:root {
  --bg-1: #070b1a;
  --bg-2: #101a2d;
  --panel: rgba(14, 22, 38, 0.92);
  --panel-border: rgba(255, 255, 255, 0.08);
  --text: #e8eefb;
  --muted: #9db0d1;
  --accent: #7ee7ff;
  --accent-strong: #4dc4ff;
  --shadow: rgba(0, 0, 0, 0.35);
  --grid: rgba(255, 255, 255, 0.05);
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  min-height: 100%;
  font-family: "Segoe UI", sans-serif;
  background: radial-gradient(circle at top, #142542 0%, var(--bg-1) 50%, #040915 100%);
  color: var(--text);
}

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

button {
  font: inherit;
}

.page-shell {
  width: min(980px, 100%);
}

.game-panel {
  background: rgba(19, 29, 48, 0.86);
  border: 1px solid var(--panel-border);
  border-radius: 20px;
  box-shadow: 0 30px 50px var(--shadow);
  padding: 22px 24px 18px;
  backdrop-filter: blur(8px);
}

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

.eyebrow {
  margin: 0 0 4px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  font-size: 0.7rem;
  color: var(--muted);
}

h1, h2 {
  margin: 0;
  letter-spacing: 0.04em;
}

h1 {
  font-size: clamp(2rem, 3vw, 3rem);
}

.menu-button,
.action-button {
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: linear-gradient(180deg, rgba(150, 204, 255, 0.18), rgba(95, 132, 176, 0.12));
  color: var(--text);
  border-radius: 10px;
  cursor: pointer;
  transition: transform 0.15s ease, border-color 0.15s ease, box-shadow 0.15s ease;
}

.menu-button {
  min-width: 110px;
  padding: 10px 16px;
}

.action-button {
  width: 100%;
  padding: 12px 14px;
  margin-bottom: 10px;
}

.menu-button:hover,
.action-button:hover,
.menu-button:focus-visible,
.action-button:focus-visible {
  transform: translateY(-1px);
  border-color: rgba(126, 231, 255, 0.6);
  box-shadow: 0 0 0 3px rgba(77, 196, 255, 0.2);
  outline: none;
}

.primary {
  background: linear-gradient(180deg, rgba(77, 196, 255, 0.3), rgba(27, 85, 146, 0.35));
}

.game-layout {
  display: grid;
  grid-template-columns: minmax(0, 300px) minmax(220px, 260px);
  gap: 26px;
  align-items: start;
}

#gameCanvas,
#nextCanvas {
  display: block;
  width: 100%;
  background: linear-gradient(180deg, rgba(9, 14, 28, 0.98), rgba(12, 22, 36, 0.98));
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 14px;
  box-shadow: inset 0 0 10px rgba(126, 231, 255, 0.08);
}

#gameCanvas {
  max-width: 300px;
}

.sidebar {
  display: grid;
  gap: 14px;
}

.stat-box,
.preview-box,
.controls-box {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: 12px;
  padding: 12px 14px;
}

.stat-box {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
}

.label {
  color: var(--muted);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.stat-box strong {
  font-size: 1.5rem;
  font-weight: 700;
}

.preview-box {
  display: grid;
  gap: 10px;
}

#nextCanvas {
  max-width: 120px;
  margin: 0 auto;
}

.controls-box ul {
  list-style: none;
  margin: 12px 0 0;
  padding: 0;
  display: grid;
  gap: 8px;
  color: var(--text);
}

.controls-box li {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  font-size: 0.92rem;
  color: var(--muted);
}

.controls-box li span {
  color: var(--text);
  font-weight: 600;
}

.overlay {
  position: fixed;
  inset: 0;
  display: none;
  place-items: center;
  background: rgba(7, 11, 26, 0.72);
  backdrop-filter: blur(6px);
  z-index: 1000;
}

.overlay.visible {
  display: grid;
}

.overlay-card {
  width: min(420px, calc(100vw - 32px));
  background: rgba(10, 18, 30, 0.95);
  border: 1px solid rgba(126, 231, 255, 0.22);
  border-radius: 16px;
  padding: 26px 22px 18px;
  text-align: center;
  box-shadow: 0 40px 60px rgba(0, 0, 0, 0.4);
}

.menu-actions {
  display: grid;
  gap: 8px;
  margin-top: 18px;
}

.menu-hint {
  margin: 16px 0 0;
  color: var(--muted);
  line-height: 1.5;
}

@media (max-width: 760px) {
  body {
    padding: 14px;
  }

  .game-panel {
    padding: 16px 14px 16px;
  }

  .game-layout {
    grid-template-columns: 1fr;
  }

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

  .menu-button {
    width: 100%;
  }
}