:root {
  font-family: ui-monospace, 'SF Mono', Menlo, Monaco, monospace;
  color-scheme: dark;
  --bg: #050507;
  --fg: #e5e5e5;
  --muted: #888;
  --dim: #555;
  --border: #1f1f26;
  --accent: #4ade80;
  --danger: #f87171;
  --panel: #0a0a10;
  --node: #0d0d13;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; }

body {
  background: radial-gradient(ellipse at top, #0a0a14 0%, var(--bg) 70%);
  color: var(--fg);
  -webkit-font-smoothing: antialiased;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  padding: 1.25rem;
  gap: 1rem;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 1rem;
  flex-wrap: wrap;
}

.brand h1 {
  font-size: clamp(1.5rem, 4vw, 2.1rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, #fff, #888);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.brand h1::before {
  content: '> ';
  color: var(--accent);
  -webkit-text-fill-color: var(--accent);
}
.home-link { text-decoration: none; display: inline-block; transition: opacity .15s; }
.home-link:hover { opacity: .75; }
.tagline { color: var(--muted); font-size: .85rem; margin-top: .2rem; }

.actions { display: flex; gap: .4rem; flex-wrap: wrap; align-items: center; }

button {
  font-family: inherit;
  font-size: .8rem;
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 5px;
  padding: .45rem .85rem;
  cursor: pointer;
  transition: background .15s;
}
button:hover { background: rgba(74, 222, 128, .08); }
button[data-toggle].active { background: var(--accent); color: #050507; }

.export-wrap { position: relative; }
.export-menu {
  position: absolute;
  right: 0;
  top: calc(100% + .3rem);
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 6px;
  display: flex;
  flex-direction: column;
  min-width: 120px;
  z-index: 10;
  overflow: hidden;
}
.export-menu button {
  border: none;
  border-radius: 0;
  text-align: left;
  padding: .55rem .85rem;
}
.export-menu button + button { border-top: 1px solid var(--border); }

.canvas-wrap {
  flex: 1;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  position: relative;
  min-height: 0;
}

#canvas {
  width: 100%;
  height: 100%;
  display: block;
  cursor: default;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
}
#canvas.connect-mode { cursor: crosshair; }

.node rect {
  fill: var(--node);
  stroke: var(--border);
  stroke-width: 1.5;
  rx: 6;
  transition: stroke .1s;
}
.node text {
  fill: var(--fg);
  font-family: ui-monospace, Menlo, monospace;
  font-size: 13px;
  pointer-events: none;
  dominant-baseline: middle;
  text-anchor: middle;
}
.node:hover rect { stroke: var(--accent); }
.node.selected rect { stroke: var(--accent); stroke-width: 2; }
.node.connect-src rect { stroke: var(--accent); stroke-dasharray: 4 3; }
.node { cursor: grab; }
.node.dragging { cursor: grabbing; }

.handle {
  fill: var(--panel);
  stroke: var(--accent);
  stroke-width: 1.5;
  opacity: 0;
  cursor: crosshair;
  transition: opacity .1s, r .1s;
}
.node:hover .handle,
.node.selected .handle,
.node.connect-src .handle,
#canvas.connecting .handle { opacity: 1; }
#canvas.connecting .node.drop-target rect { stroke: var(--accent); stroke-width: 2; }
#canvas.connecting .node.drop-target .handle { fill: var(--accent); }
.handle:hover { fill: var(--accent); }

.edge {
  fill: none;
  stroke: var(--accent);
  stroke-width: 1.6;
  opacity: .85;
}
.edge.selected { stroke-width: 2.5; opacity: 1; }
.edge-hit {
  fill: none;
  stroke: transparent;
  stroke-width: 14;
  cursor: pointer;
}

.hint {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  color: var(--dim);
  font-size: .85rem;
  pointer-events: none;
  text-align: center;
}
.hint b { color: var(--accent); font-weight: normal; }

footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: .1rem;
}
.status { color: var(--muted); font-size: .75rem; }
footer a { color: var(--muted); text-decoration: none; font-size: .85rem; }
footer a:hover { color: var(--accent); }

.toast {
  position: fixed;
  top: 1.25rem;
  left: 50%;
  transform: translateX(-50%);
  background: var(--panel);
  border: 1px solid var(--accent);
  color: var(--accent);
  padding: .55rem 1rem;
  border-radius: 6px;
  font-size: .8rem;
  z-index: 100;
  box-shadow: 0 8px 24px rgba(0, 0, 0, .5);
  animation: toast-in .2s ease-out;
}
@keyframes toast-in {
  from { opacity: 0; transform: translate(-50%, -8px); }
  to   { opacity: 1; transform: translate(-50%, 0); }
}

@media (max-width: 640px) {
  .actions { width: 100%; justify-content: flex-start; }
}