:root {
  --lab-soil: #050b08;
  --lab-bark: #14261b;
  --lab-moss: #718268;
  --lab-lichen: #edf1e8;
  --lab-signal: #e2be67;
  --lab-denied: #d58a72;
}

.lab-page {
  background:
    linear-gradient(rgba(5, 11, 8, 0.93), rgba(5, 11, 8, 0.98)),
    url("/fig/shade-tree-banner.webp") center top / 100% auto no-repeat,
    var(--lab-soil);
}

.lab-page::before { display: none; }

.lab-page .site-nav { border-bottom-color: rgba(237, 241, 232, 0.13); }
.lab-page .nav-links a[aria-current="page"] { color: var(--lab-signal); }

.lab-main {
  width: min(86rem, calc(100vw - 3rem));
  margin: 0 auto;
  padding: clamp(4.5rem, 8vw, 8rem) 0 clamp(5rem, 9vw, 9rem);
}

.lab-intro {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(18rem, 0.65fr);
  gap: clamp(3rem, 8vw, 8rem);
  align-items: end;
  padding-bottom: clamp(3rem, 6vw, 5.5rem);
}

.lab-kicker,
.scenario-selector legend,
.passage-header span,
.fixture-note,
.no-network,
.trace-clock,
.trace-detail > span,
.result-heading > span {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.lab-kicker {
  margin: 0 0 1.5rem;
  color: var(--lab-signal);
}

.lab-intro h1 {
  max-width: 10ch;
  margin: 0;
  color: var(--lab-lichen);
  font-family: var(--display);
  font-size: clamp(3.8rem, 7.5vw, 7.9rem);
  font-weight: 520;
  line-height: 0.88;
  letter-spacing: -0.07em;
}

.lab-brief {
  display: grid;
  gap: 1.5rem;
  max-width: 34rem;
  padding-bottom: 0.8rem;
}

.lab-brief p {
  margin: 0;
  color: rgba(237, 241, 232, 0.78);
  font-size: clamp(1rem, 1.5vw, 1.25rem);
}

.lab-brief .fixture-note {
  padding-left: 1rem;
  color: rgba(237, 241, 232, 0.53);
  border-left: 1px solid var(--lab-signal);
  line-height: 1.7;
  text-transform: none;
  letter-spacing: 0.02em;
}

.fixture-note strong { color: var(--lab-lichen); }

.lab-workbench {
  display: grid;
  grid-template-columns: minmax(15rem, 19rem) minmax(0, 1fr);
  min-height: 43rem;
  border-top: 1px solid rgba(237, 241, 232, 0.24);
  border-bottom: 1px solid rgba(237, 241, 232, 0.24);
}

.scenario-selector {
  display: flex;
  flex-direction: column;
  padding: 2.4rem 2rem 2rem 0;
  border-right: 1px solid rgba(237, 241, 232, 0.17);
}

.scenario-selector fieldset {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  border: 0;
}

.scenario-selector legend {
  width: 100%;
  margin-bottom: 1.4rem;
  color: rgba(237, 241, 232, 0.52);
}

.scenario-selector label {
  position: relative;
  display: grid;
  grid-template-columns: 1rem 1fr;
  gap: 0.8rem;
  min-height: 4.6rem;
  align-items: center;
  padding: 0.85rem 0;
  color: rgba(237, 241, 232, 0.58);
  border-top: 1px solid rgba(237, 241, 232, 0.1);
  cursor: pointer;
}

.scenario-selector label:last-of-type { border-bottom: 1px solid rgba(237, 241, 232, 0.1); }

.scenario-selector input {
  width: 0.85rem;
  height: 0.85rem;
  margin: 0;
  appearance: none;
  border: 1px solid var(--lab-moss);
  border-radius: 50%;
}

.scenario-selector input:checked {
  background: var(--lab-signal);
  border-color: var(--lab-signal);
  box-shadow: 0 0 0 4px rgba(226, 190, 103, 0.12);
}

.scenario-selector label:has(input:checked) { color: var(--lab-lichen); }
.scenario-selector label span { display: grid; gap: 0.18rem; }
.scenario-selector label strong { font-size: 0.86rem; font-weight: 570; }
.scenario-selector label small { color: rgba(237, 241, 232, 0.42); font-size: 0.7rem; }

