:root {
  --space-unit: 4px;
  --space-fib-1: 4px;
  --space-fib-2: 8px;
  --space-fib-3: 12px;
  --space-fib-4: 20px;
  --space-fib-5: 32px;

  --surface-warm-100: #faf6f1;
  --surface-cool-200: #e8edf5;
  --hue-spirited-400: #6366f1;
  --hue-spirited-active: #818cf8;

  --grid-line: #6366f1;
  --grid-bg: #faf6f1;
  --text-primary: #1e1e2e;
  --text-muted: #94a3b8;

  --snap-easing: cubic-bezier(0.4, 0, 1, 1);
  --hold-window-ms: 300;
  --ship-threshold: 8;
}

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

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  font-family: -apple-system, system-ui, 'Inter', 'Helvetica Neue', sans-serif;
  background: var(--surface-warm-100);
  color: var(--text-primary);
}

#app {
  position: relative;
  display: flex;
  flex-direction: column;
  height: 100vh;
  width: 100vw;
  overflow: hidden;
}

/* ── Start Overlay ── */
.overlay {
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: rgba(10, 15, 30, 0.96);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: opacity 0.15s var(--snap-easing);
}

.overlay.hidden {
  opacity: 0;
  pointer-events: none;
}

.overlay-content {
  text-align: center;
  color: #fff;
  position: relative;
}

.overlay-content h1 {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 900;
  letter-spacing: -2px;
  margin-bottom: var(--space-fib-3);
}

.overlay-content p {
  font-size: 1rem;
  color: var(--surface-cool-200);
  font-weight: 500;
}

.pulse-ring {
  width: 120px;
  height: 120px;
  margin: var(--space-fib-5) auto 0;
  border-radius: 50%;
  border: 2px solid var(--hue-spirited-400);
  animation: pulse 1.2s var(--snap-easing) infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(0.8); opacity: 0.4; }
  50% { transform: scale(1.1); opacity: 1; }
}

/* ── HUD ── */
#hud {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 40px;
  padding: 0 var(--space-fib-4);
  background: rgba(10, 15, 30, 0.06);
  border-bottom: 1px solid rgba(99, 102, 241, 0.15);
  flex-shrink: 0;
}

.hud-left, .hud-right {
  display: flex;
  gap: var(--space-fib-3);
}

.hud-center {
  flex: 1;
  text-align: center;
}

.hud-label {
  font-size: 0.7rem;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.05em;
  color: var(--text-muted);
}

.hud-label span {
  color: var(--text-primary);
  font-weight: 800;
}

.phase-indicator {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 2px 10px;
  border-radius: 4px;
  transition: all 0.1s var(--snap-easing);
}

.phase-idle { color: var(--text-muted); }
.phase-hold { color: var(--hue-spirited-400); background: rgba(99, 102, 241, 0.1); }
.phase-locked { color: #22c55e; background: rgba(34, 197, 94, 0.1); }
.phase-drift { color: #ef4444; background: rgba(239, 68, 68, 0.1); }

/* ── Grid ── */
#grid-container {
  flex: 1;
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.grid-12c {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  grid-template-rows: repeat(1, 1fr);
  width: 94vw;
  height: 65vh;
  gap: 2px;
  align-items: center;
}

.grid-cell {
  border: 1px solid rgba(99, 102, 241, 0.12);
  background: transparent;
  transition: all 0.08s var(--snap-easing);
  position: relative;
  will-change: transform, background-color, border-color;
}

.grid-cell.active {
  background: rgba(99, 102, 241, 0.08);
  border-color: rgba(99, 102, 241, 0.35);
}

.grid-cell.pulse {
  background: rgba(99, 102, 241, 0.15);
  border-color: rgba(99, 102, 241, 0.6);
  transform: scaleY(1.02);
}

.grid-cell.locked {
  background: var(--surface-cool-200);
  border-color: var(--hue-spirited-400);
}

.grid-cell.drift {
  background: rgba(239, 68, 68, 0.1);
  border-color: rgba(239, 68, 68, 0.4);
  animation: drift-flash 0.2s var(--snap-easing);
}

@keyframes drift-flash {
  0% { transform: scale(1); }
  50% { transform: scale(0.97); background: rgba(239, 68, 68, 0.2); }
  100% { transform: scale(1); }
}

/* Scanline */
.scanline {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--hue-spirited-400), transparent);
  opacity: 0.7;
  z-index: 10;
  transition: top 0.08s linear;
  pointer-events: none;
}

/* ── Ship Footer ── */
#ship-footer {
  padding: var(--space-fib-3) var(--space-fib-4);
  flex-shrink: 0;
  background: rgba(10, 15, 30, 0.04);
  border-top: 1px solid rgba(99, 102, 241, 0.12);
}

.ship-bar-container {
  position: relative;
  width: 100%;
}

.ship-bar-track {
  width: 100%;
  height: 20px;
  background: rgba(99, 102, 241, 0.08);
  border: 1px solid rgba(99, 102, 241, 0.15);
  border-radius: 2px;
  overflow: hidden;
}

.ship-bar-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--hue-spirited-400), var(--hue-spirited-active));
  transition: width 0.15s var(--snap-easing);
  border-radius: 1px;
}

.ship-bar-fill.flipped {
  background: var(--hue-spirited-400);
  width: 100% !important;
  animation: ship-flip 0.3s var(--snap-easing);
}

@keyframes ship-flip {
  0% { transform: scaleY(1); }
  40% { transform: scaleY(1.6); }
  100% { transform: scaleY(1); }
}

.ship-label {
  text-align: center;
  font-size: 0.6rem;
  font-weight: 800;
  letter-spacing: 0.2em;
  color: var(--text-muted);
  margin-top: 4px;
  transition: all 0.15s var(--snap-easing);
}

.ship-label.flipped {
  color: var(--hue-spirited-400);
}

/* ── Break Room ── */
.break-room {
  position: fixed;
  inset: 0;
  z-index: 2000;
  background: rgba(10, 15, 30, 0.95);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: #fff;
  transition: opacity 0.2s var(--snap-easing);
}

.break-room.hidden {
  opacity: 0;
  pointer-events: none;
}

.break-room h2 {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 900;
  letter-spacing: -1px;
  margin-bottom: var(--space-fib-2);
}

.break-room p {
  font-size: 1rem;
  color: var(--surface-cool-200);
  font-weight: 500;
}

/* ── Responsive ── */
@media (max-width: 720px) {
  #hud { padding: 0 var(--space-fib-2); }
  .hud-label { font-size: 0.6rem; }
  .grid-12c { width: 98vw; height: 55vh; }
  #ship-footer { padding: var(--space-fib-2); }
  .ship-bar-track { height: 16px; }
}