:root {
  color-scheme: dark;
  --bg: #101514;
  --panel: #18211f;
  --panel-strong: #202b28;
  --text: #eef5f0;
  --muted: #9fb0aa;
  --accent: #e13f33;
  --accent-2: #46b980;
  --grid: #273531;
  --shadow: rgba(0, 0, 0, 0.35);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: radial-gradient(circle at 20% 10%, #21302c 0, transparent 32rem), var(--bg);
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

button {
  border: 0;
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  cursor: pointer;
  font: inherit;
  font-weight: 700;
}

button:hover,
button:focus-visible {
  filter: brightness(1.08);
}

button:disabled {
  cursor: not-allowed;
  filter: grayscale(0.8) brightness(0.62);
  opacity: 0.58;
}

.app {
  display: grid;
  min-height: 100vh;
  place-items: center;
  padding: 24px;
}

.game-shell {
  width: min(100%, 560px);
}

.topbar {
  align-items: end;
  display: flex;
  gap: 20px;
  justify-content: space-between;
  margin-bottom: 16px;
}

h1,
h2,
p {
  margin: 0;
}

h1 {
  font-size: clamp(2rem, 8vw, 4rem);
  line-height: 0.95;
}

.stats {
  display: grid;
  gap: 8px;
  grid-template-columns: repeat(2, minmax(76px, 1fr));
}

.stat {
  background: var(--panel);
  border: 1px solid #2b3935;
  border-radius: 8px;
  padding: 10px 12px;
  text-align: right;
}

.stat span {
  color: var(--muted);
  display: block;
  font-size: 0.75rem;
}

.stat strong {
  display: block;
  font-size: 1.45rem;
  line-height: 1.1;
}

.stage-bar {
  align-items: center;
  background: rgba(24, 33, 31, 0.82);
  border: 1px solid #33433e;
  border-radius: 8px;
  display: flex;
  gap: 10px;
  justify-content: space-between;
  margin-bottom: 12px;
  padding: 10px 12px;
}

.stage-bar label {
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 800;
}

.stage-bar select {
  background: #263531;
  border: 1px solid #41524d;
  border-radius: 8px;
  color: var(--text);
  font: inherit;
  min-height: 36px;
  padding: 0 10px;
  width: min(100%, 260px);
}

.board-wrap {
  aspect-ratio: 1;
  background:
    linear-gradient(135deg, rgba(70, 185, 128, 0.14), rgba(225, 63, 51, 0.08)),
    var(--panel-strong);
  border: 1px solid #33433e;
  border-radius: 8px;
  box-shadow: 0 22px 70px var(--shadow);
  overflow: hidden;
  position: relative;
  width: 100%;
}

canvas {
  display: block;
  height: 100%;
  width: 100%;
}

.graph-panel {
  background: rgba(24, 33, 31, 0.82);
  border: 1px solid #33433e;
  border-radius: 8px;
  margin-top: 12px;
  overflow: hidden;
}

.graph-head {
  align-items: center;
  border-bottom: 1px solid #2b3935;
  display: flex;
  justify-content: space-between;
  padding: 8px 12px;
}

.graph-head span {
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 800;
}

.graph-head strong {
  color: var(--accent-2);
  font-size: 0.85rem;
}

#exp-graph {
  height: 120px;
}

.overlay {
  align-items: center;
  background: rgba(12, 17, 16, 0.72);
  display: none;
  inset: 0;
  justify-content: center;
  padding: 24px;
  position: absolute;
}

.overlay.is-visible {
  display: flex;
}

.overlay-panel {
  background: rgba(24, 33, 31, 0.95);
  border: 1px solid #40504b;
  border-radius: 8px;
  box-shadow: 0 16px 48px var(--shadow);
  max-width: 280px;
  padding: 22px;
  text-align: center;
  width: 100%;
}

.overlay-panel h2 {
  font-size: 1.5rem;
  margin-bottom: 8px;
}

.overlay-panel p {
  color: var(--muted);
  font-size: 0.95rem;
  margin-bottom: 18px;
}

.overlay-panel button {
  min-height: 44px;
  margin-top: 8px;
  width: 100%;
}

.overlay-panel button:first-of-type {
  margin-top: 0;
}

.secondary-button {
  background: #263531;
  border: 1px solid #41524d;
}

.secondary-button.is-hidden {
  display: none;
}

.controls {
  display: none;
  gap: 8px;
  justify-content: center;
  margin-top: 16px;
}

.controls div {
  display: flex;
  gap: 8px;
}

.controls button {
  aspect-ratio: 1;
  background: #263531;
  border: 1px solid #41524d;
  font-size: 1.35rem;
  width: 56px;
}

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

  .topbar {
    align-items: stretch;
    flex-direction: column;
  }

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

  .controls {
    align-items: center;
    display: flex;
    flex-direction: column;
  }
}