.walk-button {
  display: flex;
  width: 100%;
  min-height: 3.2rem;
  align-items: center;
  justify-content: space-between;
  margin-top: auto;
  padding: 0.8rem 0;
  color: var(--lab-signal);
  background: transparent;
  border: 0;
  border-bottom: 1px solid var(--lab-signal);
  cursor: pointer;
}

.walk-button:hover { color: var(--lab-lichen); }

.no-network {
  display: flex;
  gap: 0.55rem;
  align-items: center;
  margin: 1rem 0 0;
  color: rgba(237, 241, 232, 0.4);
  letter-spacing: 0.03em;
  text-transform: none;
}

.no-network span {
  width: 0.42rem;
  height: 0.42rem;
  background: var(--lab-moss);
  border-radius: 50%;
}

.passage {
  position: relative;
  display: grid;
  grid-template-rows: auto minmax(19rem, 1fr) auto;
  min-width: 0;
  padding: 2.4rem 0 2.4rem 2.6rem;
}

.passage-header {
  display: flex;
  gap: 2rem;
  align-items: start;
  justify-content: space-between;
}

.passage-header > div { display: grid; gap: 0.45rem; }
.passage-header span { color: var(--lab-signal); }

.passage-header h2 {
  margin: 0;
  color: var(--lab-lichen);
  font-family: var(--display);
  font-size: clamp(1.8rem, 3.3vw, 3.5rem);
  font-weight: 520;
  letter-spacing: -0.045em;
}

.trace-clock {
  min-width: 6.4rem;
  padding: 0.5rem 0;
  color: rgba(237, 241, 232, 0.46);
  text-align: right;
}

.passage-map {
  position: relative;
  min-height: 21rem;
  margin-top: 1rem;
  overflow: hidden;
}

.passage-map::before {
  position: absolute;
  inset: 7% 0 0;
  content: "";
  pointer-events: none;
  background:
    repeating-linear-gradient(90deg, transparent 0 8.2%, rgba(113, 130, 104, 0.06) 8.2% 8.35%),
    linear-gradient(180deg, transparent 72%, rgba(20, 38, 27, 0.28));
}

.route-line {
  position: absolute;
  inset: 1.5rem 0 0;
  width: 100%;
  height: calc(100% - 1.5rem);
  overflow: visible;
}

.route-line path { fill: none; vector-effect: non-scaling-stroke; }
.route-shadow { stroke: rgba(113, 130, 104, 0.2); stroke-width: 1.5; stroke-dasharray: 1 2; }
.route-progress {
  stroke: var(--lab-signal);
  stroke-width: 2.5;
  stroke-linecap: round;
  stroke-dasharray: 100;
  stroke-dashoffset: calc(100 - var(--route-progress, 0));
  filter: drop-shadow(0 0 8px rgba(226, 190, 103, 0.45));
  transition: stroke-dashoffset 620ms cubic-bezier(0.22, 0.75, 0.2, 1), stroke 180ms ease;
}

.passage-map[data-result="denied"] .route-progress { stroke: var(--lab-denied); }

.route-stages {
  position: absolute;
  inset: 0;
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 1.2rem;
  align-items: start;
  margin: 0;
  padding: 0;
  list-style: none;
}

.route-stages li {
  display: grid;
  gap: 0.75rem;
  align-content: start;
  color: rgba(237, 241, 232, 0.34);
}

.route-stages li:nth-child(even) { padding-top: 10.5rem; }
.route-stages li:nth-child(3) { padding-top: 3rem; }
.route-stages li:nth-child(5) { padding-top: 7.8rem; }

.stage-mark {
  display: grid;
  width: 2rem;
  height: 2rem;
  place-items: center;
  color: var(--lab-soil);
  background: var(--lab-moss);
  border: 5px solid rgba(5, 11, 8, 0.78);
  border-radius: 50%;
  font-family: var(--mono);
  font-size: 0.6rem;
  transition: background 180ms ease, box-shadow 180ms ease, transform 180ms ease;
}

