:root {
  --bg: #f2eee3; --panel: #faf8f1; --text: #1c1b19; --muted: #6a665c; --line: #cfc8b6;
  --accent: #d9480f; --blue: #1f3a93; --ok: #2d6a3e; --err: #b3261e; --warn: #b45309; --grid: rgba(31, 58, 147, .08);
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, "Book Antiqua", Georgia, serif;
  --mono: ui-monospace, "Cascadia Mono", Consolas, "Courier New", monospace;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #0f2236; --panel: #0b1b2d; --text: #e8efe9; --muted: #9db0c4; --line: #2c4660; --accent: #ff9b5e; --blue: #9ec1ff; --ok: #8bd6a0; --err: #ff8a7a; --warn: #ffb066; }
}
* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; }
body { display: flex; flex-direction: column; background: var(--bg); color: var(--text); font: 14px/1.4 system-ui, "Segoe UI", sans-serif; }
header { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 10px; padding: 8px 16px; background: var(--bg); border-bottom: 1px solid var(--text); }
h1 { margin: 0 10px 0 0; font: 600 20px/1.1 var(--serif); letter-spacing: -.01em; }
.brand { display: inline-flex; align-items: center; gap: 9px; color: inherit; text-decoration: none; }
.brand:hover { text-decoration: underline; text-underline-offset: 4px; text-decoration-thickness: 1px; }
.brand img { display: block; }
.badge { color: var(--muted); font: 11px var(--mono); text-transform: uppercase; letter-spacing: .06em; }
.spacer { flex: 1; }
label { color: var(--muted); display: flex; align-items: center; gap: 8px; font: 11px var(--mono); text-transform: uppercase; letter-spacing: .08em; }
select, button { font: 12px var(--mono); letter-spacing: .02em; color: var(--text); background: transparent; border: 1px solid var(--text); border-radius: 0; padding: 5px 10px; }
select { background: var(--panel); }
button { cursor: pointer; }
button:disabled { opacity: .35; cursor: default; }
button:disabled:hover { background: transparent; color: var(--text); }
button.primary { background: var(--text); color: var(--bg); }
button.primary:hover { background: transparent; color: var(--text); }
button.danger { border-color: var(--err); color: var(--err); }
button.danger:hover { background: var(--err); color: var(--bg); }
.dlg-actions { display: flex; gap: 8px; flex-wrap: wrap; margin: 4px 0 14px; }
button:hover { background: var(--text); color: var(--bg); }
main { flex: 1; min-height: 0; display: grid; grid-template-columns: minmax(0, var(--split, 50%)) 9px minmax(0, 1fr); }
.pane { position: relative; min-height: 0; min-width: 0; display: flex; flex-direction: column; }
.splitter { background: var(--bg); border-left: 1px solid var(--text); border-right: 1px solid var(--text); cursor: col-resize; touch-action: none; outline: 0; }
.splitter:hover, .splitter:focus-visible, body.dragging .splitter { background: var(--accent); }
body.dragging { user-select: none; cursor: col-resize; }
#editor { flex: 1; resize: none; border: 0; outline: 0; padding: 14px 16px; background: var(--panel); color: var(--text); font: 13px/1.6 ui-monospace, "Cascadia Mono", Consolas, monospace; tab-size: 2; }
#status { padding: 6px 16px; font: 11px var(--mono); color: var(--muted); border-top: 1px solid var(--line); background: var(--bg); min-height: 28px; white-space: pre-wrap; }
#status.error { color: var(--err); }
.legal-links { padding: 4px 16px; font: 11px var(--mono); color: var(--muted); border-top: 1px solid var(--line); background: var(--bg); }
.legal-links a { color: var(--muted); }
.preview { overflow: hidden; background-color: #fffefb; background-image: linear-gradient(var(--grid) 1px, transparent 1px), linear-gradient(90deg, var(--grid) 1px, transparent 1px); background-size: 24px 24px; }
#out { position: absolute; inset: 0; padding: 16px; display: flex; justify-content: center; align-items: flex-start; overflow: hidden; cursor: grab; touch-action: none; }
#out.panning { cursor: grabbing; }
#view { transform-origin: 0 0; max-width: 100%; }
#out svg { display: block; max-width: 100%; height: auto; }
.zoomctl { position: absolute; right: 12px; top: 12px; display: flex; gap: 0; }
.zoomctl button { min-width: 34px; background: #fffefb; color: #1c1b19; border-color: #1c1b19; }
.zoomctl button + button { border-left: 0; }
.zoomctl button:hover { background: #1c1b19; color: #fffefb; }

