:root {
  --bg-deep: #020617;
  --bg-panel: rgba(6, 10, 24, 0.78);
  --ice: #e0f7ff;
  --frost: #a5f3fc;
  --cyan: #00f5e1;
  --violet: #bc13fe;
  --slate: #64748b;
  --slate-dim: rgba(100, 116, 139, 0.65);
  --danger: #ff4d6d;
  --glass: rgba(255, 255, 255, 0.06);
  --font-display: "Orbitron", monospace;
  --font-body: "Nunito", system-ui, sans-serif;
  --radius: 14px;
  --transition: 240ms cubic-bezier(0.22, 1, 0.36, 1);
}

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

html,
body {
  height: 100%;
  overflow: hidden;
}

body {
  background: var(--bg-deep);
  color: var(--ice);
  font-family: var(--font-body);
  -webkit-font-smoothing: antialiased;
  user-select: none;
}

.game-stage {
  position: relative;
  width: 100vw;
  height: 100vh;
}

#game-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  cursor: crosshair;
}

/* ---- HUD ---- */
.hud {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  z-index: 20;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: start;
  padding: 28px 36px;
  gap: 20px;
  pointer-events: none;
}

.hud-block {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.hud-block--right {
  align-items: flex-end;
}

.hud-block--center {
  align-items: center;
}

.hud-row {
  position: absolute;
  top: 92px;
  left: 36px;
  right: 36px;
  display: flex;
  justify-content: space-between;
  pointer-events: none;
}

.hud-label {
  font-family: var(--font-body);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.28em;
  color: var(--slate-dim);
  text-transform: uppercase;
}

.hud-value {
  font-family: var(--font-display);
  font-size: 42px;
  font-weight: 700;
  line-height: 1;
  color: var(--ice);
  text-shadow: 0 0 20px rgba(0, 245, 225, 0.22);
}

.hud-value--small {
  font-size: 28px;
}

.logo {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  text-align: center;
}

.logo__main {
  font-family: var(--font-display);
  font-size: 34px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--ice);
  text-shadow: 0 0 30px rgba(0, 245, 225, 0.28);
}

.logo__sub {
  font-family: var(--font-body);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.4em;
  color: var(--slate-dim);
}

.hud-btn {
  position: absolute;
  top: 28px;
  right: 36px;
  pointer-events: auto;
  padding: 10px 22px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 6px;
  background: rgba(2, 6, 23, 0.55);
  color: var(--ice);
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.05em;
  cursor: pointer;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: border-color var(--transition), background var(--transition), transform var(--transition);
}

.hud-btn:hover {
  border-color: rgba(0, 245, 225, 0.45);
  background: rgba(0, 245, 225, 0.08);
  transform: translateY(-1px);
}

.hud-btn:active {
  transform: translateY(0);
}

/* ---- Overlays ---- */
.overlay {
  position: absolute;
  inset: 0;
  z-index: 30;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(2, 6, 23, 0.82);
  opacity: 0;
  visibility: hidden;
  transition: opacity 380ms ease, visibility 380ms ease;
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}

.overlay--active {
  opacity: 1;
  visibility: visible;
}

.overlay__panel {
  width: min(520px, 90vw);
  padding: 48px 42px;
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius);
  background: var(--bg-panel);
  box-shadow:
    0 24px 70px rgba(0, 0, 0, 0.45),
    inset 0 0 0 1px rgba(255, 255, 255, 0.04);
  text-align: center;
  transform: translateY(18px) scale(0.98);
  transition: transform 420ms cubic-bezier(0.34, 1.56, 0.64, 1);
}

.overlay__panel--compact {
  padding: 40px 36px;
}

.overlay--active .overlay__panel {
  transform: translateY(0) scale(1);
}

.overlay__kicker {
  font-family: var(--font-body);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.36em;
  text-transform: uppercase;
  color: var(--cyan);
  margin-bottom: 14px;
}

.overlay__kicker--alert {
  color: var(--danger);
}

.overlay__title {
  font-family: var(--font-display);
  font-size: 48px;
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: 0.04em;
  color: var(--ice);
  margin-bottom: 6px;
  text-shadow: 0 0 40px rgba(0, 245, 225, 0.25);
}

.overlay__subtitle {
  font-family: var(--font-body);
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 0.25em;
  color: var(--slate-dim);
  margin-bottom: 22px;
}

.overlay__copy {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  color: var(--slate-dim);
  margin-bottom: 26px;
}

.overlay__stat {
  color: var(--ice);
  font-weight: 700;
}

.overlay__controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-bottom: 32px;
  font-size: 13px;
  color: var(--slate-dim);
}

kbd {
  font-family: var(--font-body);
  font-size: 12px;
  font-weight: 700;
  padding: 6px 10px;
  border-radius: 5px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  background: rgba(255, 255, 255, 0.05);
  color: var(--ice);
}

/* ---- Buttons ---- */
.frost-btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 16px 44px;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  background: linear-gradient(135deg, rgba(0, 245, 225, 0.14), rgba(188, 19, 254, 0.14));
  color: var(--ice);
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition);
}

.frost-btn::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  border: 1px solid rgba(0, 245, 225, 0.35);
  pointer-events: none;
}

.frost-btn--secondary {
  background: linear-gradient(135deg, rgba(255, 77, 109, 0.12), rgba(188, 19, 254, 0.12));
}

.frost-btn--secondary::before {
  border-color: rgba(255, 77, 109, 0.35);
}

.frost-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 32px rgba(0, 245, 225, 0.14);
}

.frost-btn--secondary:hover {
  box-shadow: 0 12px 32px rgba(255, 77, 109, 0.14);
}

.frost-btn:active {
  transform: translateY(0);
}

.frost-btn__text {
  position: relative;
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

/* ---- Mobile tweaks ---- */
@media (max-width: 640px) {
  .hud {
    padding: 20px 22px;
    grid-template-columns: 1fr 1fr;
  }

  .hud-block--center {
    display: none;
  }

  .hud-block--right {
    align-items: flex-end;
  }

  .hud-value {
    font-size: 32px;
  }

  .hud-value--small {
    font-size: 22px;
  }

  .hud-row {
    top: 74px;
    left: 22px;
    right: 22px;
  }

  .hud-btn {
    top: auto;
    right: 22px;
    bottom: 22px;
  }

  .overlay__title {
    font-size: 36px;
  }

  .overlay__panel {
    padding: 36px 28px;
  }
}