
    padding-left: 0;
}

.footer-tips li {
    margin-bottom: 0.75rem;
    color: var(--text-light);
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
}

.footer-tips li:before {
    content: "✓";
    color: var(--primary-500);
    font-weight: bold;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-light);
}

.disclaimer {
    font-size: 0.9rem;
    margin-top: 0.5rem;
    opacity: 0.8;
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    backdrop-filter: blur(5px);
}

.modal-content {
    max-width: 800px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    padding: 2.5rem;
    border-radius: var(--radius-xl);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h2 {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.75rem;
}

.modal-close {
    background: none;
    border: none;
    font-size: 2.5rem;
    color: var(--text-light);
    cursor: pointer;
    line-height: 1;
    padding: 0;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.modal-close:hover {
    color: var(--primary-500);
    transform: rotate(90deg);
}

/* Instructions */
.instructions {
    margin-bottom: 2rem;
}

.instruction-step {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
    align-items: flex-start;
}

.step-number {
    background: var(--gradient-primary);
    color: white;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    flex-shrink: 0;
    font-size: 1.1rem;
}

.step-content h4 {
    margin-bottom: 0.5rem;
    color: var(--text-color);
    font-size: 1.25rem;
}

.tips-section {
    background: var(--bg-color);
    padding: 2rem;
    border-radius: var(--radius-lg);
    margin-top: 2rem;
}

.tips-section h3 {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
}

.tips-section ul {
    padding-left: 1.5rem;
}

.tips-section li {
    margin-bottom: 0.75rem;
    color: var(--text-light);
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 3000;
    backdrop-filter: blur(10px);
}

.loading-content {
    padding: 3rem;
    border-radius: var(--radius-xl);
    text-align: center;
    max-width: 500px;
    width: 90%;
}

.loading-spinner {
    width: 80px;
    height: 80px;
    border: 5px solid var(--border-color);
    border-top-color: var(--primary-500);
    border-radius: 50%;
    margin: 0 auto 2rem;
    animation: spin 1s linear infinite;
}

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

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

.stat {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
}

.stat i {
    color: var(--primary-500);
    font-size: 1.5rem;
}

/* Notification */
.notification {
    position: fixed;
    top: 20px;
    right: 20px;
    padding: 1.25rem 1.75rem;
    border-radius: var(--radius-lg);
    background: var(--primary-500);
    color: white;
    display: flex;
    align-items: center;
    gap: 1rem;
    box-shadow: var(--shadow-xl);
    z-index: 4000;
    animation: slideIn 0.3s ease;
    max-width: 400px;
}

.notification.success {
    background: var(--primary-500);
}

.notification.error {
    background: #ef4444;
}

.notification.warning {
    background: #f59e0b;
}

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

/* Responsive Design */
@media (max-width: 1024px) {
    .converter-card {
        grid-template-columns: 1fr;
        padding: 2rem;
    }
    
    .section-header {
        flex-direction: column;
        text-align: center;
        gap: 1rem;
    }
    
    .settings-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 1.5rem;
    }
    
    .navbar {
        flex-direction: column;
        gap: 1.5rem;
        text-align: center;
    }
    
    .action-buttons {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .tech-tags {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .converter-card {
        padding: 1.5rem;
    }
    
    .upload-area {
        padding: 2rem 1.5rem;
    }
    
    .section-header h2 {
        font-size: 1.75rem;
    }
    
    .features-section h2 {
        font-size: 2rem;
    }
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-color);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb {
    background: var(--primary-300);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-400);
}

/* Table Preview Styling */
.table-preview {
    width: 100%;
    border-collapse: collapse;
    font-size: 14px;
}

.table-preview th {
    background: var(--primary-100);
    padding: 12px;
    text-align: left;
    border: 1px solid var(--border-color);
    font-weight: 600;
}

.table-preview td {
    padding: 10px 12px;
    border: 1px solid var(--border-color);
}

.table-preview tr:nth-child(even) {
    background: rgba(0, 0, 0, 0.02);
}

[data-theme="dark"] .table-preview tr:nth-child(even) {
    background: rgba(255, 255, 255, 0.05);
}

/* Touch improvements */
@media (hover: none) and (pointer: coarse) {
    .btn, .option-btn, .sheet-item {
        min-height: 44px;
        min-width: 44px;
    }
    
    .upload-area {
        min-height: 200px;
        display: flex;
        flex-direction: column;
        justify-content: center;
    }
}
/* Prevent flash on file upload */
input[type="file"] {
    display: none;
}

.upload-area {
    transition: all 0.2s ease !important;
}