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

:root {
    --primary: #06B6D4;          
    --primary-dark: #0891B2;     
    --success: #10B981;          
    --warning: #F59E0B;          
    --bg: #0A1929;               
    --surface: #1A2332;          
    --surface-hover: #243447;    
    --text: #E1F5FE;             
    --text-secondary: #90CAF9;   
    --border: #2C3E50;           
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

.header {
    text-align: center;
    margin-bottom: 3rem;
}

.header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.upload-section {
    margin-bottom: 3rem;
}

.upload-area {
    border: 2px dashed var(--border);
    border-radius: 1rem;
    padding: 3rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: var(--surface);
}

.upload-area:hover {
    border-color: var(--primary);
    background: var(--surface-hover);
}

.upload-area.dragover {
    border-color: var(--primary);
    background: var(--surface-hover);
    transform: scale(1.02);
}

.upload-content svg {
    color: var(--primary);
    margin-bottom: 1rem;
}

.upload-content h3 {
    margin-bottom: 0.5rem;
}

.upload-content p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.supported-formats {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: var(--surface-hover);
    border-radius: 0.5rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.preview-section {
    margin-bottom: 3rem;
}

.preview-section h2 {
    margin-bottom: 1.5rem;
}

.original-preview {
    background: var(--surface);
    border-radius: 1rem;
    padding: 2rem;
    text-align: center;
    margin-bottom: 2rem;
}

.original-preview img {
    max-width: 200px;
    max-height: 200px;
    border-radius: 0.5rem;
    margin-bottom: 1rem;
}

.image-info {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.size-selector {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.preset-btn {
    padding: 0.75rem 1.5rem;
    background: var(--surface);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    cursor: pointer;
    font-size: 0.875rem;
    transition: all 0.2s;
}

.preset-btn:hover {
    background: var(--surface-hover);
    border-color: var(--primary);
}

.sizes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.size-item {
    background: var(--surface);
    border: 2px solid var(--border);
    border-radius: 0.75rem;
    padding: 1rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
}

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

.size-item.selected {
    border-color: var(--primary);
    background: var(--surface-hover);
}

.size-item input[type="checkbox"] {
    margin-bottom: 0.5rem;
    width: 1.25rem;
    height: 1.25rem;
    cursor: pointer;
}

.size-item .size-label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.size-item .size-description {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.generate-btn {
    width: 100%;
    padding: 1rem 2rem;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 0.75rem;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.cancel-btn {
    width: 100%;
    padding: 0.75rem 2rem;
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border);
    border-radius: 0.75rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    margin-top: 1rem;
}

.cancel-btn:hover {
    background: var(--surface);
    color: var(--text);
    border-color: var(--text-secondary);
}

.generate-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(99, 102, 241, 0.3);
}

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

.download-section h2 {
    text-align: center;
    margin-bottom: 2rem;
}

.generated-previews {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
    background: var(--surface);
    padding: 2rem;
    border-radius: 1rem;
}

.preview-item {
    text-align: center;
    padding: 1rem;
    background: var(--bg);
    border-radius: 0.5rem;
}

.preview-item img {
    width: 64px;
    height: 64px;
    object-fit: contain;
    margin-bottom: 0.5rem;
}

.preview-item .size-text {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.download-options {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
}

.download-btn {
    flex: 1;
    padding: 1rem 2rem;
    border: none;
    border-radius: 0.75rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

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

.download-btn.primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

.download-btn:not(.primary) {
    background: var(--surface);
    color: var(--text);
    border: 1px solid var(--border);
}

.download-btn:not(.primary):hover {
    background: var(--surface-hover);
}

.code-snippet {
    background: var(--surface);
    border-radius: 1rem;
    padding: 1.5rem;
    margin-bottom: 2rem;
}

.code-snippet h3 {
    margin-bottom: 1rem;
}

.code-snippet pre {
    background: var(--bg);
    padding: 1rem;
    border-radius: 0.5rem;
    overflow-x: auto;
}

.code-snippet code {
    color: var(--success);
    font-family: 'Courier New', monospace;
    font-size: 0.875rem;
}


.reset-btn {
    width: 100%;
    padding: 0.75rem;
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    cursor: pointer;
    transition: all 0.2s;
}

.reset-btn:hover {
    background: var(--surface);
    color: var(--text);
}


.hidden {
    display: none;
}


@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }

    .header h1 {
        font-size: 2rem;
    }

    .download-options {
        flex-direction: column;
    }

    .sizes-grid {
        grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    }
}