/* CSS Custom Properties for theming */
:root {
    --bg-primary: #1e1e1e;
    --bg-secondary: #252526;
    --bg-tertiary: #2d2d30;
    --bg-hover: #3e3e42;
    --text-primary: #e0e0e0;
    --text-secondary: #a0a0a0;
    --text-muted: #6e6e6e;
    --accent: #007acc;
    --accent-hover: #1a8ad4;
    --border: #3e3e42;
    --success: #4caf50;
    --warning: #ff9800;
    --error: #f44336;
    --code-bg: #1a1a1a;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.app-header {
    background: var(--bg-secondary);
    padding: 12px 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--border);
}

.app-header h1 {
    font-size: 1.25rem;
    font-weight: 600;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 10px;
}

.header-controls label {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.header-controls select {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border);
    padding: 6px 10px;
    border-radius: 4px;
    font-size: 0.9rem;
    cursor: pointer;
}

.header-controls select:hover {
    border-color: var(--accent);
}

/* Main Layout - Side by Side */
.app-main {
    display: flex;
    flex: 1;
    min-height: 0;
}

/* Editor Panel (Left) */
.editor-panel {
    flex: 1;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 15px;
    border-right: 1px solid var(--border);
    min-width: 300px;
}

.dimension-controls {
    display: flex;
    align-items: center;
    gap: 15px;
    flex-wrap: wrap;
}

.control-group {
    display: flex;
    align-items: center;
    gap: 8px;
}

.control-group label {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.control-group input[type="number"] {
    width: 60px;
    padding: 6px 10px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-primary);
    font-size: 0.9rem;
}

.control-group input[type="number"]:focus {
    outline: none;
    border-color: var(--accent);
}

/* Sizing Controls */
.sizing-controls {
    background: var(--bg-tertiary);
    border-radius: 6px;
    border: 1px solid var(--border);
}

.sizing-controls summary {
    padding: 10px 14px;
    cursor: pointer;
    font-size: 0.85rem;
    color: var(--text-secondary);
    user-select: none;
}

.sizing-controls summary:hover {
    color: var(--text-primary);
}

.sizing-controls[open] summary {
    border-bottom: 1px solid var(--border);
}

.sizing-content {
    padding: 12px 14px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.sizing-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.sizing-group > label {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.size-inputs {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.size-input-wrapper {
    display: flex;
    align-items: center;
    gap: 4px;
}

.size-input-wrapper .size-label {
    font-size: 0.7rem;
    color: var(--text-muted);
    min-width: 18px;
}

.size-input-wrapper input {
    width: 60px;
    padding: 4px 6px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 3px;
    color: var(--text-primary);
    font-size: 0.8rem;
}

.size-input-wrapper input:focus {
    outline: none;
    border-color: var(--accent);
}

/* Buttons */
.btn {
    padding: 8px 16px;
    border: none;
    border-radius: 4px;
    font-size: 0.9rem;
    cursor: pointer;
    transition: background 0.2s;
}

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

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

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background: var(--bg-hover);
}

.btn-copy {
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border);
    padding: 4px 10px;
    font-size: 0.8rem;
}

.btn-copy:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

/* Grid Editor */
.grid-editor-container {
    flex: 1;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding: 10px;
    background: var(--bg-tertiary);
    border-radius: 8px;
    min-height: 200px;
    overflow: auto;
}

.grid-editor {
    display: grid;
    gap: 0;
    background: var(--bg-secondary);
    border-radius: 4px;
    border: 1px solid var(--border);
}

.grid-cell {
    width: 80px;
    height: 60px;
    background: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 0.75rem;
    color: var(--text-secondary);
    transition: background 0.15s, border-color 0.15s;
    border: 1px solid var(--border);
    position: relative;
}

.grid-cell:hover {
    background: var(--bg-hover);
    border-color: var(--accent);
}

.grid-cell.selecting {
    border-color: var(--preview-color, var(--accent)) !important;
    box-shadow: inset 0 0 0 2px var(--preview-color, var(--accent));
    background-color: var(--preview-color, var(--bg-hover)) !important;
    opacity: 0.75;
}

.grid-cell.selecting .cell-label {
    color: white;
    text-shadow: 0 1px 2px rgba(0,0,0,0.5);
}

.grid-cell.named {
    color: white;
    font-weight: 500;
}

.grid-cell .cell-label {
    text-align: center;
    word-break: break-word;
    padding: 4px;
    max-width: 100%;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* Border merging for same-named adjacent cells */
.grid-cell.merge-top {
    border-top-color: transparent !important;
}

.grid-cell.merge-right {
    border-right-color: transparent !important;
}

.grid-cell.merge-bottom {
    border-bottom-color: transparent !important;
}

.grid-cell.merge-left {
    border-left-color: transparent !important;
}

.editor-instructions {
    font-size: 0.85rem;
    color: var(--text-muted);
    text-align: center;
}

/* Validation Messages */
.validation-messages {
    min-height: 24px;
}

.validation-error {
    background: rgba(244, 67, 54, 0.1);
    border: 1px solid var(--error);
    color: var(--error);
    padding: 8px 12px;
    border-radius: 4px;
    font-size: 0.85rem;
}

.validation-success {
    background: rgba(76, 175, 80, 0.1);
    border: 1px solid var(--success);
    color: var(--success);
    padding: 8px 12px;
    border-radius: 4px;
    font-size: 0.85rem;
}

/* Preview Panel (Right) */
.preview-panel {
    flex: 1;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 15px;
    min-width: 300px;
}

.preview-panel h2 {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.live-preview {
    flex: 1;
    background: var(--bg-tertiary);
    border-radius: 8px;
    padding: 15px;
    min-height: 200px;
}

.preview-grid {
    display: grid;
    gap: 10px;
    height: 100%;
    min-height: 250px;
}

.preview-area {
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 4px;
    font-weight: 500;
    font-size: 0.9rem;
    color: white;
    text-shadow: 0 1px 2px rgba(0,0,0,0.3);
    min-height: 40px;
}

/* Code Panel (Bottom) */
.code-panel {
    display: flex;
    gap: 20px;
    padding: 20px;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    max-height: 300px;
}

.code-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 8px;
    min-width: 0;
}

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

.code-header h3 {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.code-output {
    flex: 1;
    background: var(--code-bg);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 12px;
    overflow: auto;
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 0.8rem;
    line-height: 1.5;
    white-space: pre;
    color: var(--text-primary);
}

.code-output code {
    display: block;
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.6);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.modal[hidden] {
    display: none;
}

.modal-content {
    background: var(--bg-secondary);
    padding: 24px;
    border-radius: 8px;
    border: 1px solid var(--border);
    min-width: 300px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.modal-content label {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.modal-content input[type="text"] {
    width: 100%;
    padding: 10px 12px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-primary);
    font-size: 1rem;
}

.modal-content input[type="text"]:focus {
    outline: none;
    border-color: var(--accent);
}

.modal-buttons {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
}

/* Responsive adjustments */
@media (max-width: 900px) {
    .app-main {
        flex-direction: column;
    }

    .editor-panel {
        border-right: none;
        border-bottom: 1px solid var(--border);
    }

    .code-panel {
        flex-direction: column;
        max-height: none;
    }

    .code-output {
        max-height: 200px;
    }
}

@media (max-width: 500px) {
    .app-header {
        flex-direction: column;
        gap: 10px;
        align-items: flex-start;
    }

    .dimension-controls {
        flex-direction: column;
        align-items: stretch;
    }

    .control-group {
        justify-content: space-between;
    }

    .grid-cell {
        width: 60px;
        height: 50px;
        font-size: 0.65rem;
    }
}