:root {
  --bg: #f6f5f2;
  --panel: #ffffff;
  --ink: #1f2328;
  --muted: #6a6f76;
  --line: #dedbd4;
  --soft: #efece6;
  --accent: #2f5fd0;
  --accent-ink: #ffffff;
  --task: #2f6fd6;
  --event: #1b8a4a;
  --gw: #c47f00;
  --art: #7a6a92;
  --flow: #d0342c;
  --warn: #e07b00;
  --sel: #ff2d8a;
  --mono: Consolas, "Cascadia Mono", Menlo, "DejaVu Sans Mono", ui-monospace, monospace;
  --radius: 10px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #16181b; --panel: #1e2125; --ink: #e8e6e1; --muted: #9aa0a6; --line: #34383e; --soft: #262a2f;
    --accent: #6f95ff; --accent-ink: #0d1117; --task: #6f9dff; --event: #45c07a; --gw: #f0b43a; --art: #b39ddb;
    --flow: #ff6b61; --sel: #ff5ca8; color-scheme: dark;
  }
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
html, body { margin: 0; }
body {
  font: 15px/1.45 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg); color: var(--ink); min-height: 100vh; display: flex; flex-direction: column;
}
button, select, input, textarea { font: inherit; color: inherit; }
button {
  background: var(--panel); border: 1px solid var(--line); border-radius: 8px; padding: 6px 12px; cursor: pointer;
}
button:hover:not(:disabled) { border-color: var(--muted); }
button:disabled { opacity: .45; cursor: default; }
button.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); font-weight: 600; }
button.ghost { background: transparent; border-color: transparent; }
button.ghost:hover:not(:disabled) { background: var(--soft); }
button:focus-visible, .drop:focus-visible, pre:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* header */
.top { display: flex; align-items: center; justify-content: space-between; padding: 12px 20px; border-bottom: 1px solid var(--line); background: var(--panel); }
.brand { display: flex; gap: 10px; align-items: center; }
.brand h1 { font-size: 18px; margin: 0; letter-spacing: .2px; }
.brand .tag { margin: 0; color: var(--muted); font-size: 13px; }
.top-actions { display: flex; gap: 8px; align-items: center; }
.badge { font-size: 12px; padding: 3px 8px; border-radius: 99px; background: var(--soft); color: var(--muted); }

/* drop */
.drop-view { flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 18px; padding: 32px 16px; }
.drop {
  width: min(720px, 100%); min-height: 280px; border: 2px dashed var(--line); border-radius: 18px; background: var(--panel);
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 8px; padding: 32px; text-align: center; cursor: pointer;
  transition: border-color .15s, background .15s;
}
.drop:hover, .drop.over { border-color: var(--accent); background: color-mix(in srgb, var(--accent) 6%, var(--panel)); }
.drop svg { fill: none; stroke: var(--muted); stroke-width: 2; margin-bottom: 6px; }
.drop strong { font-size: 18px; }
.drop span { color: var(--muted); }
.drop small { color: var(--muted); max-width: 460px; margin-top: 8px; }
.samples { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; justify-content: center; color: var(--muted); }

/* busy */
.busy-view { flex: 1; display: flex; align-items: center; justify-content: center; padding: 24px; }
.busy { width: min(420px, 100%); text-align: center; }
.busy small { color: var(--muted); }
.spinner { width: 34px; height: 34px; margin: 0 auto 12px; border-radius: 50%; border: 3px solid var(--line); border-top-color: var(--accent); animation: spin 0.9s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.bar { height: 6px; background: var(--soft); border-radius: 99px; overflow: hidden; margin: 10px 0 14px; }
.bar div { height: 100%; width: 0; background: var(--accent); transition: width .2s; }

/* workspace */
.work-view {
  flex: 1; display: grid; gap: 14px; padding: 14px;
  grid-template-columns: minmax(0, 1fr) 320px;
  grid-template-rows: minmax(360px, 58vh) auto;
  grid-template-areas: "editor inspector" "output output";
}
.editor { grid-area: editor; display: flex; flex-direction: column; min-width: 0; background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.inspector { grid-area: inspector; background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 14px; overflow: auto; }
.output { grid-area: output; background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); min-width: 0; display: flex; flex-direction: column; }

