/* Section 6: the circuit, simulated live in the browser. Always dark, like an instrument. */

/* The navigation has one more link now: keep every link on one line. */
.nav-links a { white-space: nowrap; }
@media (max-width: 1180px) { .nav-links a { padding: 7px 8px; font-size: 13.5px; } }
@media (max-width: 1060px) { .nav-links { display: none; } .nav .icon-btn { margin-left: auto; } }
/* Grid items with code blocks or long links must not push the page sideways on phones. */
.grid > * { min-width: 0; }
td a { overflow-wrap: anywhere; }
.lab {
  --lab-bg: #06111f;
  --lab-panel: #0b1b30;
  --lab-panel-2: #102540;
  --lab-line: rgba(158, 197, 244, 0.16);
  --lab-ink: #eef3fa;
  --lab-ink-2: #a9bbd3;
  --lab-muted: #7489a6;
  --lab-accent: #86b6ef;
  --lab-blue: #2a78d6;
  --lab-best: #f2b33d;
  background:
    radial-gradient(900px 520px at 85% 0%, rgba(42, 120, 214, 0.22), transparent 65%),
    radial-gradient(700px 480px at 0% 100%, rgba(42, 120, 214, 0.12), transparent 60%),
    var(--lab-bg);
  color: var(--lab-ink);
  border-block: 1px solid #0c2140;
}
.lab .eyebrow { color: var(--lab-accent); }
.lab .eyebrow b { background: rgba(134, 182, 239, 0.14); }
.lab h2 { color: var(--lab-ink); }
.lab .lead { color: var(--lab-ink-2); }

.lab-shell { margin-top: 34px; display: grid; gap: 18px; }
.lab-panel {
  background: linear-gradient(180deg, var(--lab-panel-2), var(--lab-panel));
  border: 1px solid var(--lab-line); border-radius: 16px; padding: 20px;
}
.lab-panel h3 { font-size: 17px; color: var(--lab-ink); margin-bottom: 4px; }
.lab-sub { font-size: 13.5px; color: var(--lab-ink-2); margin-bottom: 12px; }

/* toolbar */
.lab-toolbar { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }
.seg { display: inline-flex; align-items: center; gap: 2px; padding: 3px; border-radius: 11px; border: 1px solid var(--lab-line); background: rgba(255, 255, 255, 0.03); }
.seg-label { font-size: 13px; color: var(--lab-ink-2); padding: 0 8px 0 9px; }
.seg button {
  font: inherit; font-size: 14px; font-weight: 700; color: var(--lab-ink-2); background: none; border: 0;
  width: 36px; height: 32px; border-radius: 8px; cursor: pointer; transition: background 0.2s, color 0.2s;
}
.seg button:hover { color: var(--lab-ink); background: rgba(255, 255, 255, 0.06); }
.seg button[aria-checked="true"] { background: var(--lab-blue); color: #fff; }
.lab-btn {
  display: inline-flex; align-items: center; gap: 8px; font: inherit; font-size: 14px; font-weight: 600;
  color: var(--lab-ink); background: rgba(255, 255, 255, 0.04); border: 1px solid var(--lab-line);
  padding: 9px 14px; border-radius: 10px; cursor: pointer; transition: background 0.2s, border-color 0.2s, transform 0.15s;
}
.lab-btn svg { width: 14px; height: 14px; }
.lab-btn:hover { border-color: rgba(158, 197, 244, 0.45); background: rgba(255, 255, 255, 0.08); }
.lab-btn:active { transform: translateY(1px); }
.lab-btn.primary { background: var(--lab-blue); border-color: var(--lab-blue); color: #fff; }
.lab-btn.primary:hover { background: #3987e5; border-color: #3987e5; }
.lab-btn.quiet { background: none; border-color: transparent; color: var(--lab-ink-2); }
.lab-btn.quiet:hover { color: var(--lab-ink); border-color: var(--lab-line); }
.lab-btn[disabled] { opacity: 0.5; cursor: default; }
.lab-btn:focus-visible, .seg button:focus-visible, .stage:focus-visible, .lab input[type="range"]:focus-visible, #lab-land:focus-visible {
  outline: 2px solid var(--lab-accent); outline-offset: 2px;
}

