/**
 * Canvas styles - canvas container, grid, hints, drop zones
 */

/* Canvas Container */
#canvas-container {
    position: fixed;
    top: var(--toolbar-height);
    left: 0;
    right: 0;
    bottom: var(--input-height);
    overflow: hidden;
    cursor: grab;
}

#canvas-container:active {
    cursor: grabbing;
}

#canvas {
    width: 100%;
    height: 100%;
    background: var(--bg-canvas);
}

/* Grid pattern for canvas (subtle) */
#canvas {
    background-image:
        radial-gradient(circle, var(--edge-color-light) 1px, transparent 1px);
    background-size: 24px 24px;
    background-position: center center;
}

/* Hint overlay when no nodes visible */
.no-nodes-hint {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.5s ease-in;
}

.no-nodes-hint.visible {
    opacity: 1;
}

.no-nodes-hint .hint-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    padding: 24px 32px;
    background: var(--bg-primary);
    border: 1px solid var(--bg-secondary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

.no-nodes-hint .hint-icon {
    font-size: 32px;
}

.no-nodes-hint .hint-text {
    color: var(--text-secondary);
    font-size: 14px;
    text-align: center;
}

/* Drop zone overlay for PDF drag & drop */
.drop-zone-overlay {
    position: absolute;
    inset: 0;
    background: rgba(34, 139, 230, 0.1);
    border: 3px dashed var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 50;
    pointer-events: none;
}

.drop-zone-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    padding: 24px 48px;
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

.drop-zone-icon {
    font-size: 48px;
}

.drop-zone-text {
    font-size: 18px;
    font-weight: 500;
    color: var(--text-primary);
}

/* Canvas hint notification */
#canvas-hint {
    position: fixed;
    bottom: 80px;
    left: 50%;
    transform: translateX(-50%) translateY(20px);
    padding: 12px 24px;
    background: var(--bg-primary);
    border: 1px solid var(--bg-secondary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    font-size: 14px;
    color: var(--text-primary);
    z-index: 200;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease, transform 0.3s ease;
}

#canvas-hint.visible {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* Edges */
.edge {
    fill: none;
    stroke: var(--edge-color);
    stroke-width: 2;
    stroke-linecap: round;
}

.edge.highlight {
    stroke: var(--node-highlight-border);
    stroke-width: 2;
    stroke-dasharray: 8, 4;
}

.edge.context-highlight {
    stroke: var(--selection-color);
    stroke-width: 3;
}

.edge-arrow {
    fill: var(--edge-color);
}
