:root {
    --bg-color: #1a1c1e;
    --surface-color: #2c2f33;
    --primary-color: #a8c7fa;
    --on-primary-color: #003366;
    --text-color: #e2e2e6;
    --text-muted-color: #8f9196;
    --outline-color: #44474c;
    --danger-color: #f2b8b5;
    --radius: 12px;
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

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

html, body {
    height: 100%;
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-color);
    font-size: 14px;
    line-height: 1.5;
    overflow: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.app-container {
    display: grid;
    grid-template-columns: 320px 1fr;
    height: 100vh;
}

/* Controls Panel */
.controls-panel {
    background-color: var(--surface-color);
    padding: 24px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.app-header h1 {
    font-size: 24px;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 16px;
}

.control-section h2 {
    font-size: 16px;
    font-weight: 500;
    color: var(--text-muted-color);
    margin-bottom: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.add-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    background-color: var(--bg-color);
    border: 1px solid var(--outline-color);
    border-radius: 8px;
    color: var(--text-color);
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.2s ease;
}
.add-btn:hover {
    background-color: var(--outline-color);
}
.add-btn svg {
    stroke: var(--primary-color);
    stroke-width: 2px;
}

/* Layers List */
.layers-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
    min-height: 50px;
    border: 1px dashed var(--outline-color);
    border-radius: var(--radius);
    padding: 8px;
}

.layer-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px;
    background-color: var(--bg-color);
    border: 2px solid transparent;
    border-radius: 8px;
    cursor: grab;
    transition: all 0.2s ease;
}
.layer-item.active {
    border-color: var(--primary-color);
    background-color: rgba(168, 199, 250, 0.1);
}
.layer-item:hover {
    background-color: #3a3d41;
}
.layer-item .layer-icon {
    width: 24px;
    height: 24px;
    color: var(--text-muted-color);
    flex-shrink: 0;
}
.layer-item.active .layer-icon {
    color: var(--primary-color);
}
.layer-item .layer-name {
    flex-grow: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.layer-item .delete-layer-btn {
    background: none;
    border: none;
    color: var(--text-muted-color);
    cursor: pointer;
    padding: 4px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}
.layer-item .delete-layer-btn:hover {
    color: var(--danger-color);
    background-color: rgba(242, 184, 181, 0.1);
}
.layer-item .delete-layer-btn svg {
    width: 16px;
    height: 16px;
    stroke: currentColor;
    stroke-width: 2px;
}

.layer-controls.hidden {
    display: none;
}

/* Color Controls */
.color-control-wrapper {
    margin-bottom: 16px;
}
.color-control-wrapper label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-color);
}
.color-picker-group {
    display: flex;
    gap: 8px;
    margin-bottom: 12px;
}
.color-picker-group input[type="color"] {
    -webkit-appearance: none; -moz-appearance: none; appearance: none;
    width: 48px; height: 40px; background-color: transparent;
    border: 1px solid var(--outline-color); border-radius: 8px; cursor: pointer;
    flex-shrink: 0;
}
.color-picker-group input[type="color"]::-webkit-color-swatch-wrapper { padding: 0; }
.color-picker-group input[type="color"]::-webkit-color-swatch { border: none; border-radius: 7px; }

.hex-input {
    flex-grow: 1;
    padding: 8px; background-color: var(--bg-color);
    border: 1px solid var(--outline-color); color: var(--text-color);
    border-radius: 8px; font-family: monospace; font-size: 1em;
    text-transform: uppercase;
}

.color-palette {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(28px, 1fr));
    gap: 8px;
}
.color-swatch {
    width: 100%;
    aspect-ratio: 1 / 1;
    border-radius: 50%;
    border: 2px solid transparent;
    cursor: pointer;
    transition: all 0.2s ease;
}
.color-swatch:hover {
    transform: scale(1.1);
}
.color-swatch.active {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px var(--bg-color), 0 0 0 4px var(--primary-color);
}

/* Sliders */
.slider-group {
    margin-bottom: 16px;
    display: grid;
    grid-template-columns: 1fr auto;
    align-items: center;
    gap: 12px;
}
.slider-group label { display: block; grid-column: 1 / -1; margin-bottom: 4px; color: var(--text-color); }
.slider-group input[type="range"] {
    -webkit-appearance: none; appearance: none; width: 100%; height: 6px;
    background: var(--bg-color); border-radius: 3px; outline: none; cursor: pointer;
}
.slider-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none; appearance: none; width: 20px; height: 20px;
    background: var(--primary-color); border-radius: 50%;
    border: 3px solid var(--surface-color); transition: transform 0.1s ease;
}
.slider-group input[type="range"]:active::-webkit-slider-thumb { transform: scale(1.1); }
.slider-value { font-family: monospace; font-size: 1em; color: var(--text-muted-color); }

