/* ============================================================
   Canvas Styles
   ============================================================ */

/* ── Toolbar ───────────────────────────────────────────────── */

.canvas-section {
    position: relative;
}

.canvas-toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 16px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md) var(--radius-md) 0 0;
    gap: 12px;
    flex-wrap: wrap;
}

.toolbar-left,
.toolbar-center,
.toolbar-right {
    display: flex;
    align-items: center;
    gap: 6px;
}

.toolbar-separator {
    width: 1px;
    height: 24px;
    background: var(--border-strong);
    margin: 0 4px;
}

.toolbar-btn {
    background: none;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 6px 10px;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    transition: background 0.12s, border-color 0.12s;
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

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

.toolbar-btn.active {
    background: rgba(63, 81, 181, 0.08);
    border-color: var(--primary-light);
    color: var(--primary);
}

.toolbar-label {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.toolbar-select {
    padding: 6px 10px;
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-sm);
    font-size: 0.8rem;
    font-family: inherit;
    color: var(--text);
    background: var(--surface);
    cursor: pointer;
}

.toolbar-select:focus {
    outline: none;
    border-color: var(--primary-light);
}

.graph-title-display {
    font-weight: 700;
    font-size: 0.95rem;
    color: var(--text);
    max-width: 200px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* ── Canvas Container ──────────────────────────────────────── */

.canvas-container {
    position: relative;
    width: 100%;
    height: calc(100vh - 180px);
    min-height: 500px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-top: none;
    border-radius: 0 0 var(--radius-md) var(--radius-md);
    overflow: hidden;
    cursor: default;
}

.canvas-container.cursor-crosshair { cursor: crosshair; }
.canvas-container.cursor-grab { cursor: grab; }
.canvas-container.cursor-grabbing { cursor: grabbing; }
.canvas-container.cursor-pointer { cursor: pointer; }

.canvas-bg-layer,
.canvas-svg-layer,
.canvas-box-layer {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
}

.canvas-bg-layer {
    z-index: 1;
    pointer-events: none;
}

.canvas-bg-layer.interactive {
    pointer-events: auto;
}

.canvas-svg-layer {
    z-index: 2;
    pointer-events: none;
}

.canvas-box-layer {
    z-index: 3;
    pointer-events: none;
}

/* ── Boxes on Canvas ───────────────────────────────────────── */

.canvas-box {
    position: absolute;
    background: var(--surface);
    border: 2px solid var(--primary-light);
    border-radius: var(--radius-md);
    padding: 10px 14px;
    min-width: 120px;
    min-height: 60px;
    cursor: move;
    pointer-events: auto;
    box-shadow: var(--shadow-sm);
    transition: box-shadow 0.15s;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.canvas-box:hover {
    box-shadow: var(--shadow-md);
}

.canvas-box.selected {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(63, 81, 181, 0.15), var(--shadow-md);
}

.canvas-box .box-label {
    font-weight: 700;
    font-size: 0.85rem;
    color: var(--text);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.canvas-box .box-desc {
    font-size: 0.75rem;
    color: var(--muted);
    overflow: hidden;
    text-overflow: ellipsis;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}

.canvas-box .box-resize-handle {
    position: absolute;
    right: 0;
    bottom: 0;
    width: 14px;
    height: 14px;
    cursor: nwse-resize;
    opacity: 0;
    transition: opacity 0.15s;
}

.canvas-box:hover .box-resize-handle,
.canvas-box.selected .box-resize-handle {
    opacity: 0.5;
}

.box-resize-handle::after {
    content: "";
    position: absolute;
    right: 3px;
    bottom: 3px;
    width: 8px;
    height: 8px;
    border-right: 2px solid var(--muted);
    border-bottom: 2px solid var(--muted);
}

/* ── Connection Anchor Points ──────────────────────────────── */

.canvas-box .connection-anchor {
    position: absolute;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--accent);
    border: 2px solid var(--surface);
    box-shadow: 0 0 0 1px var(--accent);
    opacity: 0;
    transition: opacity 0.15s;
    cursor: crosshair;
    z-index: 5;
}

.canvas-box:hover .connection-anchor,
.canvas-box.selected .connection-anchor {
    opacity: 1;
}

.connection-anchor.anchor-top    { top: -5px; left: 50%; transform: translateX(-50%); }
.connection-anchor.anchor-right  { top: 50%; right: -5px; transform: translateY(-50%); }
.connection-anchor.anchor-bottom { bottom: -5px; left: 50%; transform: translateX(-50%); }
.connection-anchor.anchor-left   { top: 50%; left: -5px; transform: translateY(-50%); }

/* ── SVG Connections ───────────────────────────────────────── */

.canvas-svg-layer line,
.canvas-svg-layer path {
    pointer-events: stroke;
    cursor: pointer;
}

.canvas-svg-layer .connection-line {
    stroke: var(--muted);
    stroke-width: 2;
    fill: none;
    transition: stroke 0.15s;
}

.canvas-svg-layer .connection-line:hover {
    stroke: var(--primary);
    stroke-width: 3;
}

.canvas-svg-layer .connection-line.selected {
    stroke: var(--primary);
    stroke-width: 3;
}

.canvas-svg-layer .connection-arrow {
    fill: var(--muted);
}

.canvas-svg-layer .connection-arrow.selected {
    fill: var(--primary);
}

.canvas-svg-layer .connection-label-bg {
    fill: var(--surface);
    stroke: var(--border);
    stroke-width: 1;
    rx: 4;
}

.canvas-svg-layer .connection-label-text {
    fill: var(--text-secondary);
    font-size: 11px;
    font-weight: 600;
    font-family: inherit;
    pointer-events: auto;
    cursor: pointer;
}

/* ── Temp Connection (drawing) ─────────────────────────────── */

.canvas-svg-layer .temp-connection {
    stroke: var(--accent);
    stroke-width: 2;
    stroke-dasharray: 6 4;
    fill: none;
    pointer-events: none;
}

/* ── Grid Background Pattern ───────────────────────────────── */

.canvas-grid-bg {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(var(--border) 1px, transparent 1px),
        linear-gradient(90deg, var(--border) 1px, transparent 1px);
    background-size: 40px 40px;
    opacity: 0.5;
}

/* ── Responsive ────────────────────────────────────────────── */

@media (max-width: 700px) {
    .canvas-toolbar {
        flex-direction: column;
        align-items: flex-start;
    }
    .toolbar-center { flex-wrap: wrap; }
    .canvas-container {
        height: calc(100vh - 240px);
        min-height: 350px;
    }
}