/* main row */
.lab-main { display: grid; grid-template-columns: minmax(0, 1fr) 330px; gap: 18px; }
.lab-amp { padding: 16px 18px 14px; }
.lab-canvas-wrap { position: relative; height: 300px; }
.lab-canvas-wrap canvas, .land-wrap canvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
.lab-axis { display: flex; justify-content: space-between; gap: 12px; font-size: 12px; color: var(--lab-muted); margin-top: 6px; }
.phase-key { display: inline-flex; align-items: center; gap: 8px; }
.phase-key i { width: 54px; height: 8px; border-radius: 4px; display: inline-block;
  background: linear-gradient(90deg, hsl(210 85% 62%), hsl(270 75% 66%), hsl(330 75% 64%), hsl(30 85% 60%), hsl(90 60% 55%), hsl(150 60% 52%), hsl(210 85% 62%)); }
.lab-caption { font-size: 14.5px; color: var(--lab-ink); margin: 10px 0 0; min-height: 2.9em; }

/* circuit steps */
.lab-stages { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 12px; }
.stage {
  position: relative; font: inherit; font-size: 12.5px; font-weight: 600; color: var(--lab-ink-2);
  background: rgba(255, 255, 255, 0.03); border: 1px solid var(--lab-line); border-radius: 999px;
  padding: 5px 11px; cursor: pointer; overflow: hidden; transition: color 0.2s, border-color 0.2s;
}
.stage .fill { position: absolute; inset: 0; width: 0; background: rgba(42, 120, 214, 0.35); z-index: 0; }
.stage span { position: relative; z-index: 1; }
.stage.cost { --stage: #c98bf0; }
.stage.mix { --stage: #86b6ef; }
.stage.done { color: var(--lab-ink); border-color: rgba(158, 197, 244, 0.4); }
.stage.done .fill { width: 100%; }
.stage.now { color: #fff; border-color: var(--lab-accent); }
.stage.cost .fill { background: rgba(176, 110, 230, 0.32); }

/* readouts */
.lab-read { display: flex; flex-direction: column; }
.read-big span { display: block; font-size: 52px; font-weight: 800; letter-spacing: -0.035em; line-height: 1; color: var(--lab-ink); }
.read-big small { display: block; font-size: 13.5px; color: var(--lab-ink-2); margin-top: 8px; }
.read-vs { margin-top: 12px; font-size: 14px; font-weight: 700; color: var(--lab-best); min-height: 1.4em; }
.read-meter { height: 6px; border-radius: 99px; background: rgba(255, 255, 255, 0.07); overflow: hidden; margin: 14px 0 4px; }
.read-meter i { display: block; height: 100%; width: 0; background: linear-gradient(90deg, var(--lab-blue), var(--lab-best)); border-radius: 99px; transition: width 0.25s; }
.read-kv { display: grid; grid-template-columns: 1fr auto; gap: 8px 12px; font-size: 13.5px; margin: 14px 0 0; }
.read-kv dt { color: var(--lab-ink-2); }
.read-kv dd { margin: 0; font-weight: 700; text-align: right; color: var(--lab-ink); white-space: nowrap; }
.read-check { margin: auto 0 0; padding-top: 16px; font-size: 12.5px; color: var(--lab-ink-2); border-top: 1px solid var(--lab-line); }
.read-check b { color: #7fd6a8; }

/* lower row */
.lab-lower { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr); gap: 18px; }
.land-wrap { position: relative; height: 250px; margin-left: 22px; margin-bottom: 22px; }
#lab-land { cursor: crosshair; border-radius: 8px; touch-action: none; }
.land-y, .land-x { position: absolute; font-size: 13px; color: var(--lab-ink-2); font-style: italic; }
.land-y { left: -22px; top: 50%; transform: translateY(-50%); }
.land-x { bottom: -22px; left: 50%; transform: translateX(-50%); }
.sliders { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px 18px; margin-top: 6px; }
.slider { display: grid; grid-template-columns: 30px minmax(0, 1fr) 46px; gap: 8px; align-items: center; font-size: 13px; color: var(--lab-ink-2); }
.slider output { font-variant-numeric: tabular-nums; color: var(--lab-ink); text-align: right; font-weight: 600; }
.lab input[type="range"] { width: 100%; accent-color: var(--lab-blue); }