.route-stages li > div { display: grid; gap: 0.3rem; max-width: 12rem; }
.route-stages strong { color: inherit; font-size: 0.8rem; font-weight: 620; }
.route-stages li > div span { font-size: 0.7rem; line-height: 1.45; }

.route-stages li[data-state="active"],
.route-stages li[data-state="passed"] { color: rgba(237, 241, 232, 0.84); }

.route-stages li[data-state="active"] .stage-mark,
.route-stages li[data-state="passed"] .stage-mark {
  background: var(--lab-signal);
  box-shadow: 0 0 0 7px rgba(226, 190, 103, 0.08), 0 0 18px rgba(226, 190, 103, 0.32);
}

.route-stages li[data-state="active"] .stage-mark { transform: scale(1.14); }
.route-stages li[data-state="denied"] { color: var(--lab-denied); }
.route-stages li[data-state="denied"] .stage-mark { background: var(--lab-denied); box-shadow: 0 0 0 7px rgba(213, 138, 114, 0.08); }

.trace-detail {
  display: grid;
  grid-template-columns: 8rem minmax(0, 1fr);
  gap: 1rem;
  min-height: 4rem;
  align-items: start;
  padding-top: 1.1rem;
  border-top: 1px solid rgba(237, 241, 232, 0.14);
}

.trace-detail > span { color: rgba(237, 241, 232, 0.46); }
.trace-detail p { max-width: 58ch; margin: 0; color: rgba(237, 241, 232, 0.76); font-size: 0.86rem; }

.passage-result {
  position: absolute;
  z-index: 4;
  right: 0;
  bottom: 2.4rem;
  left: 2.6rem;
  display: grid;
  grid-template-columns: minmax(13rem, 0.75fr) minmax(16rem, 1fr);
  gap: 1.5rem 3rem;
  padding: clamp(1.5rem, 3vw, 2.5rem);
  background: rgba(10, 25, 18, 0.96);
  border-top: 1px solid var(--lab-signal);
  box-shadow: 0 -2rem 5rem rgba(5, 11, 8, 0.74);
}

.passage-result[hidden] { display: none; }
.result-heading { display: grid; align-content: start; gap: 0.55rem; }
.result-heading > span { color: var(--lab-signal); }
.passage-result[data-outcome="denied"] { border-top-color: var(--lab-denied); }
.passage-result[data-outcome="denied"] .result-heading > span { color: var(--lab-denied); }

.result-heading h3 {
  max-width: 13ch;
  margin: 0;
  color: var(--lab-lichen);
  font-family: var(--display);
  font-size: clamp(1.7rem, 3vw, 2.8rem);
  font-weight: 520;
  line-height: 0.98;
  letter-spacing: -0.045em;
}

.passage-result ul {
  display: grid;
  gap: 0.55rem;
  margin: 0;
  padding: 0;
  color: rgba(237, 241, 232, 0.78);
  list-style: none;
  font-size: 0.82rem;
}

.passage-result li::before { margin-right: 0.65rem; color: var(--lab-signal); content: "+"; font-family: var(--mono); }
.passage-result[data-outcome="denied"] li::before { color: var(--lab-denied); content: "×"; }

.result-boundary {
  grid-column: 2;
  margin: 0;
  color: rgba(237, 241, 232, 0.42);
  font-size: 0.72rem;
}

.result-actions {
  display: flex;
  grid-column: 1 / -1;
  flex-wrap: wrap;
  gap: 0.6rem 1.4rem;
  align-items: center;
  padding-top: 1rem;
  border-top: 1px solid rgba(237, 241, 232, 0.14);
}

.result-actions button,
.result-actions a {
  min-height: 2.75rem;
  padding: 0.65rem 0;
  color: rgba(237, 241, 232, 0.7);
  background: transparent;
  border: 0;
  border-bottom: 1px solid rgba(237, 241, 232, 0.22);
  cursor: pointer;
}

.result-actions button:first-child { color: var(--lab-signal); border-bottom-color: var(--lab-signal); }
.result-actions a { margin-left: auto; color: var(--lab-lichen); }
.result-actions button:hover, .result-actions a:hover { color: var(--lab-lichen); }

