:root {
    --color-primary: #262626;
    --color-primary-hover: #171717;
    --color-background: #fafafa;
    --color-surface: #ffffff;
    --color-text: #171717;
    --color-text-secondary: #525252;
    --color-border: #e5e5e5;
    --color-border-dark: #262626;
    --color-canvas-bg: #f5f5f5;
    --color-accent: #3b82f6;
    --color-success: #10b981;
    --color-warning: #f59e0b;
    
    --shadow-sm: 0 0.125rem 0.25rem rgba(0, 0, 0, 0.06);
    --shadow-md: 0 0.5rem 1rem rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 1rem 3rem rgba(0, 0, 0, 0.1);
    
    --radius-sm: 0.375rem;
    --radius-md: 0.625rem;
    --radius-lg: 1rem;
    
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --transition: all 0.2s ease;
}

[data-theme="dark"] {
    --color-primary: #d4d4d4;
    --color-primary-hover: #e5e5e5;
    --color-background: #0a0a0a;
    --color-surface: #171717;
    --color-text: #e5e5e5;
    --color-text-secondary: #a3a3a3;
    --color-border: #404040;
    --color-border-dark: #737373;
    --color-canvas-bg: #0a0a0a;
    --color-accent: #60a5fa;
    --color-success: #34d399;
    --color-warning: #fbbf24;
    
    --shadow-sm: 0 0.125rem 0.25rem rgba(0, 0, 0, 0.5);
    --shadow-md: 0 0.5rem 1rem rgba(0, 0, 0, 0.5);
    --shadow-lg: 0 1rem 3rem rgba(0, 0, 0, 0.5);
}

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

body {
    font-family: var(--font-family);
    background-color: var(--color-background);
    color: var(--color-text);
    line-height: 1.6;
    font-size: 16px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.loader {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 50px;
    height: 50px;
    border: 3px solid var(--color-border);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    z-index: 1000;
    display: none;
}

.loader.active {
    display: block;
}

@keyframes spin {
    to { transform: translate(-50%, -50%) rotate(360deg); }
}

.header {
    background-color: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: var(--transition);
}

.header__container {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--space-md) var(--space-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header__logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    transition: var(--transition);
}

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

.header__logo svg {
    width: 2rem;
    height: 2rem;
    fill: currentColor;
}

.header__nav {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
}

.mode-toggle {
    background-color: var(--color-accent);
    color: white;
    border: none;
    padding: var(--space-xs) var(--space-md);
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
}

.mode-toggle:hover {
    opacity: 0.9;
}

.theme-toggle {
    background-color: var(--color-background);
    border: 2px solid var(--color-border-dark);
    width: 2.5rem;
    height: 2.5rem;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

.theme-toggle:hover {
    background-color: var(--color-surface);
    opacity: 0.9;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--space-xl);
}

.hero {
    text-align: center;
    margin-bottom: var(--space-2xl);
    transition: var(--transition);
}

.hero.hidden {
    display: none;
}

.hero__title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--space-md);
    color: var(--color-text);
}

.hero__subtitle {
    font-size: 1.25rem;
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

.upload {
    background-color: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    margin-bottom: var(--space-xl);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.upload.hidden {
    display: none;
}

.upload__grid {
    display: flex;
    justify-content: center;
    gap: var(--space-md);
    flex-wrap: wrap;
}

.upload__button {
    flex-grow: 1;
    flex-basis: 300px;
    max-width: 450px;
    padding: var(--space-lg) var(--space-xl);
    background-color: var(--color-background);
    border: 2px solid var(--color-border-dark);
    border-radius: var(--radius-md);
    color: var(--color-primary);
    font-size: 1.125rem;
    font-weight: 500;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
}

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

[data-theme="dark"] .upload__button:hover {
    background-color: var(--color-background);
}

.upload__input {
    display: none;
}

.workspace {
    display: none;
    gap: var(--space-lg);
    margin-bottom: var(--space-xl);
}

.workspace.active {
    display: grid;
    grid-template-columns: 1fr 350px;
}

.canvas-container {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    gap: var(--space-md);
}

#canvas {
    max-width: 100%;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
}

.canvas-tools {
    display: flex;
    gap: var(--space-sm);
    padding: var(--space-sm);
    background-color: var(--color-surface);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.canvas-tool {
    padding: var(--space-xs) var(--space-sm);
    background-color: var(--color-background);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 0.875rem;
    transition: var(--transition);
    color: var(--color-text);
}

.canvas-tool:hover {
    background-color: var(--color-border);
}

[data-theme="dark"] .canvas-tool:hover {
    background-color: var(--color-surface);
    border-color: var(--color-border-dark);
}

