:root {
  --bg: #f4f5f7;
  --card: #ffffff;
  --text: #1d2024;
  --muted: #646b75;
  --border: #dde0e5;
  --accent: #2f6fed;
  --accent-text: #ffffff;
  --drop: #eef3fe;
  --canvas: #ffffff;
  --error: #c62828;
  --ok: #2e7d32;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15171a;
    --card: #1e2125;
    --text: #e6e8eb;
    --muted: #9aa1ab;
    --border: #33373d;
    --accent: #5b8ef5;
    --drop: #1c2533;
    --error: #ef5350;
    --ok: #66bb6a;
  }
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
body {
  margin: 0;
  font: 14px/1.45 system-ui, -apple-system, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
}
header {
  display: flex; align-items: baseline; gap: 12px;
  padding: 14px 20px; border-bottom: 1px solid var(--border); background: var(--card);
}
h1 { margin: 0; font-size: 20px; }
h2 { margin: 0 0 10px; font-size: 14px; text-transform: uppercase; letter-spacing: .04em; color: var(--muted); }
.sub { color: var(--muted); }

main {
  display: grid;
  grid-template-columns: 340px minmax(0, 1fr);
  gap: 16px;
  padding: 16px 20px;
  align-items: start;
}
@media (max-width: 900px) { main { grid-template-columns: 1fr; } }

aside { display: flex; flex-direction: column; gap: 12px; max-height: calc(100vh - 90px); overflow: auto; position: sticky; top: 16px; }
@media (max-width: 900px) { aside { position: static; max-height: none; } }

.card { background: var(--card); border: 1px solid var(--border); border-radius: 10px; padding: 14px; }
.row { display: flex; flex-direction: column; gap: 3px; margin-bottom: 9px; }
.row label { font-weight: 600; font-size: 13px; }
.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
input[type=number], input[type=text], textarea, select {
  font: inherit; color: inherit; background: var(--bg);
  border: 1px solid var(--border); border-radius: 6px; padding: 6px 8px; width: 100%;
}
textarea { font-family: ui-monospace, Consolas, monospace; min-height: 54px; resize: vertical; }
input[type=text] { font-family: ui-monospace, Consolas, monospace; }
.check { display: flex; align-items: center; gap: 6px; margin: 4px 0; cursor: pointer; }
.mode-option { align-items: flex-start; padding: 4px 0; }
.mode-option input { margin-top: 3px; }
.hint { color: var(--muted); font-size: 12px; margin: 4px 0 0; }
.desc { color: var(--muted); font-size: 12px; }

details { border-top: 1px solid var(--border); padding: 6px 0; }
details summary { cursor: pointer; font-weight: 600; padding: 4px 0; }
details .row, details .check { margin-left: 4px; }

button, .button {
  font: inherit; font-weight: 600; cursor: pointer; text-decoration: none; display: inline-block;
  background: var(--accent); color: var(--accent-text); border: 1px solid var(--accent);
  border-radius: 7px; padding: 8px 14px;
}
button.secondary, .button.secondary { background: transparent; color: var(--accent); }
button.small { padding: 3px 9px; font-size: 12px; }
button:disabled { opacity: .45; cursor: default; }
#resetBtn { margin-top: 10px; width: 100%; }

#work { display: flex; flex-direction: column; gap: 12px; min-width: 0; }

#drop {
  display: flex; align-items: center; justify-content: center; gap: 16px;
  min-height: 140px; padding: 14px;
  border: 2px dashed var(--accent); border-radius: 12px; background: var(--drop);
  cursor: pointer; text-align: center; transition: background .15s;
}
#drop.has-image { min-height: 0; justify-content: flex-start; text-align: left; }
#drop.dragover { background: color-mix(in srgb, var(--accent) 18%, var(--drop)); }
#dropText { display: flex; flex-direction: column; gap: 2px; }
#dropText span { color: var(--muted); }
#thumb { max-height: 90px; max-width: 160px; border-radius: 6px; }

.actions { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
#status { color: var(--muted); }
#status.error { color: var(--error); }
#status.ok { color: var(--ok); }

.preview-card { padding: 10px; }
.preview-toolbar { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; margin-bottom: 8px; }
.small { font-size: 12px; }
#lineWidthMm { display: inline-block; min-width: 52px; font-variant-numeric: tabular-nums; font-weight: 600; }
.legend { display: inline-block; width: 9px; height: 9px; border-radius: 50%; margin: 0 3px 0 6px; vertical-align: middle; }
.legend.start { background: #22c55e; }
.legend.end { background: #ef4444; }

#canvasWrap { position: relative; height: 62vh; min-height: 320px; border: 1px solid var(--border); border-radius: 8px; overflow: hidden; background: #fff; }
#canvas { width: 100%; height: 100%; display: block; cursor: grab; touch-action: none; }
#canvas.dragging { cursor: grabbing; }
#emptyPreview { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; color: #8a9099; pointer-events: none; }

#stats { display: grid; grid-template-columns: repeat(auto-fill, minmax(170px, 1fr)); gap: 8px 16px; margin: 0 0 12px; }
#stats div { display: flex; flex-direction: column; }
#stats dt { color: var(--muted); font-size: 12px; }
#stats dd { margin: 0; font-weight: 600; font-variant-numeric: tabular-nums; }
.downloads { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
.downloads select { width: auto; }
pre { margin: 0; max-height: 300px; overflow: auto; font-size: 12px; background: var(--bg); padding: 10px; border-radius: 6px; }