* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue",
    Arial, "Noto Sans JP", sans-serif;
  background: radial-gradient(1000px 700px at 10% -10%, #16203a 0%, transparent 60%),
    radial-gradient(800px 500px at 100% 0%, #2a1b41 0%, transparent 55%),
    #0b0d12;
  color: #e6e9ef;
  line-height: 1.6;
}

.wrap {
  max-width: 1000px;
  margin: 0 auto;
  padding: 18px;
}

.top h1 {
  margin: 0 0 6px;
  font-size: clamp(22px, 3vw, 32px);
}

.top p {
  margin: 0 0 12px;
  color: #a9b0bf;
}

.layout {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(0, 1.4fr);
  gap: 16px;
}

.game-panel {
  background: #111520;
  border-radius: 18px;
  border: 1px solid rgba(255, 255, 255, 0.06);
  padding: 12px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
}

canvas#game {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 12px;
  background: #05060a;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.ui {
  margin-top: 10px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  flex-wrap: wrap;
  font-size: 14px;
}

#startButton {
  padding: 8px 14px;
  border-radius: 999px;
  border: 1px solid rgba(125, 211, 252, 0.6);
  background: linear-gradient(
    90deg,
    rgba(125, 211, 252, 0.15),
    rgba(167, 139, 250, 0.15)
  );
  color: #e6e9ef;
  font-weight: 700;
  cursor: pointer;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.35);
}

#startButton:hover {
  transform: translateY(-1px);
  border-color: rgba(255, 255, 255, 0.8);
}

.info {
  background: #111520;
  border-radius: 18px;
  border: 1px solid rgba(255, 255, 255, 0.06);
  padding: 12px;
  font-size: 14px;
  color: #a9b0bf;
}

.info h2 {
  margin: 0 0 6px;
  font-size: 16px;
  color: #e6e9ef;
}

.info ul {
  margin: 0 0 10px 18px;
  padding: 0;
}

.note {
  font-size: 12px;
  opacity: 0.9;
}

/* スマホ向けレイアウト */
@media (max-width: 780px) {
  .layout {
    grid-template-columns: 1fr;
  }
}