.canvas-tool.active {
    background-color: var(--color-accent);
    color: white;
    border-color: var(--color-accent);
}

.controls {
    background-color: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    box-shadow: var(--shadow-sm);
    max-height: 80vh;
    overflow-y: auto;
}

.control-section {
    margin-bottom: var(--space-xl);
}

.control-section.advanced {
    display: none;
}

.control-section.advanced.active {
    display: block;
}

.control__label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 500;
    margin-bottom: var(--space-md);
    color: var(--color-text);
}

.control__value {
    font-weight: 400;
    color: var(--color-text-secondary);
}

.control__slider {
    width: 100%;
    height: 0.5rem;
    -webkit-appearance: none;
    appearance: none;
    background-color: var(--color-border);
    border-radius: var(--radius-sm);
    outline: none;
    transition: var(--transition);
}

.control__slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 1.5rem;
    height: 1.5rem;
    background-color: var(--color-surface);
    border: 2px solid var(--color-primary);
    border-radius: 50%;
    cursor: pointer;
    transition: var(--transition);
}

.control__slider::-webkit-slider-thumb:hover {
    box-shadow: 0 0 0 0.25rem rgba(59, 130, 246, 0.1);
}

[data-theme="dark"] .control__slider::-webkit-slider-thumb {
    background-color: var(--color-primary);
    border-color: var(--color-primary);
}

[data-theme="dark"] .control__slider::-webkit-slider-thumb:hover {
    box-shadow: 0 0 0 0.25rem rgba(96, 165, 250, 0.2);
}

.control__slider::-moz-range-thumb {
    width: 1.5rem;
    height: 1.5rem;
    background-color: var(--color-surface);
    border: 2px solid var(--color-primary);
    border-radius: 50%;
    cursor: pointer;
}

.control__input {
    width: 100%;
    padding: var(--space-sm);
    background-color: var(--color-background);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-text);
    font-size: 0.875rem;
}

.control__select {
    width: 100%;
    padding: var(--space-sm);
    background-color: var(--color-background);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-text);
    font-size: 0.875rem;
    cursor: pointer;
}

[data-theme="dark"] .control__select option {
    background-color: var(--color-surface);
    color: var(--color-text);
}

.position-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-sm);
    margin-bottom: var(--space-md);
}

.position-input {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

.position-input label {
    font-weight: 500;
    color: var(--color-text-secondary);
    width: 20px;
}

.position-input input {
    flex: 1;
}

.alignment-tools {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-xs);
    margin-bottom: var(--space-md);
}

.alignment-btn {
    padding: var(--space-sm);
    background-color: var(--color-background);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.875rem;
    color: var(--color-text);
}

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

[data-theme="dark"] .alignment-btn:hover {
    background-color: var(--color-surface);
    border-color: var(--color-border-dark);
}

.layers-section {
    margin-bottom: var(--space-xl);
    display: none;
}

.layers-section.active {
    display: block;
}

.layers-title {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
    color: var(--color-text);
}

.layers-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.layer-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm);
    background-color: var(--color-background);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
}

.layer-item:hover {
    background-color: var(--color-border);
}

[data-theme="dark"] .layer-item:hover {
    background-color: rgba(255, 255, 255, 0.05);
}

.layer-item.active {
    background-color: var(--color-accent);
    color: white;
}

.layer-item.active .layer-name {
    color: white;
}

.layer-visibility {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    padding: var(--space-xs);
    opacity: 0.7;
    transition: var(--transition);
}

.layer-visibility:hover {
    opacity: 1;
}

.layer-name {
    flex: 1;
    font-size: 0.875rem;
    color: var(--color-text);
}

.layer-actions {
    display: flex;
    gap: var(--space-xs);
}

.layer-action {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 0.875rem;
    padding: var(--space-xs);
    opacity: 0.7;
    transition: var(--transition);
    color: var(--color-text);
}

.layer-action:hover {
    opacity: 1;
}

.layer-delete {
    color: #ef4444;
}

.action-button {
    display: block;
    width: 100%;
    padding: var(--space-md);
    background-color: var(--color-background);
    border: 2px solid var(--color-border-dark);
    border-radius: var(--radius-md);
    color: var(--color-primary);
    font-size: 0.875rem;
    font-weight: 500;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    margin-bottom: var(--space-md);
}

.action-button:hover {
    background-color: var(--color-surface);
    border-color: var(--color-primary);
}

[data-theme="dark"] .action-button:hover {
    background-color: var(--color-background);
}

.action-button.primary {
    background-color: var(--color-accent);
    color: white;
    border-color: var(--color-accent);
}