.feedback { font: 12px var(--mono); letter-spacing: .02em; color: var(--muted); text-decoration: underline; text-underline-offset: 3px; padding: 5px 4px; white-space: nowrap; }
.feedback:hover { color: var(--accent); }
.btn-pair { display: inline-flex; }
.btn-pair button + button { border-left: 0; }
button.icon { min-width: 34px; padding: 5px 8px; font-size: 15px; line-height: 1; }
.menu { position: relative; }
.menu > summary { list-style: none; cursor: pointer; font: 12px var(--mono); letter-spacing: .02em; border: 1px solid var(--text); padding: 5px 10px; user-select: none; }
.menu > summary::-webkit-details-marker { display: none; }
.menu > summary::after { content: " ▾"; }
.menu > summary:hover, .menu[open] > summary { background: var(--text); color: var(--bg); }
.menu-list { position: absolute; z-index: 20; top: 100%; left: 0; min-width: 100%; margin-top: 2px; display: flex; flex-direction: column; background: var(--bg); border: 1px solid var(--text); box-shadow: 4px 4px 0 var(--line); }
.menu-list button { border: 0; text-align: left; white-space: nowrap; padding: 7px 14px; }
.menu-right .menu-list { left: auto; right: 0; }
.menu-list button[aria-checked="true"]::before { content: "✓ "; }
.menu-list button[aria-checked="false"]::before { content: "\00a0\00a0 "; }
.preview.inverted { background-color: #14202e; background-image: linear-gradient(rgba(255,255,255,.07) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.07) 1px, transparent 1px); }
.preview.inverted #view { filter: invert(1) hue-rotate(180deg); }
.menu-list hr { margin: 2px 0; border: 0; border-top: 1px solid var(--line); }
.menu-list button.danger { border: 0; }
.linkbtn { font: inherit; font-size: 11px; padding: 0; border: 0; background: none; color: var(--muted); text-decoration: underline; cursor: pointer; }
.linkbtn:hover { color: var(--text); background: none; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

dialog { border: 1px solid var(--text); border-radius: 0; background: var(--bg); color: var(--text); padding: 0; width: min(780px, 94vw); max-height: 86vh; box-shadow: 8px 8px 0 var(--line); }
dialog::backdrop { background: rgba(15, 34, 54, .55); }
.dlg-body { padding: 18px 22px 22px; }
.dlg-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.dlg-head h2 { margin: 0; font: 600 24px/1.1 var(--serif); }
.dlg-sub { color: var(--muted); margin: 6px 0 14px; }
#tpl-list h3 { margin: 18px 0 8px; font: 11px var(--mono); text-transform: uppercase; letter-spacing: .1em; color: var(--accent); font-weight: 400; }
#tpl-list h4 { margin: 14px 0 6px; font: 11px var(--mono); letter-spacing: .06em; color: var(--muted); font-weight: 400; }
.tpl-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(210px, 1fr)); gap: 8px; }
.tpl { display: flex; flex-direction: column; align-items: flex-start; gap: 2px; text-align: left; padding: 10px 12px; font-family: system-ui, "Segoe UI", sans-serif; font-size: 14px; letter-spacing: 0; }
.tpl span { color: var(--muted); font-size: 12px; }
.tpl:hover span { color: inherit; }
.keys { border-collapse: collapse; width: 100%; margin-top: 10px; }
.keys td { padding: 7px 8px 7px 0; border-top: 1px solid var(--line); vertical-align: top; }
.keys td:first-child { white-space: nowrap; width: 1%; padding-right: 24px; }
kbd { font: 12px var(--mono); padding: 1px 6px; border: 1px solid var(--text); border-radius: 0; background: var(--panel); }
@media (max-width: 800px) {
  main { grid-template-columns: minmax(0, 1fr); grid-template-rows: minmax(0, var(--split, 50%)) 9px minmax(0, 1fr); }
  .splitter { cursor: row-resize; border: 0; border-top: 1px solid var(--text); border-bottom: 1px solid var(--text); }
  body.dragging { cursor: row-resize; }
}

