* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  color-scheme: dark;
  --bg: #070708;
  --panel: #101115;
  --panel-border: #1c1d22;
  --accent: #67e8f9;
  --text: #e6e6e6;
  --muted: #8c8c8c;
}

body {
  font-family: "Segoe UI", "Noto Sans JP", system-ui, sans-serif;
  background: radial-gradient(circle at top, #11121a 0%, #050506 60%);
  color: var(--text);
  min-height: 100vh;
}

.page {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px;
}

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

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  letter-spacing: 0.18em;
  font-weight: 600;
}

.brand__dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 14px rgba(103, 232, 249, 0.7);
}

.status {
  display: flex;
  gap: 18px;
  font-size: 0.95rem;
  color: var(--muted);
}

.status__item span {
  color: var(--text);
  font-weight: 600;
  margin-left: 6px;
}

.main {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 260px;
  gap: 18px;
}

.game-panel {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: 18px;
  padding: 18px;
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.45);
}

canvas {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 12px;
  background: radial-gradient(circle at 50% 20%, #1d1f29 0%, #0b0c10 70%);
  border: 1px solid #181a21;
}

.overlay {
  position: absolute;
  inset: 18px;
  display: grid;
  place-items: center;
  background: rgba(8, 8, 10, 0.8);
  border-radius: 12px;
  backdrop-filter: blur(4px);
}

.overlay.hidden {
  display: none;
}

.overlay__card {
  text-align: center;
  max-width: 360px;
  padding: 24px;
  border-radius: 14px;
  border: 1px solid #20232c;
  background: rgba(10, 10, 12, 0.95);
  box-shadow: 0 0 40px rgba(0, 0, 0, 0.6);
}

.overlay__card h1 {
  font-size: 1.8rem;
  margin-bottom: 10px;
  letter-spacing: 0.08em;
}

.overlay__card p {
  color: var(--muted);
  margin-bottom: 18px;
}

.level-picker {
  display: grid;
  gap: 8px;
  margin-bottom: 16px;
  text-align: left;
}

.level-picker label {
  font-size: 0.75rem;
  color: var(--muted);
  letter-spacing: 0.18em;
}

.level-picker select {
  width: 100%;
  background: #0b0c10;
  color: var(--text);
  border: 1px solid #1e222b;
  border-radius: 10px;
  padding: 10px 12px;
  font-size: 0.95rem;
}

.overlay__hint {
  font-size: 0.85rem;
}

.btn {
  border: none;
  border-radius: 999px;
  padding: 12px 28px;
  background: var(--accent);
  color: #0a0a0a;
  font-weight: 700;
  letter-spacing: 0.12em;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 18px rgba(103, 232, 249, 0.35);
}

.info-panel {
  background: rgba(12, 12, 14, 0.7);
  border: 1px solid var(--panel-border);
  border-radius: 18px;
  padding: 18px;
  font-size: 0.95rem;
  color: var(--muted);
}

.info-panel h2 {
  font-size: 1rem;
  margin-bottom: 12px;
  color: var(--text);
  letter-spacing: 0.12em;
}

.info-panel ul {
  display: grid;
  gap: 10px;
  list-style: none;
}

@media (max-width: 980px) {
  .main {
    grid-template-columns: 1fr;
  }

  .info-panel {
    order: 2;
  }
}

@media (max-width: 640px) {
  .page {
    padding: 16px;
  }

  .header {
    flex-direction: column;
    align-items: flex-start;
  }

  .status {
    flex-wrap: wrap;
    gap: 10px 16px;
  }
}