/* styles.css */
:root {
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --card-border: #334155;
    --text-color: #f8fafc;
    --text-muted: #94a3b8;
    --accent-color: #3b82f6;
    --accent-hover: #2563eb;
    --danger-color: #ef4444;
    --success-color: #10b981;
    --grid-bg: #1e293b;
    --grid-line: #334155;
    --wall-color: #475569;
    --void-color: #020617;
    --cell-size: 40px;
}

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

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

header {
    background-color: var(--card-bg);
    border-bottom: 1px solid var(--card-border);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: #60a5fa;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

header p {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.main-container {
    display: flex;
    flex: 1;
    gap: 1.5rem;
    padding: 1.5rem;
    max-width: 1400px;
    margin: 0 auto;
    width: 100%;
}

.panel {
    background-color: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    padding: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.sidebar {
    width: 320px;
    flex-shrink: 0;
}

.workspace {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    gap: 1.5rem;
    min-width: 0;
}

.section-title {
    font-size: 1.1rem;
    font-weight: 600;
    border-bottom: 1px solid var(--card-border);
    padding-bottom: 0.5rem;
    margin-bottom: 0.5rem;
    color: #cbd5e1;
}

.tool-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.tool-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.btn {
    background-color: #334155;
    color: var(--text-color);
    border: 1px solid transparent;
    padding: 0.6rem 1rem;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 500;
    font-size: 0.9rem;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
}

.btn:hover {
    background-color: #475569;
}

.btn.active {
    background-color: var(--accent-color);
    color: #fff;
}

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

.btn-danger {
    background-color: #991b1b;
    color: #fca5a5;
}
.btn-danger:hover {
    background-color: var(--danger-color);
    color: #fff;
}

.btn-success {
    background-color: #065f46;
    color: #6ee7b7;
}
.btn-success:hover {
    background-color: var(--success-color);
    color: #fff;
}

.input-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

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

.input-group input, .input-group select {
    background-color: #0f172a;
    border: 1px solid var(--card-border);
    color: var(--text-color);
    padding: 0.4rem 0.6rem;
    border-radius: 6px;
    font-size: 0.9rem;
    width: 60px;
}

.color-picker-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.color-swatch {
    width: 28px;
    height: 28px;
    border-radius: 6px;
    cursor: pointer;
    border: 2px solid transparent;
    transition: transform 0.15s ease;
}

.color-swatch:hover {
    transform: scale(1.15);
}

.color-swatch.selected {
    border-color: #ffffff;
    box-shadow: 0 0 0 2px var(--accent-color);
}

/* Shape Preview Grid */
.shape-preview-container {
    background-color: #0f172a;
    border: 1px solid var(--card-border);
    border-radius: 8px;
    padding: 0.75rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
}

.shape-preview {
    display: grid;
    gap: 2px;
}

.shape-cell {
    width: 22px;
    height: 22px;
    border-radius: 3px;
}

.board-container {
    position: relative;
    padding: 1rem;
    background-color: #090d16;
    border: 2px solid var(--card-border);
    border-radius: 12px;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.5);
    overflow: auto;
    max-width: 100%;
}

.grid-board {
    display: grid;
    gap: 2px;
    user-select: none;
    background-color: #1e293b;
    border: 2px solid #334155;
    border-radius: 6px;
    position: relative;
}

.grid-cell {
    width: var(--cell-size);
    height: var(--cell-size);
    background-color: #0f172a;
    border-radius: 4px;
    position: relative;
    cursor: pointer;
    transition: background-color 0.15s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.grid-cell:hover {
    filter: brightness(1.2);
}

.grid-cell.tile-floor {
    background-color: #1e293b;
}

.grid-cell.tile-void {
    background-color: #020617;
    opacity: 0.4;
}

.grid-cell.tile-wall {
    background-color: #475569;
    box-shadow: inset 0 0 6px rgba(0,0,0,0.5);
}

.grid-cell.tile-gate {
    background-color: #1e293b;
    box-shadow: inset 0 0 0 4px currentColor;
    border: 2px dashed currentColor;
}

.grid-cell.tile-gate::after {
    content: 'GATE';
    font-size: 0.55rem;
    font-weight: 800;
    color: currentColor;
    letter-spacing: 0.5px;
}

/* Block Rendering */
.block-element {
    position: absolute;
    pointer-events: auto;
    cursor: move;
    transition: opacity 0.2s ease, transform 0.2s ease;
    z-index: 10;
}

.block-cell {
    position: absolute;
    width: var(--cell-size);
    height: var(--cell-size);
    box-sizing: border-box;
    transition: box-shadow 0.15s ease, filter 0.15s ease;
}

.block-id-label {
    position: absolute;
    top: 2px;
    left: 2px;
    background-color: rgba(0, 0, 0, 0.65);
    color: #ffffff;
    font-size: 0.65rem;
    font-weight: 800;
    padding: 1px 4px;
    border-radius: 3px;
    pointer-events: none;
    letter-spacing: -0.5px;
    box-shadow: 0 1px 2px rgba(0,0,0,0.5);
    z-index: 2;
}

/* Drag & Drop Feedback */
.block-cell.drag-valid {
    box-shadow: 0 0 0 3px #10b981, 0 4px 12px rgba(16, 185, 129, 0.6) !important;
    opacity: 0.9;
}

.block-cell.drag-invalid {
    box-shadow: 0 0 0 3px #ef4444, 0 4px 12px rgba(239, 68, 68, 0.6) !important;
    opacity: 0.75;
}

.block-cell.drag-delete {
    box-shadow: 0 0 0 3px #ef4444, 0 4px 12px rgba(239, 68, 68, 0.8) !important;
    opacity: 0.4;
    filter: grayscale(0.8);
}

/* Solution Controls */
.solution-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
    background-color: var(--card-bg);
    padding: 0.75rem 1.5rem;
    border-radius: 30px;
    border: 1px solid var(--card-border);
}

.step-info {
    font-size: 1rem;
    font-weight: 600;
    color: #60a5fa;
    min-width: 140px;
    text-align: center;
}

.move-description {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* Modal / Loader */
.status-indicator {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: #fbbf24;
    font-size: 0.9rem;
    font-weight: 500;
}

.spinner {
    width: 16px;
    height: 16px;
    border: 2px solid #fbbf24;
    border-top-color: transparent;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}