:root {
  color-scheme: dark;
  --ink: #f7fbff;
  --muted: rgba(247, 251, 255, 0.72);
  --edge: rgba(255, 255, 255, 0.18);
  --panel: rgba(10, 14, 22, 0.68);
  --ready: #21b06f;
  --signal: #ef3d34;
  --idle: #172033;
  --warn: #e0a326;
}

* {
  box-sizing: border-box;
}

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

body {
  display: grid;
  min-height: 100vh;
  place-items: center;
  background: #0b0f18;
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

button {
  min-width: 150px;
  min-height: 48px;
  border: 1px solid rgba(255, 255, 255, 0.32);
  border-radius: 8px;
  background: #ffffff;
  color: #111722;
  cursor: pointer;
  font: inherit;
  font-size: 1rem;
  font-weight: 900;
  transition: transform 120ms ease, box-shadow 120ms ease;
}

button:hover {
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.24);
}

button:active {
  transform: translateY(1px);
}

.game-shell {
  display: grid;
  gap: 14px;
  width: min(100vw - 28px, 980px);
}

.reaction-stage {
  position: relative;
  display: grid;
  min-height: min(72vh, 620px);
  overflow: hidden;
  border: 1px solid var(--edge);
  border-radius: 8px;
  background: var(--idle);
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.4);
  transition: background 160ms ease;
  user-select: none;
}

.reaction-stage.is-waiting {
  background: var(--ready);
}

.reaction-stage.is-signal {
  background: var(--signal);
}

.reaction-stage.is-early {
  background: var(--warn);
}

.reaction-stage.is-result {
  background: #263d78;
}

.stats {
  position: absolute;
  top: 14px;
  left: 14px;
  right: 14px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.stats div,
.history {
  border: 1px solid var(--edge);
  border-radius: 8px;
  background: var(--panel);
  backdrop-filter: blur(14px);
}

.stats div {
  padding: 11px 13px;
}

.stats span {
  display: block;
  color: var(--muted);
  font-size: 0.76rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.stats strong {
  display: block;
  min-height: 1.25em;
  font-size: clamp(1.12rem, 3vw, 1.8rem);
  line-height: 1.1;
}

.readout {
  display: grid;
  align-self: center;
  justify-items: center;
  max-width: 720px;
  margin: 70px auto 38px;
  padding: 28px;
  text-align: center;
}

.eyebrow {
  margin: 0 0 8px;
  color: rgba(255, 255, 255, 0.82);
  font-size: 0.82rem;
  font-weight: 900;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: clamp(3.2rem, 14vw, 9rem);
  line-height: 0.92;
}

p {
  margin: 18px 0 26px;
  max-width: 46rem;
  color: rgba(255, 255, 255, 0.86);
  font-size: clamp(1rem, 2.4vw, 1.28rem);
  line-height: 1.45;
}

.history {
  min-height: 58px;
  padding: 10px;
}

.history-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  margin-bottom: 10px;
}

.history-actions button {
  min-width: 132px;
  min-height: 40px;
  background: rgba(255, 255, 255, 0.1);
  color: var(--ink);
}

.attempts {
  display: flex;
  min-height: 38px;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.attempt {
  border: 1px solid var(--edge);
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.1);
  color: var(--ink);
  font-weight: 900;
  padding: 8px 11px;
}

.save-status {
  min-height: 1.3em;
  margin: 8px 0 0;
  max-width: none;
  color: var(--muted);
  font-size: 0.92rem;
  text-align: center;
}

@media (max-width: 640px) {
  body {
    padding: 14px 0;
  }

  .game-shell {
    width: min(100vw - 18px, 980px);
  }

  .reaction-stage {
    min-height: 70vh;
  }

  .stats {
    grid-template-columns: 1fr;
  }

  .readout {
    margin-top: 170px;
    padding-inline: 18px;
  }
}