:root {
  color-scheme: dark;
  --bg: #060914;
  --panel: rgba(15, 23, 42, 0.88);
  --line: rgba(148, 163, 184, 0.22);
  --text: #e8eefc;
  --muted: #94a3b8;
  --cyan: #67e8f9;
  --violet: #a78bfa;
  --green: #74f2a7;
  --red: #fb7185;
  --amber: #facc15;
}

* { box-sizing: border-box; }

html, body { min-height: 100%; margin: 0; }

body {
  color: var(--text);
  background:
    radial-gradient(circle at 10% 12%, rgba(103, 232, 249, 0.12), transparent 28rem),
    radial-gradient(circle at 88% 18%, rgba(167, 139, 250, 0.16), transparent 30rem),
    linear-gradient(135deg, #050816, #0b1020 54%, #111827);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

button, input, select { font: inherit; }
button { cursor: pointer; }

.lab-shell {
  width: min(1220px, calc(100% - 28px));
  margin: 0 auto;
  padding: 22px 0 56px;
}

.lab-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 18px;
}

.lab-header a {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 10px 14px;
  color: var(--cyan);
  background: rgba(255, 255, 255, 0.045);
  text-decoration: none;
  font-weight: 900;
}

.lab-header div { color: var(--muted); text-align: right; }
.lab-header span { display: block; color: var(--cyan); font-size: 0.78rem; font-weight: 900; letter-spacing: 0.18em; text-transform: uppercase; }

.intro-panel,
.control-strip,
.lab-grid > article {
  border: 1px solid var(--line);
  background: linear-gradient(145deg, rgba(15, 23, 42, 0.92), rgba(8, 13, 28, 0.88));
  box-shadow: 0 24px 58px rgba(0, 0, 0, 0.28);
  backdrop-filter: blur(18px);
}

.intro-panel {
  position: relative;
  overflow: hidden;
  border-radius: 30px;
  padding: clamp(28px, 5vw, 58px);
}

.intro-panel::after {
  position: absolute;
  right: -120px;
  top: -150px;
  width: 430px;
  aspect-ratio: 1;
  border-radius: 50%;
  content: "";
  background: radial-gradient(circle, rgba(103, 232, 249, 0.24), transparent 67%);
}

.kicker {
  margin: 0 0 10px;
  color: var(--cyan);
  font-size: 0.73rem;
  font-weight: 950;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

.intro-panel h1 {
  position: relative;
  margin: 0;
  max-width: 780px;
  font-size: clamp(3.4rem, 8vw, 7.2rem);
  letter-spacing: -0.075em;
  line-height: 0.86;
}

.intro-panel p:not(.kicker) {
  position: relative;
  max-width: 760px;
  margin: 22px 0 0;
  color: #c4d1e8;
  font-size: clamp(1rem, 1.45vw, 1.2rem);
  line-height: 1.62;
}

.control-strip {
  display: grid;
  grid-template-columns: 1.2fr 0.55fr 1fr auto;
  gap: 14px;
  align-items: end;
  margin-top: 16px;
  border-radius: 22px;
  padding: 18px;
}

label {
  display: grid;
  gap: 8px;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

select, input[type="number"] {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 12px;
  color: var(--text);
  background: rgba(5, 8, 22, 0.8);
}

input[type="range"] { accent-color: var(--cyan); }

#resetButton,
.decision-buttons button {
  border: 0;
  border-radius: 16px;
  min-height: 48px;
  padding: 12px 16px;
  color: #06101f;
  font-weight: 950;
}

#resetButton { background: linear-gradient(135deg, #cbd5e1, #94a3b8); }

.lab-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 16px;
}

.lab-grid > article {
  border-radius: 24px;
  padding: 22px;
}

.panel-heading h2 {
  margin: 0 0 18px;
  font-size: clamp(1.7rem, 2.8vw, 2.8rem);
  letter-spacing: -0.055em;
  line-height: 0.95;
}

.agent-brief, .round-outcome, .matrix-note, #feedbackText, .insight-stack article p {
  color: #bfcae0;
  line-height: 1.55;
}

