/* CSS Reset & Variables */
:root {
    --bg-primary: #0f0f1a;
    --bg-secondary: #1a1a2e;
    --bg-tertiary: #252545;
    --bg-card: rgba(30, 30, 60, 0.6);
    --text-primary: #ffffff;
    --text-secondary: #a0a0c0;
    --text-muted: #6b6b8a;
    --accent-primary: #6366f1;
    --accent-secondary: #8b5cf6;
    --accent-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a855f7 100%);
    --success: #22c55e;
    --border-color: rgba(255, 255, 255, 0.1);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.4);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
    background-image: 
        radial-gradient(ellipse at 20% 20%, rgba(99, 102, 241, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(139, 92, 246, 0.1) 0%, transparent 50%);
}

/* App Container */
.app-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.header {
    text-align: center;
    padding: 40px 20px 30px;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-bottom: 8px;
}

.logo-icon {
    width: 48px;
    height: 48px;
    background: var(--accent-gradient);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 10px;
}

.logo-icon svg {
    width: 100%;
    height: 100%;
    color: white;
}

.logo h1 {
    font-size: 2rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

/* Main Content */
.main-content {
    flex: 1;
}

/* QR Type Tabs */
.qr-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
    padding: 20px;
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    margin-bottom: 30px;
    backdrop-filter: blur(20px);
}

.tab-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    background: transparent;
    border: 2px solid transparent;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    font-family: inherit;
}

.tab-btn svg {
    width: 18px;
    height: 18px;
    stroke-width: 2;
}

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

.tab-btn.active {
    background: rgba(99, 102, 241, 0.15);
    border-color: var(--accent-primary);
    color: var(--text-primary);
}

/* Content Wrapper */
.content-wrapper {
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: 30px;
    align-items: start;
}

/* Form Section */
.form-section {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    padding: 30px;
    backdrop-filter: blur(20px);
}

.form-content {
    display: none;
}

.form-content.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

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

.form-content h2 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 8px;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.form-description {
    color: var(--text-secondary);
    margin-bottom: 24px;
    font-size: 0.95rem;
}

.form-group {
    margin-bottom: 20px;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.form-group label {
    display: block;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 14px 16px;
    background: var(--bg-tertiary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1rem;
    font-family: inherit;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.15);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--text-muted);
}

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

.form-group select {
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='%23a0a0c0' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-size: 20px;
}

.input-hint {
    display: block;
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 6px;
}

/* Checkbox Group */
.checkbox-group {
    display: flex;
    align-items: center;
    gap: 10px;
}

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

.checkbox-group label {
    margin-bottom: 0;
    cursor: pointer;
}

/* Customization Section */
.customization-section {
    margin-top: 30px;
    padding-top: 24px;
    border-top: 1px solid var(--border-color);
}

.customization-section h3 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 16px;
}

.custom-options {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
}

.color-group {
    flex: 1;
    min-width: 120px;
}

.color-input-wrapper {
    display: flex;
    align-items: center;
    gap: 10px;
    background: var(--bg-tertiary);
    padding: 8px 12px;
    border-radius: var(--radius-md);
    border: 2px solid var(--border-color);
}

.color-input-wrapper input[type="color"] {
    width: 32px;
    height: 32px;
    padding: 0;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    background: transparent;
}

.color-input-wrapper input[type="color"]::-webkit-color-swatch-wrapper {
    padding: 0;
}

.color-input-wrapper input[type="color"]::-webkit-color-swatch {
    border: none;
    border-radius: 6px;
}

.color-value {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-family: 'SF Mono', Monaco, monospace;
}

.size-group {
    flex: 1;
    min-width: 140px;
}

/* Generate Button */
.generate-btn {
    width: 100%;
    padding: 16px 24px;
    margin-top: 24px;
    background: var(--accent-gradient);
    border: none;
    border-radius: var(--radius-md);
    color: white;
    font-size: 1.1rem;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    transition: var(--transition);
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.4);
}

.generate-btn svg {
    width: 24px;
    height: 24px;
}

.generate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 30px rgba(99, 102, 241, 0.5);
}

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

/* Preview Section */
.preview-section {
    position: sticky;
    top: 20px;
}

.preview-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    padding: 30px;
    backdrop-filter: blur(20px);
    text-align: center;
}

.preview-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.qr-preview {
    min-height: 250px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: white;
    border-radius: var(--radius-md);
    padding: 20px;
    margin-bottom: 20px;
}

.qr-preview .placeholder {
    text-align: center;
    color: #999;
}

.qr-preview .placeholder svg {
    width: 80px;
    height: 80px;
    margin-bottom: 16px;
    opacity: 0.3;
}

.qr-preview .placeholder p {
    font-size: 0.95rem;
}

.qr-preview canvas,
.qr-preview svg,
.qr-preview img {
    max-width: 100%;
    height: auto;
}

/* Download Options */
.download-options {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.download-btn {
    flex: 1;
    min-width: 140px;
    padding: 12px 20px;
    background: var(--bg-tertiary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.95rem;
    font-weight: 500;
    font-family: inherit;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: var(--transition);
}

.download-btn svg {
    width: 18px;
    height: 18px;
}

.download-btn:hover {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
}

/* Footer */
.footer {
    text-align: center;
    padding: 30px 20px;
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .content-wrapper {
        grid-template-columns: 1fr;
    }
    
    .preview-section {
        position: static;
        order: -1;
    }
    
    .preview-card {
        margin-bottom: 30px;
    }
}

@media (max-width: 768px) {
    .app-container {
        padding: 15px;
    }
    
    .header {
        padding: 30px 15px 20px;
    }
    
    .logo h1 {
        font-size: 1.6rem;
    }
    
    .qr-tabs {
        padding: 15px;
        gap: 6px;
    }
    
    .tab-btn {
        padding: 8px 12px;
        font-size: 0.8rem;
    }
    
    .tab-btn span {
        display: none;
    }
    
    .tab-btn.active span {
        display: inline;
    }
    
    .form-section {
        padding: 20px;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .custom-options {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .logo-icon {
        width: 40px;
        height: 40px;
    }
    
    .logo h1 {
        font-size: 1.4rem;
    }
    
    .tab-btn {
        padding: 8px 10px;
    }
    
    .form-content h2 {
        font-size: 1.3rem;
    }
}

/* Barcode specific styles */
#qr-preview svg[id^="barcode"] {
    max-width: 100%;
    height: auto;
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--success);
    color: white;
    padding: 14px 24px;
    border-radius: var(--radius-md);
    font-weight: 500;
    box-shadow: var(--shadow-md);
    z-index: 1000;
    opacity: 0;
    transition: var(--transition);
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}