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

:root {
    --primary-color: #6366f1;
    --primary-hover: #5855eb;
    --secondary-color: #f8fafc;
    --accent-color: #10b981;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --error-color: #ef4444;
    --success-color: #10b981;
    --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: 12px;
    --border-radius-sm: 8px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    animation: fadeInUp 0.6s ease-out;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    color: white;
    padding: 40px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.header::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>');
    opacity: 0.3;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    margin-bottom: 15px;
    position: relative;
    z-index: 1;
}

.logo i {
    font-size: 2.5rem;
    animation: pulse 2s infinite;
}

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

.logo h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin: 0;
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
    font-weight: 300;
    position: relative;
    z-index: 1;
}

/* Основной контент */
.main-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    padding: 40px;
}

.form-section {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.input-group label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 500;
    color: var(--text-primary);
    font-size: 0.95rem;
}

.input-group label i {
    color: var(--primary-color);
    width: 16px;
}

.url-input {
    width: 100%;
    padding: 15px 20px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    font-size: 1rem;
    transition: var(--transition);
    background: white;
}

.url-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
    transform: translateY(-1px);
}

.file-input-wrapper {
    position: relative;
}

.file-input {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
}

.file-input-label {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 15px 20px;
    border: 2px dashed var(--border-color);
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    transition: var(--transition);
    background: var(--secondary-color);
    font-weight: 500;
}

.file-input-label:hover {
    border-color: var(--primary-color);
    background: rgba(99, 102, 241, 0.05);
    transform: translateY(-1px);
}

.logo-preview {
    position: relative;
    display: inline-block;
    margin-top: 10px;
    border-radius: var(--border-radius-sm);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    animation: fadeIn 0.3s ease-out;
}

.logo-preview.hidden {
    display: none;
}

.logo-preview img {
    width: 80px;
    height: 80px;
    object-fit: cover;
    display: block;
}

.remove-logo {
    position: absolute;
    top: -8px;
    right: -8px;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--error-color);
    color: white;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    transition: var(--transition);
}

.remove-logo:hover {
    background: #dc2626;
    transform: scale(1.1);
}

.color-input-wrapper {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 10px 15px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    background: white;
    transition: var(--transition);
}

.color-input-wrapper:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-sm);
}

.color-input {
    width: 50px;
    height: 50px;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    transition: var(--transition);
}

.color-input:hover {
    transform: scale(1.05);
}

.color-value,
.bg-color-value {
    font-family: 'Courier New', monospace;
    font-weight: 500;
    color: var(--text-secondary);
    background: var(--secondary-color);
    padding: 5px 10px;
    border-radius: 4px;
    font-size: 0.9rem;
}

.generate-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 18px 30px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    color: white;
    border: none;
    border-radius: var(--border-radius-sm);
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-md);
    margin-top: 10px;
}

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

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

.generate-btn:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}

.preview-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 25px;
}

.qr-preview-container {
    width: 100%;
    max-width: 350px;
    aspect-ratio: 1;
    border: 2px dashed var(--border-color);
    border-radius: var(--border-radius);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--secondary-color);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.qr-preview {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.placeholder {
    text-align: center;
    color: var(--text-secondary);
}

.placeholder i {
    font-size: 3rem;
    margin-bottom: 15px;
    opacity: 0.5;
}

.placeholder p {
    font-size: 1.1rem;
    font-weight: 500;
}

.qr-canvas {
    max-width: 100%;
    max-height: 100%;
    border-radius: var(--border-radius-sm);
    box-shadow: var(--shadow-md);
    animation: zoomIn 0.5s ease-out;
}

@keyframes zoomIn {
    from {
        opacity: 0;
        transform: scale(0.8);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.download-section {
    width: 100%;
    animation: slideUp 0.4s ease-out;
}

.download-section.hidden {
    display: none;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.download-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    width: 100%;
    padding: 15px 25px;
    background: linear-gradient(135deg, var(--accent-color) 0%, #059669 100%);
    color: white;
    border: none;
    border-radius: var(--border-radius-sm);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-md);
}

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

.footer {
    background: var(--secondary-color);
    padding: 25px 40px;
    text-align: center;
    color: var(--text-secondary);
    border-top: 1px solid var(--border-color);
}

.error-message {
    position: fixed;
    top: 20px;
    right: 20px;
    background: var(--error-color);
    color: white;
    padding: 15px 20px;
    border-radius: var(--border-radius-sm);
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 10px;
    z-index: 1000;
    animation: slideInRight 0.3s ease-out;
}

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

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@media (max-width: 768px) {
    body {
        padding: 10px;
    }
    
    .main-content {
        grid-template-columns: 1fr;
        gap: 30px;
        padding: 30px 20px;
    }
    
    .header {
        padding: 30px 20px;
    }
    
    .logo h1 {
        font-size: 2rem;
    }
    
    .logo i {
        font-size: 2rem;
    }
    
    .subtitle {
        font-size: 1rem;
    }
    
    .qr-preview-container {
        max-width: 280px;
    }
}

@media (max-width: 480px) {
    .header {
        padding: 25px 15px;
    }
    
    .main-content {
        padding: 25px 15px;
    }
    
    .logo {
        flex-direction: column;
        gap: 10px;
    }
    
    .logo h1 {
        font-size: 1.8rem;
    }
    
    .color-input-wrapper {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }
    
    .qr-preview-container {
        max-width: 250px;
    }
}

@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

@media (prefers-color-scheme: dark) {
    :root {
        --text-primary: #f9fafb;
        --text-secondary: #d1d5db;
        --border-color: #374151;
        --secondary-color: #1f2937;
    }
    
    .container {
        background: #111827;
        color: var(--text-primary);
    }
    
    .url-input,
    .color-input-wrapper {
        background: #1f2937;
        border-color: var(--border-color);
        color: var(--text-primary);
    }
    
    .file-input-label {
        background: #1f2937;
        color: var(--text-primary);
    }
    
    .qr-preview-container {
        background: #1f2937;
        border-color: var(--border-color);
    }
}