:root {
    --bg: #0f172a;
    --panel-bg: #1e293b;
    --line: #e2e8f0;
    --accent: #38bdf8;
    --danger: #f87171;
    --text: #e2e8f0;
    --grid: #1e293b;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: system-ui, sans-serif;
    background: var(--bg);
    color: var(--text);
    height: 100vh;
    display: flex;
    flex-direction: column;
}

.topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 16px;
    background: var(--panel-bg);
    border-bottom: 1px solid #334155;
}

.topbar h1 {
    font-size: 16px;
    margin: 0;
}

.topbar-actions button {
    margin-left: 8px;
    padding: 6px 12px;
    background: #334155;
    color: var(--text);
    border: 1px solid #475569;
    border-radius: 6px;
    cursor: pointer;
    font-size: 13px;
}

.topbar-actions button:hover {
    background: #475569;
}

.topbar-actions button.danger {
    background: #7f1d1d;
    border-color: #991b1b;
}

.app {
    flex: 1;
    display: grid;
    grid-template-columns: 220px 1fr 240px;
    min-height: 0;
}

.panel {
    background: var(--panel-bg);
    padding: 12px;
    overflow-y: auto;
}

.panel h2 {
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: #94a3b8;
    margin: 0 0 10px;
}

.palette-item {
    padding: 8px 10px;
    margin-bottom: 6px;
    background: #334155;
    border-radius: 6px;
    cursor: grab;
    font-size: 13px;
}

.palette-item:hover {
    background: #475569;
}

.hint {
    font-size: 12px;
    color: #94a3b8;
    margin-top: 16px;
    line-height: 1.4;
}

.canvas-wrap {
    position: relative;
    overflow: hidden;
    background-color: var(--bg);
    background-image:
        linear-gradient(var(--grid) 1px, transparent 1px),
        linear-gradient(90deg, var(--grid) 1px, transparent 1px);
    background-size: 24px 24px;
    cursor: grab;
}

.canvas-layer {
    position: absolute;
    top: 0;
    left: 0;
    transform-origin: 0 0;
}

#device-layer {
    z-index: 2;
}

.wire-svg {
    width: 100%;
    height: 100%;
    overflow: visible;
    pointer-events: none;
    z-index: 1;
}

.wire-svg .wire-group {
    pointer-events: auto;
}

.wire {
    fill: none;
    stroke: var(--accent);
    stroke-width: 2;
}

.wire.wire-pending {
    stroke-dasharray: 4 3;
}

.wire-hit {
    fill: none;
    stroke: transparent;
    stroke-width: 12;
    cursor: pointer;
}

.wire-group.selected .wire {
    stroke: var(--danger);
    stroke-width: 3;
}

.device-node {
    position: absolute;
    cursor: grab;
}

.device-node.selected .symbol .body-line,
.device-node.selected .symbol .board-outline,
.device-node.selected .symbol .module-outline {
    stroke: var(--danger);
}

.device-body {
    color: var(--text);
}

.symbol {
    overflow: visible;
}

.symbol .lead,
.symbol .body-line {
    stroke: var(--line);
    stroke-width: 2;
    fill: none;
}

.symbol .body-fill {
    fill: var(--line);
    stroke: var(--line);
}

.symbol .light-arrow {
    stroke: #fbbf24;
    stroke-width: 1.5;
    fill: none;
}

.symbol .value-label {
    fill: #94a3b8;
    font-size: 11px;
}

.symbol .board-outline,
.symbol .module-outline {
    fill: none;
    stroke: var(--line);
    stroke-width: 2;
}

.symbol .board-title,
.symbol .module-title {
    fill: var(--text);
    font-size: 13px;
    font-weight: 600;
    dominant-baseline: middle;
}

.symbol .pin-label {
    fill: #94a3b8;
    font-size: 9px;
}

.device-label {
    position: absolute;
    top: -16px;
    left: 0;
    font-size: 11px;
    color: #94a3b8;
    white-space: nowrap;
}

.ports-layer {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

.port-group {
    position: absolute;
    transform: translate(-50%, -50%);
    pointer-events: none;
}

.port {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--accent);
    border: 2px solid #0f172a;
    cursor: crosshair;
    pointer-events: auto;
}

.port:hover {
    background: #7dd3fc;
}

.port-label {
    position: absolute;
    font-size: 9px;
    color: #94a3b8;
    white-space: nowrap;
    background: var(--bg);
    padding: 1px 4px;
    border-radius: 3px;
    line-height: 1.3;
}

.side-left .port-label {
    left: 12px;
    top: 50%;
    transform: translateY(-50%);
}

.side-right .port-label {
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    text-align: right;
}

.side-top .port-label {
    left: 50%;
    bottom: 12px;
    transform: translateX(-50%);
}

.side-bottom .port-label {
    left: 50%;
    top: 12px;
    transform: translateX(-50%);
}

.inspector-empty {
    font-size: 12px;
    color: #64748b;
}

.inspector-field {
    display: block;
    font-size: 12px;
    color: #94a3b8;
    margin-bottom: 12px;
}

.inspector-field input {
    display: block;
    width: 100%;
    margin-top: 4px;
    padding: 6px 8px;
    background: #0f172a;
    border: 1px solid #334155;
    border-radius: 4px;
    color: var(--text);
    font-size: 13px;
}

.inspector-delete {
    width: 100%;
    padding: 8px;
    background: #7f1d1d;
    border: 1px solid #991b1b;
    border-radius: 6px;
    color: var(--text);
    cursor: pointer;
}