:root {
  --bg:         #0f0e17;
  --surface:    #1a1a2e;
  --grid:       rgba(255, 255, 255, 0.12);
  --x-color:    #ff6b6b;
  --o-color:    #4ecdc4;
  --primary:    #7c4dff;
  --primary-h:  #9d6eff;
  --text:       #fffffe;
  --text-dim:   #a7a9be;
  --cell-size:  100px;
  --gap:        4px;
  --radius:     12px;
}

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

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Segoe UI', system-ui, sans-serif;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

/* ── Screens ───────────────────────────────────────────────────────────── */
.screen {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  opacity: 0;
  transform: translateY(24px);
  pointer-events: none;
  transition: opacity 0.35s ease, transform 0.35s ease;
}

.screen.active {
  opacity: 1;
  transform: translateY(0);
  pointer-events: all;
}

/* ── Buttons ───────────────────────────────────────────────────────────── */
.btn {
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: var(--radius);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.12s ease, box-shadow 0.12s ease, background 0.12s ease;
  letter-spacing: 0.04em;
}

.btn:active { transform: scale(0.95) !important; }

.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 4px 20px rgba(124, 77, 255, 0.35);
}
.btn-primary:hover {
  background: var(--primary-h);
  transform: translateY(-2px);
  box-shadow: 0 6px 26px rgba(124, 77, 255, 0.5);
}

.btn-secondary {
  background: var(--surface);
  color: var(--text);
  border: 1px solid rgba(255, 255, 255, 0.1);
}
.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.08);
  transform: translateY(-2px);
}

.btn-ghost {
  background: transparent;
  color: var(--text-dim);
}
.btn-ghost:hover { color: var(--text); }

.btn-small {
  padding: 0.35rem 0.75rem;
  font-size: 0.82rem;
  background: transparent;
  color: var(--text-dim);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 8px;
}
.btn-small:hover { color: var(--text); background: rgba(255, 255, 255, 0.06); }

.hidden { display: none !important; }

/* ── Menu Screen ───────────────────────────────────────────────────────── */
.menu-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2.5rem;
}

.title {
  font-size: clamp(3rem, 8vw, 5rem);
  font-weight: 900;
  letter-spacing: 0.08em;
  line-height: 0.95;
  text-align: center;
  background: linear-gradient(135deg, var(--x-color) 0%, var(--primary) 50%, var(--o-color) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: float 3.2s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0px); }
  50%       { transform: translateY(-10px); }
}

.menu-buttons {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
  width: 200px;
}

/* ── Board Screen ──────────────────────────────────────────────────────── */
.board-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: calc(var(--cell-size) * 3 + var(--gap) * 2 + 8px);
}

#game-info {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

#turn-label {
  font-size: 0.9rem;
  color: var(--text-dim);
  font-weight: 500;
}

.level-badge {
  padding: 0.2rem 0.55rem;
  border-radius: 20px;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.level-1 { background: rgba(78,205,196,0.15); color: var(--o-color); border: 1px solid var(--o-color); }
.level-2 { background: rgba(255,193,7,0.15);  color: #ffc107;         border: 1px solid #ffc107; }
.level-3 { background: rgba(255,107,107,0.15); color: var(--x-color); border: 1px solid var(--x-color); }

/* ── Board Grid ────────────────────────────────────────────────────────── */
.board {
  display: grid;
  grid-template-columns: repeat(3, var(--cell-size));
  grid-template-rows: repeat(3, var(--cell-size));
  gap: var(--gap);
  background: var(--grid);
  border-radius: 16px;
  padding: var(--gap);
  position: relative;
}

.cell {
  background: var(--bg);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  touch-action: manipulation;
  transition: background 0.15s ease;
  position: relative;
  overflow: hidden;
}

.cell:hover:not(.x):not(.o) {
  background: rgba(255, 255, 255, 0.04);
}

/* piece enter animation */
.piece {
  font-size: 2.6rem;
  font-weight: 900;
  line-height: 1;
  display: block;
  animation: pieceIn 0.22s cubic-bezier(0.175, 0.885, 0.32, 1.275) both;
}

@keyframes pieceIn {
  from { transform: scale(0) rotate(-25deg); opacity: 0; }
  to   { transform: scale(1) rotate(0deg);  opacity: 1; }
}

.cell.x .piece { color: var(--x-color); }
.cell.o .piece { color: var(--o-color); }

/* winning cell pulse */
.winning-cell.x { animation: winX 0.55s ease-in-out infinite alternate; }
.winning-cell.o { animation: winO 0.55s ease-in-out infinite alternate; }

@keyframes winX {
  from { background: rgba(255,107,107,0.08); }
  to   { background: rgba(255,107,107,0.32); box-shadow: inset 0 0 10px rgba(255,107,107,0.4); }
}
@keyframes winO {
  from { background: rgba(78,205,196,0.08); }
  to   { background: rgba(78,205,196,0.32); box-shadow: inset 0 0 10px rgba(78,205,196,0.4); }
}

/* ── Game-Over Overlay ─────────────────────────────────────────────────── */
.overlay {
  position: absolute;
  inset: 0;
  border-radius: 16px;
  background: rgba(15, 14, 23, 0.88);
  backdrop-filter: blur(6px);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity 0.3s ease;
  z-index: 10;
}

.overlay.show  { opacity: 1; }

.overlay-content {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.6rem;
  animation: overlayIn 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275) both;
}

@keyframes overlayIn {
  from { transform: scale(0.75); opacity: 0; }
  to   { transform: scale(1);    opacity: 1; }
}

.result-text {
  font-size: 1.9rem;
  font-weight: 900;
  background: linear-gradient(135deg, var(--x-color), var(--primary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.result-subtitle {
  font-size: 0.88rem;
  color: var(--text-dim);
  margin-bottom: 0.4rem;
  min-height: 1.2em;
}

.overlay-buttons {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  width: 148px;
}

/* ── Victory Screen ────────────────────────────────────────────────────── */
.victory-content {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

/* CSS star shape */
.victory-star {
  width: 70px;
  height: 70px;
  background: linear-gradient(135deg, #ffd700, #ff9800);
  clip-path: polygon(
    50% 0%, 61% 35%, 98% 35%, 68% 57%,
    79% 91%, 50% 70%, 21% 91%, 32% 57%,
    2% 35%,  39% 35%
  );
}

.victory-star.animate {
  animation: starIn 0.7s cubic-bezier(0.175, 0.885, 0.32, 1.275) both,
             starFloat 3s ease-in-out 0.7s infinite;
}

@keyframes starIn {
  from { transform: scale(0) rotate(-200deg); opacity: 0; }
  to   { transform: scale(1) rotate(0deg);    opacity: 1; }
}

@keyframes starFloat {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50%       { transform: translateY(-8px) rotate(5deg); }
}

.victory-title {
  font-size: clamp(2.5rem, 7vw, 3.5rem);
  font-weight: 900;
  background: linear-gradient(135deg, #ffd700, var(--x-color), var(--primary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: float 3s ease-in-out infinite;
}

.victory-sub {
  color: var(--text-dim);
  font-size: 0.95rem;
}

.victory-buttons {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  width: 180px;
  margin-top: 0.5rem;
}

/* ── Responsive ─────────────────────────────────────────────────────────── */
@media (max-width: 380px) {
  :root { --cell-size: 88px; }
  .piece { font-size: 2.2rem; }
}