.toolbar { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; padding: 8px 10px; border-bottom: 1px solid var(--line); }
.toolbar .grow { flex: 1; }
.muted { color: var(--muted); font-size: 13px; }
.seg { display: inline-flex; border: 1px solid var(--line); border-radius: 8px; overflow: hidden; }
.seg button { border: 0; border-radius: 0; background: transparent; padding: 6px 11px; }
.seg button + button { border-left: 1px solid var(--line); }
.seg button.on { background: var(--ink); color: var(--panel); }
.seg.small button { padding: 4px 9px; font-size: 13px; }
.check { display: inline-flex; gap: 5px; align-items: center; font-size: 13px; color: var(--muted); }

.stage-wrap { flex: 1; overflow: auto; background:
  repeating-conic-gradient(var(--soft) 0 25%, transparent 0 50%) 0 0 / 16px 16px; position: relative; }
.stage { position: relative; margin: 0 auto; transform-origin: 0 0; }
.stage img { display: block; width: 100%; height: 100%; user-select: none; -webkit-user-drag: none; background: #fff; }
.stage.no-img img { opacity: 0.08; }
.overlay { position: absolute; inset: 0; width: 100%; height: 100%; }
.overlay .node { fill: transparent; stroke-width: 2.5; vector-effect: non-scaling-stroke; cursor: pointer; }
.overlay .node:hover { fill: color-mix(in srgb, currentColor 12%, transparent); }
.overlay .node.task { color: var(--task); stroke: var(--task); }
.overlay .node.event { color: var(--event); stroke: var(--event); }
.overlay .node.gw { color: var(--gw); stroke: var(--gw); }
.overlay .node.art { color: var(--art); stroke: var(--art); }
.overlay .flow { fill: none; stroke: var(--flow); stroke-width: 2.5; vector-effect: non-scaling-stroke; pointer-events: none; }
.overlay .flow.message { stroke-dasharray: 7 5; }
.overlay .flow.association { stroke-dasharray: 2 4; }
.overlay .hit { fill: none; stroke: transparent; stroke-width: 14; vector-effect: non-scaling-stroke; cursor: pointer; pointer-events: stroke; }
.overlay .hit:hover + .flow, .overlay g.sel .flow { stroke-width: 4; }
.overlay g.sel .node, .overlay .node.sel { stroke: var(--sel); fill: color-mix(in srgb, var(--sel) 12%, transparent); }
.overlay g.sel .flow { stroke: var(--sel); }
.overlay .lane { fill: transparent; stroke: var(--muted); stroke-dasharray: 4 4; stroke-width: 1; vector-effect: non-scaling-stroke; pointer-events: none; }
.overlay .lanetag { cursor: pointer; }
.overlay .lanetag rect { fill: var(--panel); stroke: var(--line); vector-effect: non-scaling-stroke; }
.overlay .lanetag.sel rect { stroke: var(--sel); }
.overlay .lanetag text { fill: var(--ink); font: 600 12px system-ui, sans-serif; }
.overlay .warn { fill: var(--warn); stroke: var(--panel); stroke-width: 2; vector-effect: non-scaling-stroke; pointer-events: none; }
.overlay .draft { fill: color-mix(in srgb, var(--accent) 12%, transparent); stroke: var(--accent); stroke-dasharray: 5 4; vector-effect: non-scaling-stroke; }
.overlay .pending { stroke: var(--sel); stroke-width: 3; }
.stage.mode-box, .stage.mode-box .node, .stage.mode-box .hit { cursor: crosshair; }
.stage.mode-connect .node { cursor: alias; }
.hint { margin: 0; padding: 8px 12px; border-top: 1px solid var(--line); font-size: 13px; color: var(--muted); }
.k { display: inline-block; width: 10px; height: 10px; border-radius: 3px; margin: 0 4px 0 10px; vertical-align: -1px; border: 2px solid; }
.k.task { border-color: var(--task); } .k.event { border-color: var(--event); border-radius: 50%; }
.k.gw { border-color: var(--gw); transform: rotate(45deg) scale(.85); } .k.art { border-color: var(--art); } .k.flow { border-color: var(--flow); height: 0; border-width: 2px 0 0; width: 14px; }