.shot-btns { display: flex; flex-wrap: wrap; gap: 10px; }
.bits { display: grid; grid-template-columns: repeat(10, minmax(0, 1fr)); gap: 5px; margin: 18px 0 10px; }
.bit {
  aspect-ratio: 1 / 1.25; border-radius: 8px; border: 1px solid var(--lab-line); background: rgba(255, 255, 255, 0.03);
  display: grid; place-items: center; font-weight: 800; font-size: 17px; color: var(--lab-muted);
  font-variant-numeric: tabular-nums; position: relative;
}
.bit small { position: absolute; bottom: 3px; font-size: 9px; font-weight: 600; color: var(--lab-muted); }
.bit.on { background: var(--lab-blue); border-color: var(--lab-accent); color: #fff; }
.bit.on small { color: #d8e7fb; }
.bit.flash { animation: bitflash 0.5s ease; }
@keyframes bitflash { 0% { transform: scale(0.82); opacity: 0.3; } 100% { transform: none; opacity: 1; } }
.shot-plan { font-size: 14px; color: var(--lab-ink); min-height: 2.8em; }
.shot-plan .best { color: var(--lab-best); font-weight: 700; }
.shot-tally { display: grid; gap: 6px; margin-top: 12px; }
.tally-row { display: grid; grid-template-columns: minmax(0, 1fr) 120px 34px; gap: 10px; align-items: center; font-size: 12.5px; color: var(--lab-ink-2); }
.tally-row .tl { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.tally-row .tb { height: 8px; border-radius: 4px; background: rgba(255, 255, 255, 0.06); overflow: hidden; }
.tally-row .tb i { display: block; height: 100%; background: var(--lab-blue); border-radius: 4px; transition: width 0.3s; }
.tally-row.best .tb i { background: var(--lab-best); }
.tally-row.best .tl { color: var(--lab-best); }
.tally-row .tc { text-align: right; font-variant-numeric: tabular-nums; color: var(--lab-ink); font-weight: 600; }

@media (max-width: 980px) {
  .lab-main, .lab-lower { grid-template-columns: 1fr; }
  .lab-canvas-wrap { height: 240px; }
}
@media (max-width: 560px) {
  .sliders { grid-template-columns: 1fr; }
  .lab-toolbar .lab-btn { flex: 1 1 auto; justify-content: center; }
  .bits { gap: 3px; }
  /* Narrow boxes: make them taller and keep the digit above the qubit label, so the two never touch. */
  .bit { font-size: 14px; aspect-ratio: 1 / 1.7; padding-bottom: 12px; }
  .bit small { font-size: 8px; bottom: 2px; }
}
@media (prefers-reduced-motion: reduce) {
  .bit.flash { animation: none; }
  .read-meter i, .tally-row .tb i { transition: none; }
}

/* plan today's visit */
.lab-plan { display: grid; grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr); gap: 22px; }
#plan-svg svg { width: 100%; height: auto; display: block; }
.t-kin { fill: none; stroke: rgba(158, 197, 244, 0.28); stroke-width: 1.3; }
.t-mar { stroke: rgba(158, 197, 244, 0.42); stroke-width: 1.5; }
.t-pair { fill: none; stroke: rgba(242, 179, 61, 0.45); stroke-width: 1.6; transition: stroke 0.3s, stroke-width 0.3s, opacity 0.3s; }
.t-pair.potential { stroke-dasharray: 2 5; stroke-linecap: round; }
.t-pair.engaged { stroke-dasharray: 7 5; }
.t-pair.both { stroke: #f2b33d; stroke-width: 4; stroke-dasharray: none; }
.t-pair.gone { opacity: 0.15; }
.t-node .shape { fill: #0b1b30; stroke: rgba(198, 211, 230, 0.6); stroke-width: 1.6; transition: fill 0.3s, stroke 0.3s, opacity 0.3s; }
.t-node.affected .shape { fill: #eef3fa; stroke: #eef3fa; }
.t-node.obligate .shape { fill: #2a3f5c; }
.t-node.deceased .shape, .t-node.unavailable .shape { stroke-dasharray: 3 3; stroke: rgba(158, 197, 244, 0.3); fill: transparent; }
.t-node .slash { stroke: rgba(158, 197, 244, 0.45); stroke-width: 1.4; }
.t-node.candidate { cursor: pointer; }
.t-node.candidate .shape { stroke: #a9c8ee; stroke-width: 2; }
.t-node.candidate:hover .shape, .t-node.candidate:focus-visible .shape { stroke: #fff; stroke-width: 2.6; }
.t-node.candidate:focus-visible { outline: none; }
.t-node.tested .shape { fill: #2a78d6; stroke: #86b6ef; }
.t-node.away .shape { fill: transparent; stroke: rgba(158, 197, 244, 0.35); stroke-dasharray: 3 3; }
.t-node.away .pv, .t-node.away .pl { opacity: 0.4; text-decoration: line-through; }
.t-node .pv { font-size: 9.5px; font-weight: 700; fill: #cfe0f6; text-anchor: middle; font-family: Inter, "Segoe UI", system-ui, sans-serif; pointer-events: none; }
.t-node.tested .pv { fill: #fff; }
.t-node .pl { font-size: 9.5px; fill: #a9bbd3; text-anchor: middle; font-family: Inter, "Segoe UI", system-ui, sans-serif; pointer-events: none; }
.t-node.tested .pl { fill: #fff; font-weight: 700; }
.t-node .pl.dim { fill: #7489a6; }
.plan-legend { display: flex; flex-wrap: wrap; gap: 6px 16px; font-size: 12px; color: var(--lab-ink-2); margin-top: 6px; }
.plan-legend span { display: inline-flex; align-items: center; gap: 6px; }
.lg { width: 12px; height: 12px; border-radius: 3px; display: inline-block; border: 1.6px solid #a9c8ee; }
.lg.tested { background: #2a78d6; border-color: #86b6ef; }
.lg.away { border-style: dashed; border-color: rgba(158, 197, 244, 0.4); }
.lg.pair { width: 18px; height: 0; border: 0; border-top: 3px solid #f2b33d; border-radius: 0; }
.plan-side { display: flex; flex-direction: column; gap: 12px; }
.kits { display: flex; align-items: center; gap: 10px; font-size: 14px; color: var(--lab-ink-2); }
.kits span { margin-right: auto; }
.kit-step { width: 38px; height: 38px; padding: 0; justify-content: center; font-size: 20px; line-height: 1; }
.kits output { font-size: 30px; font-weight: 800; color: var(--lab-ink); min-width: 1.2em; text-align: center; }
.plan-cards { display: grid; gap: 8px; }
.pcard { border: 1px solid var(--lab-line); border-radius: 12px; padding: 11px 13px; background: rgba(255, 255, 255, 0.025); }
.pcard.qaoa { border-color: rgba(134, 182, 239, 0.55); background: rgba(42, 120, 214, 0.14); }
.pc-head { display: flex; justify-content: space-between; gap: 10px; align-items: baseline; font-size: 14px; color: var(--lab-ink); }
.pc-pct { font-weight: 800; font-size: 18px; }
.pcard.qaoa .pc-pct { color: #fff; }
.pcard.field .pc-pct { color: var(--lab-ink-2); }
.pc-names { font-size: 13.5px; color: var(--lab-ink); margin-top: 3px; }
.pc-meta { font-size: 12px; color: var(--lab-ink-2); margin-top: 4px; line-height: 1.45; }
.pc-verdict { font-size: 13px; font-weight: 700; padding: 0 4px; margin: -2px 0 2px; }
.pc-verdict.ok { color: #7fd6a8; }
.pc-verdict.miss { color: var(--lab-best); }
#plan-restore { align-self: flex-start; }
@media (max-width: 980px) { .lab-plan { grid-template-columns: 1fr; } }