@media print {
  @page { margin: 12mm; }
  html, body { height: auto; background: #fff; }
  header, .pane:not(.preview), .splitter, #status, #conv-note { display: none !important; }
  .zoomctl, dialog { display: none !important; }
  #out { position: static; overflow: visible; }
  #view { transform: none !important; }
  main { display: block; }
  .preview { overflow: visible; border: 0; background: #fff; }
  #out { padding: 0; }
  #out svg { max-width: 100%; max-height: 260mm; height: auto; }
  #out::after { content: "Made with Graph Manufacture"; display: block; text-align: right; margin-top: 4mm; font: 9pt system-ui, Arial, sans-serif; color: #8a93a3; }
}

#conv-note { padding: 8px 16px; font-size: 12px; border-top: 1px solid var(--line); background: var(--bg); }
.note-head { display: flex; gap: 12px; align-items: baseline; flex-wrap: wrap; }
.note-head > span { flex: 1 1 260px; }
.note-warn { color: var(--warn); }
.note-ok { color: var(--ok); }
#conv-note summary { cursor: pointer; margin-top: 6px; color: var(--muted); font: 11px var(--mono); }
.loss-list { margin: 0; padding: 0; list-style: none; max-height: 24vh; overflow: auto; border-left: 3px solid var(--accent); }
.loss-list li { display: grid; grid-template-columns: 64px minmax(0, 1fr); gap: 2px 10px; padding: 6px 10px; border-bottom: 1px dotted var(--line); font-size: 12px; }
.loss-line { color: var(--muted); grid-row: span 2; font: 11px var(--mono); }
.loss-list code { color: var(--text); overflow-wrap: anywhere; }
.loss-why { color: var(--muted); }
@media print { .preview.inverted { background: #fff; } .preview.inverted #view { filter: none; } }
body.editor-hidden main { grid-template-columns: minmax(0, 1fr); grid-template-rows: minmax(0, 1fr); }
body.editor-hidden main > .pane:not(.preview), body.editor-hidden #splitter { display: none; }
#view g.node, #view g.entity, #view g.dx-node { cursor: move; }
#view.dragging-node, #view.dragging-node * { cursor: grabbing !important; }
#view svg { overflow: visible; }

/* shapes panel (right) */
.palette { min-width: 0; background: var(--panel); padding: 12px; overflow: auto; }
.palette[hidden], .palette [hidden] { display: none; }
.palette h2 { margin: 0 0 8px; font: 400 11px var(--mono); text-transform: uppercase; letter-spacing: .1em; color: var(--muted); }
.pal-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; }
button.pal { display: flex; flex-direction: column; align-items: center; gap: 2px; padding: 6px 4px; font-size: 11px; cursor: grab; touch-action: none; }
button.pal svg { width: 40px; height: 28px; fill: none; stroke: currentColor; stroke-width: 1.5; }
button.pal svg path.plain { stroke-width: 2; }
.pal-hint { margin: 12px 0 0; font-size: 12px; line-height: 1.45; color: var(--muted); }
.palette p:has(#pal-switch) { margin: 12px 0 0; }
.pal-ghost { position: fixed; z-index: 50; pointer-events: none; opacity: .85; padding: 4px 10px; border: 1px dashed var(--accent); background: var(--panel); color: var(--text); font: 11px var(--mono); }
body.has-palette main { grid-template-columns: minmax(0, var(--split, 50%)) 9px minmax(0, 1fr) 9px var(--palw, 176px); }
body.editor-hidden.has-palette main { grid-template-columns: minmax(0, 1fr) 9px var(--palw, 176px); }
#view g.dx-sel { filter: drop-shadow(0 0 3px var(--accent)) drop-shadow(0 0 1px var(--accent)); }
.dx-resize { fill: #fff; stroke: var(--accent); stroke-width: 1.5; vector-effect: non-scaling-stroke; }
.dx-resize[data-h="nw"], .dx-resize[data-h="se"] { cursor: nwse-resize; }
.dx-resize[data-h="ne"], .dx-resize[data-h="sw"] { cursor: nesw-resize; }
.dx-resize[data-h="n"], .dx-resize[data-h="s"] { cursor: ns-resize; }
.dx-resize[data-h="e"], .dx-resize[data-h="w"] { cursor: ew-resize; }
.dx-handle { fill: var(--accent); stroke: #fff; stroke-width: 1.5; cursor: crosshair; }
.dx-rubber { stroke: var(--accent); stroke-width: 2; stroke-dasharray: 5 4; }
#view g.dx-editing text { visibility: hidden; }
.pal-ghost.shape { padding: 0; border: 0; background: none; opacity: .75; transform: translate(-50%, -50%); line-height: 0; }
.pal-ghost.shape svg { display: block; overflow: visible; }
.label-edit { position: fixed; z-index: 60; box-sizing: border-box; padding: 6px 8px; border: 1px dashed var(--accent); background: transparent; color: #111; font: 13px/1.3 system-ui, sans-serif; text-align: center; resize: none; }
@media (max-width: 800px) {
  .palette, #splitter2 { display: none !important; }
  body.has-palette main { grid-template-columns: minmax(0, 1fr); }
}
@media print { .palette, #splitter2 { display: none !important; } }