/* Export Controls */
.export-controls { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 12px; margin-bottom: 16px; }
.export-btn {
    padding: 12px; font-size: 1em; font-weight: 500; border: 1px solid var(--outline-color);
    background-color: transparent; color: var(--text-color); border-radius: var(--radius);
    cursor: pointer; transition: background-color 0.2s ease;
}
.export-btn:hover { background-color: var(--outline-color); }
.export-btn.primary { background-color: var(--primary-color); color: var(--on-primary-color); border-color: var(--primary-color); }
.export-btn.primary:hover { filter: brightness(1.1); }
.export-size { display: flex; align-items: center; gap: 8px; }
.export-size label { color: var(--text-muted-color); }
.export-size input[type="number"] {
    width: 80px; padding: 8px; background-color: var(--bg-color);
    border: 1px solid var(--outline-color); color: var(--text-color);
    border-radius: 8px; text-align: center; -moz-appearance: textfield;
}
.export-size input[type="number"]::-webkit-outer-spin-button,
.export-size input[type="number"]::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
.export-size span { color: var(--text-muted-color); }

/* Preview Panel */
.preview-panel { display: flex; justify-content: center; align-items: center; padding: 32px; overflow: hidden; }
#pattern-canvas {
    width: 100%; height: 100%; object-fit: contain;
    background-color: var(--surface-color); box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    border-radius: var(--radius);
}

/* Modal */
.modal-overlay {
    position: fixed; top: 0; left: 0; width: 100%; height: 100%;
    background-color: rgba(0, 0, 0, 0.6); backdrop-filter: blur(8px);
    display: flex; justify-content: center; align-items: center;
    z-index: 1000; opacity: 1; transition: opacity 0.3s ease;
}
.modal-overlay.hidden {
    opacity: 0; pointer-events: none;
}
.modal-content {
    background-color: var(--surface-color);
    border-radius: var(--radius);
    padding: 24px;
    width: 90%;
    max-width: 600px;
    max-height: 80vh;
    display: flex;
    flex-direction: column;
    box-shadow: 0 10px 30px rgba(0,0,0,0.3);
}
.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}
.modal-header h2 { margin: 0; }
.close-btn {
    background: none; border: none; color: var(--text-muted-color);
    cursor: pointer; padding: 4px; border-radius: 50%;
}
.close-btn:hover { color: var(--text-color); background-color: var(--outline-color); }
.close-btn svg { stroke: currentColor; stroke-width: 2px; }

/* Pattern Grid in Modal */
.pattern-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
    gap: 16px;
    overflow-y: auto;
    padding-right: 12px; /* For scrollbar */
}
.pattern-grid-btn {
    display: flex; flex-direction: column; align-items: center; justify-content: center;
    gap: 8px; aspect-ratio: 1 / 1; background-color: var(--bg-color);
    border: 2px solid transparent; border-radius: var(--radius);
    color: var(--text-muted-color); cursor: pointer; transition: all 0.2s ease;
}
.pattern-grid-btn:hover { border-color: var(--primary-color); color: var(--primary-color); }
.pattern-grid-btn svg { width: 36px; height: 36px; }
.pattern-grid-btn span { font-size: 12px; text-transform: capitalize; }


/* Responsive Design */
@media (max-width: 768px) {
    body {
        overflow: auto;
    }
    .app-container {
        grid-template-columns: 1fr;
        grid-template-rows: auto 1fr;
        height: 100%;
        min-height: 100vh;
    }
    .controls-panel {
        padding: 16px;
        border-bottom: 1px solid var(--outline-color);
        overflow-y: visible; /* Let the body scroll */
    }
    .preview-panel {
        height: 60vh;
        min-height: 300px;
        padding: 16px;
    }
    .app-header h1 {
        font-size: 20px;
        margin-bottom: 8px;
    }
    .control-section {
        margin-bottom: 16px;
    }
    .modal-content {
        max-height: 90vh;
        width: 95%;
    }
    .pattern-grid {
        grid-template-columns: repeat(auto-fill, minmax(70px, 1fr));
        gap: 12px;
    }
}