:root {
  color-scheme: dark;
  --page: #0d0d0d;
  --surface: #1a1a19;
  --surface-2: #232322;
  --ink: #ffffff;
  --ink-2: #c3c2b7;
  --muted: #898781;
  --hairline: #2c2c2a;
  --border: rgba(255,255,255,0.10);
  --side-a: #3987e5;   /* blue = side A */
  --side-b: #e66767;   /* red  = side B */
  --add: #0ca30c;
  --del: #d03b3b;
}
* { box-sizing: border-box; }
body {
  margin: 0; padding: 16px 20px; background: var(--page); color: var(--ink);
  font: 13px/1.45 system-ui, -apple-system, "Segoe UI", sans-serif;
}
header { display: flex; align-items: baseline; gap: 12px; margin-bottom: 14px; }
h1 { font-size: 16px; margin: 0; font-weight: 650; }
h2 { font-size: 13px; font-weight: 600; margin: 0 0 8px; }
h3 { font-size: 12px; font-weight: 600; margin: 0 0 6px; color: var(--ink-2); }
.muted { color: var(--muted); font-size: 12px; }
.hidden { display: none !important; }

/* combined text/token inputs */
#inputs { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 12px; }
.input-head { display: flex; align-items: baseline; justify-content: space-between; margin-bottom: 4px; }
.input-head label { font-size: 12px; color: var(--ink-2); }
.edit-btn { padding: 0 6px; border: 0; background: none; color: var(--muted); font-size: 11px; }
.edit-btn:hover { background: none; color: var(--ink); }
.tok-input { background: var(--surface); border: 1px solid var(--border); border-radius: 6px; }
.tok-input:focus-within { outline: 1px solid var(--side-a); }
textarea {
  display: block; width: 100%; height: 110px; resize: vertical; padding: 8px;
  background: transparent; color: var(--ink); border: 0; border-radius: 6px;
  font: 12px/1.5 ui-monospace, Menlo, monospace;
}
textarea:focus { outline: none; }
.tok-view { margin: 0; padding: 7px 8px; min-height: 110px; max-height: 220px; overflow-y: auto; align-content: start; }
.tok-view:not(.selectable) { cursor: text; }
.row { display: flex; align-items: center; gap: 10px; margin-top: 6px; }
.check { display: flex; align-items: center; gap: 5px; font-size: 12px; color: var(--ink-2); }
button {
  background: var(--surface-2); color: var(--ink); border: 1px solid var(--border);
  border-radius: 6px; padding: 5px 14px; font: inherit; cursor: pointer;
}
button:hover { background: #2e2e2c; }
#analyze { background: var(--side-a); border-color: transparent; font-weight: 600; }
#analyze:hover { background: #2a78d6; }
#analyze:disabled { opacity: 0.5; cursor: wait; }
select {
  background: var(--surface-2); color: var(--ink); border: 1px solid var(--border);
  border-radius: 6px; padding: 4px 6px; font: inherit;
}

.side-dot { display: inline-block; width: 8px; height: 8px; border-radius: 50%; }
.side-dot.a { background: var(--side-a); }
.side-dot.b { background: var(--side-b); }

/* token strips */
.token-strip { display: flex; flex-wrap: wrap; gap: 2px; }
.tok {
  padding: 1px 3px; border-radius: 3px; background: var(--surface-2); border: 1px solid transparent;
  font: 11px/1.4 ui-monospace, Menlo, monospace; white-space: pre; color: var(--ink-2);
}
.tok.changed-a { border-bottom: 2px solid var(--del); color: var(--ink); }
.tok.changed-b { border-bottom: 2px solid var(--add); color: var(--ink); }
.selectable .tok { cursor: pointer; user-select: none; }
.selectable .tok.selected { background: #24344a; border-color: var(--side-a); color: var(--ink); }
.selectable .tok.hovered { outline: 1px solid var(--ink-2); }
.hint { margin-top: 4px; }

#controls { display: flex; align-items: center; gap: 14px; margin: 16px 0 8px; }
.seg { display: inline-flex; border: 1px solid var(--border); border-radius: 6px; overflow: hidden; }
.seg button { border: 0; border-radius: 0; padding: 4px 16px; background: var(--surface); }
.seg button.active { background: var(--surface-2); color: var(--ink); font-weight: 650; box-shadow: inset 0 -2px 0 var(--side-a); }
#concept-banner { display: flex; align-items: center; flex-wrap: wrap; gap: 6px; background: var(--surface-2); border: 1px solid var(--border); border-radius: 6px; padding: 3px 8px; }
#concept-banner button { padding: 0 6px; border: 0; background: none; color: var(--muted); }
#concept-tokens { display: inline-flex; flex-wrap: wrap; gap: 4px; }
.tok-chip.removable { cursor: pointer; }
.tok-chip.removable:hover { border-color: var(--side-b); text-decoration: line-through; }
#legend { display: flex; align-items: center; gap: 6px; margin-left: auto; }
#legend canvas { border-radius: 3px; border: 1px solid var(--border); }

#heatmap-wrap { position: relative; overflow-x: auto; padding-bottom: 4px; }
#heatmap { display: block; }

#tooltip {
  position: fixed; z-index: 10; max-width: 340px; padding: 8px 10px;
  background: var(--surface-2); border: 1px solid var(--border); border-radius: 6px;
  box-shadow: 0 4px 16px rgba(0,0,0,0.5); font-size: 12px; pointer-events: none;
}
#tooltip.pinned { pointer-events: auto; }
#tooltip .tt-head { color: var(--muted); margin-bottom: 4px; }
#tooltip table { border-collapse: collapse; }
#tooltip td { padding: 0 6px 1px 0; font-family: ui-monospace, Menlo, monospace; font-size: 11px; }
#tooltip td.num { text-align: right; color: var(--ink-2); }
.tok-chip {
  font-family: ui-monospace, Menlo, monospace; background: var(--surface); border: 1px solid var(--border);
  border-radius: 3px; padding: 0 4px; white-space: pre;
}
#tooltip.pinned .tok-chip { cursor: pointer; }
#tooltip.pinned .tok-chip:hover { border-color: var(--side-a); }
.d-a { color: var(--side-a); } .d-b { color: var(--side-b); }

/* top-moving concepts */
#movers { margin-top: 14px; }
.movers-cols { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; }
.movers-list { max-height: 320px; overflow-y: auto; padding-right: 6px; }
.mover-row {
  display: grid; grid-template-columns: minmax(60px, 160px) 1fr 48px;
  align-items: center; gap: 8px; padding: 1px 4px; cursor: pointer; border-radius: 4px;
}
.mover-row:hover { background: var(--surface-2); }
.mover-row.pinned { background: #24344a; outline: 1px solid var(--side-a); }
.mover-row .tok-chip { overflow: hidden; text-overflow: ellipsis; justify-self: start; max-width: 100%; }
.mover-row .bar { height: 8px; border-radius: 2px 4px 4px 2px; }
.mover-row .bar.a { background: var(--side-a); }
.mover-row .bar.b { background: var(--side-b); }
.mover-row .score { font: 11px ui-monospace, Menlo, monospace; color: var(--muted); text-align: right; }