.lab-boundaries {
  display: grid;
  grid-template-columns: minmax(12rem, 0.4fr) minmax(0, 1fr);
  gap: 3rem;
  padding-top: clamp(3rem, 6vw, 5rem);
}

.lab-boundaries h2 {
  max-width: 12ch;
  margin: 0;
  color: var(--lab-lichen);
  font-family: var(--display);
  font-size: clamp(1.8rem, 3vw, 3rem);
  font-weight: 520;
  line-height: 1;
  letter-spacing: -0.04em;
}

.lab-boundaries dl { display: grid; margin: 0; }
.lab-boundaries dl > div { display: grid; grid-template-columns: minmax(8rem, 0.35fr) minmax(0, 1fr); gap: 1rem; padding: 1rem 0; border-top: 1px solid rgba(237, 241, 232, 0.13); }
.lab-boundaries dt { color: var(--lab-signal); font-family: var(--mono); font-size: 0.7rem; text-transform: uppercase; letter-spacing: 0.08em; }
.lab-boundaries dd { max-width: 60ch; margin: 0; color: rgba(237, 241, 232, 0.65); font-size: 0.83rem; }

@media (max-width: 980px) {
  .lab-main { width: min(100% - 2rem, 50rem); }
  .lab-intro { grid-template-columns: 1fr; gap: 2.2rem; }
  .lab-brief { padding: 0; }
  .lab-workbench { grid-template-columns: 1fr; }
  .scenario-selector { padding: 1.8rem 0; border-right: 0; border-bottom: 1px solid rgba(237, 241, 232, 0.17); }
  .scenario-selector fieldset { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 1.5rem; }
  .scenario-selector legend { grid-column: 1 / -1; }
  .walk-button { margin-top: 1.5rem; }
  .passage { min-height: 40rem; padding-left: 0; }
  .passage-result { left: 0; }
}

@media (max-width: 650px) {
  .lab-page .site-nav { align-items: center; }
  .lab-page .nav-links { gap: 0.25rem; }
  .lab-page .nav-links a:nth-child(3) { display: none; }
  .lab-main { width: min(100% - 1.5rem, 38rem); padding-top: 3.5rem; }
  .lab-intro h1 { font-size: clamp(3.4rem, 17vw, 5rem); }
  .scenario-selector fieldset { grid-template-columns: 1fr; }
  .scenario-selector label { min-height: 3.9rem; }
  .passage { grid-template-rows: auto auto auto; min-height: 0; padding: 2rem 0; }
  .passage-header { gap: 1rem; }
  .trace-clock { min-width: 4rem; }
  .passage-map { min-height: 34rem; margin: 1.8rem 0 0 0.95rem; overflow: visible; }
  .passage-map::before, .route-line { display: none; }
  .route-stages { position: relative; display: grid; grid-template-columns: 1fr; gap: 0; padding-left: 1.35rem; border-left: 1px dashed rgba(113, 130, 104, 0.4); }
  .route-stages li, .route-stages li:nth-child(even), .route-stages li:nth-child(3), .route-stages li:nth-child(5) { grid-template-columns: 2rem 1fr; gap: 0.8rem; min-height: 6.5rem; padding: 0; }
  .stage-mark { margin-left: -2.4rem; }
  .route-stages li > div { max-width: none; }
  .trace-detail { grid-template-columns: 1fr; min-height: 6rem; }
  .passage-result { position: relative; right: auto; bottom: auto; left: auto; grid-template-columns: 1fr; margin-top: 1.5rem; box-shadow: none; }
  .result-boundary { grid-column: 1; }
  .result-actions { grid-column: 1; align-items: stretch; flex-direction: column; }
  .result-actions button, .result-actions a { width: 100%; margin-left: 0; text-align: left; }
  .lab-boundaries { grid-template-columns: 1fr; gap: 2rem; }
  .lab-boundaries dl > div { grid-template-columns: 1fr; gap: 0.4rem; }
}

@media (prefers-reduced-motion: reduce) {
  .route-progress, .stage-mark { transition: none; }
}