.decision-buttons {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin: 20px 0;
}

.decision-buttons .cooperate { background: linear-gradient(135deg, var(--green), #22c55e); }
.decision-buttons .defect { background: linear-gradient(135deg, var(--red), #e11d48); color: #fff6f8; }

.round-outcome {
  border: 1px solid var(--line);
  border-radius: 18px;
  min-height: 110px;
  padding: 16px;
  background: rgba(255, 255, 255, 0.04);
}

.payoff-matrix {
  display: grid;
  grid-template-columns: 0.9fr 1fr 1fr;
  gap: 8px;
}

.axis,
.payoff-cell {
  min-height: 74px;
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 13px;
  display: grid;
  place-items: center;
  text-align: center;
}

.axis { color: var(--muted); background: rgba(255, 255, 255, 0.035); font-weight: 900; }
.payoff-cell { color: var(--text); background: rgba(103, 232, 249, 0.055); font-size: 1.45rem; font-weight: 950; }
.payoff-cell.active { outline: 2px solid var(--amber); box-shadow: 0 0 32px rgba(250, 204, 21, 0.22); }

.stat-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
}

.stat-grid div {
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 14px;
  background: rgba(255, 255, 255, 0.04);
}

.stat-grid span { display: block; color: var(--muted); font-size: 0.72rem; font-weight: 900; text-transform: uppercase; }
.stat-grid strong { display: block; margin-top: 8px; font-size: 1.8rem; letter-spacing: -0.06em; }

.history-chart {
  display: flex;
  align-items: end;
  gap: 7px;
  height: 170px;
  margin-top: 20px;
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 14px;
  background: linear-gradient(to top, rgba(103, 232, 249, 0.05), transparent);
}

.history-bar {
  flex: 1;
  min-width: 10px;
  border-radius: 8px 8px 2px 2px;
  background: var(--green);
}

.history-bar.defected { background: var(--red); }
.history-bar.mixed { background: linear-gradient(to top, var(--red) 50%, var(--green) 50%); }

.insight-stack {
  display: grid;
  gap: 10px;
  margin-top: 16px;
}

.insight-stack article {
  border-left: 3px solid var(--cyan);
  border-radius: 14px;
  padding: 12px 14px;
  background: rgba(103, 232, 249, 0.055);
}

.insight-stack h3 { margin: 0 0 6px; font-size: 1rem; }
.insight-stack p { margin: 0; }

@media (max-width: 980px) {
  .control-strip,
  .lab-grid,
  .stat-grid { grid-template-columns: 1fr; }
}

@media (max-width: 620px) {
  .lab-header { align-items: flex-start; flex-direction: column; }
  .lab-header div { text-align: left; }
  .intro-panel { padding: 26px; }
  .decision-buttons, .payoff-matrix { grid-template-columns: 1fr; }
  .payoff-matrix > div:first-child { display: none; }
}

button,
a {
  touch-action: manipulation;
}

@media (max-width: 760px) {
  body {
    overflow-x: hidden;
  }

  .lab-shell {
    width: min(100% - 18px, 1220px);
    padding: calc(10px + env(safe-area-inset-top)) 0 44px;
  }

  .control-strip {
    position: sticky;
    top: 0;
    z-index: 5;
    box-shadow: 0 18px 36px rgba(0, 0, 0, .28);
  }

  .lab-grid > article,
  .control-strip,
  .intro-panel {
    border-radius: 22px;
    padding: 18px;
  }

  .stat-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .history-chart {
    overflow-x: auto;
    align-items: stretch;
    height: 132px;
  }

  .history-bar {
    flex: 0 0 18px;
  }
}

@media (max-width: 460px) {
  .intro-panel h1 {
    font-size: clamp(2.9rem, 17vw, 4.4rem);
  }

  .decision-buttons button,
  #resetButton {
    width: 100%;
  }

  .payoff-matrix {
    gap: 6px;
  }

  .axis,
  .payoff-cell {
    min-height: 58px;
    padding: 10px;
    font-size: .95rem;
  }

  .payoff-cell {
    font-size: 1.2rem;
  }
}