/* shape groups in the panel */
.pal-group { border-top: 1px solid var(--line); padding: 4px 0 6px; }
.pal-group > summary { cursor: pointer; list-style: none; padding: 5px 0; font: 11px var(--mono); text-transform: uppercase; letter-spacing: .06em; color: var(--text); }
.pal-group > summary::-webkit-details-marker { display: none; }
.pal-group > summary::before { content: "\25B8\00a0"; color: var(--muted); }
.pal-group[open] > summary::before { content: "\25BE\00a0"; }
.pal-group .pal-grid { margin: 4px 0 8px; }
button.pal svg { width: 100%; height: 30px; fill: none; stroke: none; }
button.pal[aria-pressed="true"] { background: var(--text); color: var(--bg); }
button.pal span { text-align: center; line-height: 1.15; overflow-wrap: anywhere; }
.dx-end { fill: #fff; stroke: var(--accent); stroke-width: 2; cursor: move; }
/* Tabs above the editor */
#tabs { display: flex; align-items: stretch; gap: 2px; overflow-x: auto; background: var(--bg); border-bottom: 1px solid var(--line); padding: 4px 8px 0; flex: none; }
#tabs .tab { display: flex; align-items: center; border: 1px solid var(--line); border-bottom: 0; border-radius: 6px 6px 0 0; background: var(--bg); color: var(--muted); white-space: nowrap; }
#tabs .tab.active { background: var(--panel); color: var(--text); border-color: var(--accent); }
#tabs .tab button, #tabs .tab-new { border: 0; background: transparent; color: inherit; font: 12px var(--mono); padding: 5px 8px; cursor: pointer; }
#tabs .tab-x { padding: 5px 6px; opacity: .6; }
#tabs .tab-x:hover, #tabs .tab-new:hover { opacity: 1; color: var(--accent); }
#tabs .tab-rename { font: 12px var(--mono); width: 130px; margin: 2px; background: var(--panel); color: var(--text); border: 1px solid var(--accent); }

/* Suggestions (Ctrl+Space) */
#ac { position: absolute; left: 16px; bottom: 44px; z-index: 20; margin: 0; padding: 4px 0; list-style: none; min-width: 200px; max-height: 220px; overflow: auto; background: var(--panel); color: var(--text); border: 1px solid var(--accent); border-radius: 6px; box-shadow: 0 6px 20px rgba(0, 0, 0, .25); font: 12px var(--mono); }
#ac[hidden] { display: none; }
#ac li { padding: 3px 12px; cursor: pointer; display: flex; justify-content: space-between; gap: 16px; }
#ac li.sel, #ac li:hover { background: var(--accent); color: #fff; }
#ac small { opacity: .75; font-size: 10px; }