/* inspector */
.inspector h2 { font-size: 15px; margin: 0 0 10px; }
.inspector h3 { font-size: 13px; margin: 18px 0 6px; color: var(--muted); text-transform: uppercase; letter-spacing: .5px; }
.inspector label { display: block; font-size: 13px; color: var(--muted); margin: 10px 0 4px; }
.inspector select, .inspector input, .inspector textarea { width: 100%; padding: 7px 9px; border: 1px solid var(--line); border-radius: 8px; background: var(--bg); }
.inspector textarea { min-height: 70px; resize: vertical; }
.inspector .row { display: flex; gap: 8px; margin-top: 14px; flex-wrap: wrap; }
.inspector .stats { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.inspector .stat { background: var(--soft); border-radius: 8px; padding: 8px 10px; }
.inspector .stat b { display: block; font-size: 20px; }
.inspector .stat span { font-size: 12px; color: var(--muted); }
.inspector ul.warns { list-style: none; padding: 0; margin: 0; }
.inspector ul.warns li { padding: 7px 9px; border-radius: 8px; margin-bottom: 6px; background: color-mix(in srgb, var(--warn) 12%, transparent); cursor: pointer; font-size: 13px; }
.inspector ul.warns li:hover { background: color-mix(in srgb, var(--warn) 22%, transparent); }
.inspector .endpoints { font-size: 13px; background: var(--soft); border-radius: 8px; padding: 8px 10px; }
.inspector .tip { font-size: 13px; color: var(--muted); }
.inspector kbd { font: 12px var(--mono); border: 1px solid var(--line); border-bottom-width: 2px; border-radius: 4px; padding: 0 4px; }
button.danger { color: #c62828; }

/* output */
.preview {
  margin: 0; padding: 14px 16px; overflow: auto; font: 13px/1.12 var(--mono); max-height: 60vh; min-height: 120px;
  white-space: pre; tab-size: 4; font-variant-ligatures: none;
}
details.more { position: relative; }
details.more summary { list-style: none; cursor: pointer; border: 1px solid var(--line); border-radius: 8px; padding: 6px 12px; }
details.more summary::-webkit-details-marker { display: none; }
details.more > div { position: absolute; right: 0; top: 110%; z-index: 5; background: var(--panel); border: 1px solid var(--line); border-radius: 10px; padding: 6px; display: flex; flex-direction: column; gap: 4px; min-width: 170px; box-shadow: 0 8px 24px rgb(0 0 0 / .12); }
details.more > div button { text-align: left; border: 0; }

/* dialog, toast */
dialog { border: 1px solid var(--line); border-radius: 14px; background: var(--panel); color: var(--ink); max-width: 640px; width: calc(100% - 32px); padding: 22px 24px; }
dialog::backdrop { background: rgb(0 0 0 / .4); }
dialog h2 { margin-top: 0; } dialog h3 { margin-bottom: 4px; font-size: 15px; }
dialog li { margin-bottom: 6px; }
dialog .legend { font: 12.5px/1.35 var(--mono); background: var(--soft); padding: 10px 12px; border-radius: 8px; overflow: auto; }
.toast { position: fixed; bottom: 20px; left: 50%; transform: translateX(-50%); background: var(--ink); color: var(--panel); padding: 9px 16px; border-radius: 99px; font-size: 14px; z-index: 20; }

@media (max-width: 900px) {
  .work-view { grid-template-columns: 1fr; grid-template-rows: minmax(300px, 50vh) auto auto; grid-template-areas: "editor" "inspector" "output"; padding: 10px; }
  .top { padding: 10px 14px; }
  .brand .tag { display: none; }
}