.action-button.primary:hover {
    opacity: 0.9;
}

.instructions {
    background-color: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    margin-bottom: var(--space-xl);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.instructions.hidden {
    display: none;
}

.instructions__title {
    font-size: 1.75rem;
    margin-bottom: var(--space-lg);
    text-align: center;
    color: var(--color-text);
}

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

.instructions__item {
    display: flex;
    align-items: flex-start;
    margin-bottom: var(--space-md);
}

.instructions__number {
    background-color: var(--color-primary);
    color: var(--color-surface);
    width: 2rem;
    height: 2rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    margin-right: var(--space-md);
    flex-shrink: 0;
}

[data-theme="dark"] .instructions__number {
    background-color: var(--color-primary);
    color: var(--color-background);
}

.instructions__text {
    color: var(--color-text-secondary);
    line-height: 1.8;
}

.features {
    margin-bottom: var(--space-2xl);
}

.features__title {
    font-size: 1.75rem;
    text-align: center;
    margin-bottom: var(--space-xl);
    color: var(--color-text);
}

.features__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-lg);
}

.feature {
    background-color: var(--color-surface);
    padding: var(--space-lg);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    text-align: center;
    transition: var(--transition);
}

.feature:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.feature__icon {
    font-size: 2rem;
    margin-bottom: var(--space-sm);
}

.feature__title {
    font-size: 1.125rem;
    margin-bottom: var(--space-xs);
    color: var(--color-primary);
    font-weight: 600;
}

.feature__description {
    color: var(--color-text-secondary);
    font-size: 0.9rem;
    line-height: 1.5;
}

.use-cases {
    margin-bottom: var(--space-2xl);
}

.use-cases__title {
    font-size: 1.75rem;
    text-align: center;
    margin-bottom: var(--space-xl);
    color: var(--color-text);
}

.use-cases__grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-lg);
}

.use-case {
    background-color: var(--color-surface);
    padding: var(--space-lg);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    text-align: center;
    transition: var(--transition);
}

.use-case:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.use-case__icon {
    font-size: 2.5rem;
    margin-bottom: var(--space-sm);
}

.use-case__title {
    font-size: 1.125rem;
    margin-bottom: var(--space-xs);
    color: var(--color-primary);
    font-weight: 600;
}

.use-case__description {
    color: var(--color-text-secondary);
    font-size: 0.9rem;
    line-height: 1.5;
}

.faq-section {
    margin-bottom: var(--space-2xl);
}

.faq-section__title {
    font-size: 1.75rem;
    text-align: center;
    margin-bottom: var(--space-xl);
    color: var(--color-text);
}

.faq-container {
    max-width: 700px;
    margin: 0 auto;
}

.faq-item {
    background-color: var(--color-surface);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-md);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.faq-question {
    width: 100%;
    padding: var(--space-md);
    background: none;
    border: none;
    text-align: left;
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-text);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
}

.faq-question:hover {
    background-color: var(--color-background);
}

.faq-question::after {
    content: '+';
    font-size: 1.25rem;
    color: var(--color-accent);
    transition: transform 0.3s ease;
}

.faq-item.active .faq-question::after {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.faq-item.active .faq-answer {
    max-height: 300px;
}

.faq-answer-content {
    padding: 0 var(--space-md) var(--space-md);
    color: var(--color-text-secondary);
    font-size: 0.9rem;
    line-height: 1.5;
}

.footer {
    background-color: var(--color-surface);
    border-top: 1px solid var(--color-border);
    padding: var(--space-xl);
    padding-bottom: var(--space-2xl);
    text-align: center;
    margin-top: var(--space-2xl);
    transition: var(--transition);
}

.footer__links {
    display: flex;
    justify-content: center;
    gap: var(--space-xl);
    margin-bottom: var(--space-md);
}

.footer__link {
    color: var(--color-text-secondary);
    text-decoration: none;
    transition: var(--transition);
}

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

@media (max-width: 1024px) {
    .workspace.active {
        grid-template-columns: 1fr;
    }

    .controls {
        order: 2;
    }

    .canvas-container {
        order: 1;
    }
    
    .use-cases__grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 768px) {
    .hero__title {
        font-size: 2rem;
    }

    .upload__grid {
        grid-template-columns: 1fr;
    }


    .container {
        padding: var(--space-md);
    }

    .header__container {
        padding: var(--space-md);
    }

    .header__logo span {
        display: none;
    }

    .alignment-tools {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .use-cases__grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--space-md);
    }
    
    .use-case {
        padding: var(--space-md);
    }
    
    .use-case__icon {
        font-size: 2rem;
    }
    
    .use-case__title {
        font-size: 1rem;
    }
    
    .use-case__description {
        font-size: 0.85rem;
    }

}