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

:root {
    /* Colors */
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #a5b4fc;
    --secondary-color: #10b981;
    --accent-color: #f59e0b;
    --danger-color: #ef4444;
    
    /* Neutrals */
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;
}

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--gray-800);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Header */
.header {
    padding: var(--spacing-2xl) 0;
    text-align: center;
    color: white;
}

.header-content {
    max-width: 600px;
    margin: 0 auto;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.logo i {
    font-size: var(--font-size-4xl);
    color: var(--primary-light);
}

.logo h1 {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    margin: 0;
}

.subtitle {
    font-size: var(--font-size-xl);
    opacity: 0.9;
    font-weight: 300;
}

/* Main Content */
.main-content {
    background: white;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    margin-bottom: var(--spacing-3xl);
    overflow: hidden;
}

.generator-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
    padding: var(--spacing-2xl);
}

/* Section Headers */
.section-header {
    margin-bottom: var(--spacing-xl);
}

.section-header h2 {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: var(--font-size-2xl);
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: var(--spacing-xs);
}

.section-header h2 i {
    color: var(--primary-color);
}

.section-header p {
    color: var(--gray-600);
    font-size: var(--font-size-sm);
}

/* Content Tabs */
.content-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-xl);
    padding: var(--spacing-xs);
    background: var(--gray-100);
    border-radius: var(--radius-lg);
}

.tab-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    border: none;
    background: transparent;
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--gray-600);
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

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

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

/* Content Forms */
.content-forms {
    position: relative;
}

.content-form {
    display: none;
}

.content-form.active {
    display: block;
}

.input-group {
    margin-bottom: var(--spacing-lg);
}

.input-group label {
    display: block;
    font-weight: 500;
    color: var(--gray-700);
    margin-bottom: var(--spacing-sm);
    font-size: var(--font-size-sm);
}

.form-input,
.form-textarea,
.form-select {
    width: 100%;
    padding: var(--spacing-md);
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-md);
    font-size: var(--font-size-base);
    transition: all var(--transition-fast);
    background: white;
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgb(99 102 241 / 0.1);
}

.form-textarea {
    resize: vertical;
    min-height: 100px;
}

.checkbox-group {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

.checkbox-group input[type="checkbox"] {
    width: auto;
    margin: 0;
}

/* Customization Section */
.customization-grid {
    display: grid;
    gap: var(--spacing-xl);
}

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

.custom-group label {
    font-weight: 500;
    color: var(--gray-700);
    font-size: var(--font-size-sm);
}

/* Size Control */
.size-control {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.range-slider {
    flex: 1;
    height: 6px;
    border-radius: 3px;
    background: var(--gray-200);
    outline: none;
    -webkit-appearance: none;
}

.range-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    box-shadow: var(--shadow-sm);
}

.range-slider::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    border: none;
    box-shadow: var(--shadow-sm);
}

.size-value {
    font-weight: 600;
    color: var(--primary-color);
    min-width: 60px;
    text-align: right;
}

/* Color Controls */
.color-controls {
    display: flex;
    gap: var(--spacing-lg);
}

.color-input-group {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.color-input-group label {
    font-size: var(--font-size-xs);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--gray-500);
}

.color-picker {
    width: 100%;
    height: 50px;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.color-picker:hover {
    border-color: var(--primary-color);
}

/* Preview Section */
.preview-section {
    display: flex;
    flex-direction: column;
    height: 100%;
}

.preview-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.qr-preview {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gray-50);
    border: 2px dashed var(--gray-300);
    border-radius: var(--radius-lg);
    min-height: 300px;
    transition: all var(--transition-normal);
}

.qr-preview.has-qr {
    border-style: solid;
    border-color: var(--primary-color);
    background: white;
}

.qr-preview .placeholder {
    text-align: center;
    color: var(--gray-500);
}

.qr-preview .placeholder i {
    font-size: var(--font-size-4xl);
    margin-bottom: var(--spacing-md);
    opacity: 0.5;
}

.qr-preview img {
    max-width: 100%;
    max-height: 100%;
    border-radius: var(--radius-md);
}

/* Preview Actions */
.preview-actions {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    border: none;
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

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

.btn-secondary:hover:not(:disabled) {
    background: #059669;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

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

.btn-outline:hover:not(:disabled) {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

/* Features Section */
.features-section {
    background: white;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    margin-bottom: var(--spacing-3xl);
    padding: var(--spacing-3xl) var(--spacing-2xl);
}

.features-container h2 {
    text-align: center;
    font-size: var(--font-size-3xl);
    font-weight: 700;
    color: var(--gray-800);
    margin-bottom: var(--spacing-2xl);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
}

.feature-card {
    text-align: center;
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    background: var(--gray-50);
    transition: all var(--transition-normal);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    width: 60px;
    height: 60px;
    margin: 0 auto var(--spacing-lg);
    background: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: var(--font-size-xl);
}

.feature-card h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: var(--spacing-sm);
}

.feature-card p {
    color: var(--gray-600);
    line-height: 1.6;
}

/* Footer */
.footer {
    text-align: center;
    padding: var(--spacing-2xl) 0;
    color: white;
}

.footer-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    align-items: center;
}

.footer-links {
    display: flex;
    gap: var(--spacing-lg);
}

.footer-link {
    color: white;
    text-decoration: none;
    opacity: 0.8;
    transition: opacity var(--transition-fast);
}

.footer-link:hover {
    opacity: 1;
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

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

.loading-spinner {
    background: white;
    padding: var(--spacing-2xl);
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-xl);
}

.loading-spinner i {
    font-size: var(--font-size-3xl);
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    top: var(--spacing-xl);
    right: var(--spacing-xl);
    z-index: 1001;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.toast {
    background: white;
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    border-left: 4px solid var(--primary-color);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    min-width: 300px;
    animation: slideIn 0.3s ease-out;
}

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

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

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

.toast.success i {
    color: var(--secondary-color);
}

.toast.error i {
    color: var(--danger-color);
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .generator-container {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
        padding: var(--spacing-xl);
    }
    
    .content-tabs {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .tab-btn {
        justify-content: center;
        padding: var(--spacing-sm);
    }
    
    .tab-btn span {
        display: none;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .preview-actions {
        flex-direction: column;
    }
    
    .btn {
        justify-content: center;
    }
    
    .color-controls {
        flex-direction: column;
    }
    
    .footer-content {
        gap: var(--spacing-sm);
    }
    
    .footer-links {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
    
    .toast-container {
        left: var(--spacing-sm);
        right: var(--spacing-sm);
    }
    
    .toast {
        min-width: auto;
    }
}

@media (max-width: 480px) {
    .logo {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
    
    .logo h1 {
        font-size: var(--font-size-3xl);
    }
    
    .subtitle {
        font-size: var(--font-size-lg);
    }
    
    .content-tabs {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Print Styles */
@media print {
    .header,
    .features-section,
    .footer,
    .preview-actions {
        display: none;
    }
    
    .main-content {
        box-shadow: none;
        border: 1px solid var(--gray-300);
    }
    
    .generator-container {
        grid-template-columns: 1fr;
    }
    
    .qr-preview {
        border: 1px solid var(--gray-300);
        background: white;
    }
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
    :root {
        --gray-100: #e0e0e0;
        --gray-200: #c0c0c0;
        --gray-300: #a0a0a0;
    }
    
    .btn-outline {
        border-width: 3px;
    }
    
    .form-input:focus,
    .form-textarea:focus,
    .form-select:focus {
        border-width: 3px;
    }
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    .loading-spinner i {
        animation: none;
    }
}