/* Find in the diagram */
.findbar { position: absolute; left: 12px; top: 12px; z-index: 5; display: flex; align-items: center; gap: 0; background: #fffefb; border: 1px solid #1c1b19; }
.findbar input { width: 190px; border: 0; padding: 6px 8px; background: transparent; color: #1c1b19; font: 12px var(--mono); outline: 0; }
.findbar button { min-width: 28px; border: 0; border-left: 1px solid #1c1b19; background: #fffefb; color: #1c1b19; }
.findbar button:hover { background: #1c1b19; color: #fffefb; }
#find-count { font: 11px var(--mono); color: #6b6a65; padding: 0 6px; min-width: 20px; }
#view text.find-hit { paint-order: stroke; stroke: #fde047; stroke-width: 6px; stroke-linejoin: round; }
#view text.find-cur { stroke: #fb923c; stroke-width: 8px; }
.dlg-field { display: flex; flex-direction: column; gap: 4px; font: 12px var(--mono); margin: 8px 0; }
.dlg-field input { padding: 6px 8px; font: 13px var(--mono); background: var(--panel); color: var(--text); border: 1px solid var(--line); }
@media print { .findbar, #tabs, #ac { display: none !important; } }

/* Presentation mode: only the diagram, fullscreen */
.pres-exit { position: absolute; right: 12px; bottom: 12px; z-index: 6; opacity: .35; background: #fffefb; color: #1c1b19; border: 1px solid #1c1b19; font: 12px var(--mono); padding: 6px 10px; cursor: pointer; }
.pres-exit:hover, .pres-exit:focus-visible { opacity: 1; }
body.presenting header, body.presenting main > .pane:not(.preview), body.presenting .splitter, body.presenting #palette, body.presenting .findbar { display: none !important; }
body.presenting main { grid-template-columns: minmax(0, 1fr) !important; grid-template-rows: minmax(0, 1fr); }
#tabs .tab.dragging { position: relative; z-index: 3; opacity: .85; box-shadow: 0 3px 10px rgba(0, 0, 0, .35); cursor: grabbing; }
body:has(#tabs .tab.dragging) { user-select: none; }

/* Shapes panel: sections (UML, SysML, ...) holding folded groups, and the "Collapse all" button */
.pal-head { margin-bottom: 8px; display: flex; align-items: baseline; justify-content: space-between; gap: 8px; }
.pal-head h2 { margin: 0; }
.pal-section { border-top: 1px solid var(--line); padding: 4px 0 4px; }
.pal-section > summary { cursor: pointer; list-style: none; padding: 5px 0; font: 11px var(--mono); text-transform: uppercase; letter-spacing: .06em; color: var(--text); font-weight: 700; }
.pal-section > summary::-webkit-details-marker { display: none; }
.pal-section > summary::before { content: "\25B8\00a0"; color: var(--muted); }
.pal-section[open] > summary::before { content: "\25BE\00a0"; }
.pal-section > .pal-group { margin-left: 10px; }
.dx-wp { fill: var(--accent); stroke: #fff; stroke-width: 1.5; cursor: move; vector-effect: non-scaling-stroke; }
.dx-mid { fill: var(--accent); stroke: #fff; stroke-width: 1.5; opacity: .6; cursor: copy; vector-effect: non-scaling-stroke; }
.dx-mid:hover { opacity: 1; }

.arrow-tools { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; padding: 8px; margin-bottom: 8px; border: 1px solid var(--accent); border-radius: 6px; font-size: 12px; }
.arrow-tools[hidden] { display: none; }
.arrow-tools b { flex: 1 1 100%; }
.arrow-tools small { flex: 1 1 100%; color: var(--muted); }
.arrow-corners { display: inline-flex; gap: 4px; }
.arrow-tools button[aria-pressed="true"] { background: var(--accent); color: #fff; }

/* requirement table dialog */
#req-dialog { width: min(640px, 94vw); }
.req-rows { display: flex; flex-direction: column; gap: 6px; max-height: 50vh; overflow: auto; margin: 8px 0; }
.req-row { display: grid; grid-template-columns: 48px 1fr auto; gap: 6px; align-items: start; }
.req-row .req-id { font: 600 13px var(--mono); padding-top: 6px; }
.req-row textarea { resize: vertical; padding: 6px 8px; font: 13px/1.4 system-ui, sans-serif; background: var(--panel); color: var(--text); border: 1px solid var(--line); }
.req-x { padding: 4px 8px; }
#view g.req-table { cursor: pointer; }
.ai-choice { border: 1px solid var(--line); padding: 8px 12px; margin: 8px 0; display: flex; flex-direction: column; gap: 6px; }
.ai-choice label { display: flex; gap: 8px; align-items: center; }