/* penalty against constrained */
.cmp-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; margin-top: 6px; }
.cmp-col { border: 1px solid var(--lab-line); border-radius: 12px; padding: 14px 16px; background: rgba(255, 255, 255, 0.025); }
.cmp-head { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 4px 12px; font-size: 14px; color: var(--lab-ink); }
.cmp-head span { font-size: 12.5px; color: var(--lab-ink-2); }
.cmp-bars { display: grid; grid-auto-flow: column; grid-auto-columns: minmax(0, 1fr); gap: 4px; height: 150px; margin: 14px 0 8px; }
.cmp-bar { display: grid; grid-template-rows: 16px 1fr 16px; align-items: end; text-align: center; }
.cmp-bar i { display: block; align-self: end; height: 0; background: #e26d3a; border-radius: 3px 3px 0 0; transition: height 0.6s cubic-bezier(0.2, 0.7, 0.2, 1); min-height: 1px; }
.cmp-bar.ok i { background: #2a78d6; }
.cmp-bar .cv { font-size: 10.5px; color: var(--lab-ink-2); font-variant-numeric: tabular-nums; align-self: end; }
.cmp-bar .ck { font-size: 11px; color: var(--lab-muted); align-self: start; border-top: 1px solid var(--lab-line); padding-top: 2px; }
.cmp-bar.ok .ck { color: var(--lab-ink); font-weight: 700; }
.cmp-kv { display: grid; grid-template-columns: 1fr auto; gap: 6px 12px; font-size: 13.5px; margin: 6px 0 0; }
.cmp-kv dt { color: var(--lab-ink-2); }
.cmp-kv dd { margin: 0; font-weight: 700; text-align: right; color: var(--lab-ink); font-variant-numeric: tabular-nums; }
#lab-compare .read-check { margin-top: 14px; }
@media (max-width: 760px) { .cmp-grid { grid-template-columns: 1fr; } }
/* On phones the tree keeps a size that can be read and tapped, and scrolls sideways inside its panel. */
@media (max-width: 560px) {
  .lab-plan { grid-template-columns: minmax(0, 1fr); }
  .plan-tree { min-width: 0; }
  #plan-svg { overflow-x: auto; -webkit-overflow-scrolling: touch; padding-bottom: 6px; }
  #plan-svg svg { width: 520px; max-width: none; }
}
@media (prefers-reduced-motion: reduce) { .cmp-bar i { transition: none; } }