:root {
  --bg-start: #f4f7fb;
  --bg-end: #d9e4f5;
  --panel: rgba(255, 255, 255, 0.88);
  --ink: #0f172a;
  --muted: #475569;
  --brand: #0f766e;
  --brand-strong: #115e59;
  --accent: #ea580c;
  --line: #cbd5e1;
  --board-cell: #ffffff;
  --board-hover: #f0fdfa;
  --win: #16a34a;
  --shadow: 0 20px 40px rgba(15, 23, 42, 0.12);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: 'Space Grotesk', sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at 10% 20%, rgba(15, 118, 110, 0.15), transparent 30%),
    radial-gradient(circle at 90% 0%, rgba(234, 88, 12, 0.14), transparent 28%),
    linear-gradient(140deg, var(--bg-start), var(--bg-end));
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
}

.app-shell {
  width: min(920px, 100%);
}

.app-header {
  text-align: center;
  margin-bottom: 18px;
}

.app-header h1 {
  margin: 0;
  letter-spacing: 0.02em;
  font-size: clamp(2rem, 4vw, 2.8rem);
}

.subtitle {
  margin: 8px 0 0;
  color: var(--muted);
}

.panel {
  background: var(--panel);
  border: 1px solid rgba(255, 255, 255, 0.9);
  border-radius: 18px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(8px);
  padding: 18px;
}

.menu-panel,
.waiting-panel,
.game-panel {
  animation: fade-up 220ms ease-out;
}

@keyframes fade-up {
  from {
    transform: translateY(8px);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

.menu-panel {
  width: min(560px, 100%);
  margin: 0 auto;
}

.menu-panel h2,
.waiting-panel h2 {
  margin-top: 0;
}

label {
  display: block;
  margin-bottom: 6px;
  font-weight: 500;
}

input[type='text'] {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 12px;
  font-size: 1rem;
  padding: 11px 12px;
  font-family: inherit;
  color: var(--ink);
  outline: none;
  transition: border-color 120ms ease, box-shadow 120ms ease;
}

input[type='text']:focus {
  border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(15, 118, 110, 0.18);
}

.menu-actions {
  margin-top: 14px;
}

.join-hint {
  margin-top: 14px;
  padding: 12px;
  border: 1px dashed var(--line);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.6);
}

.join-hint p {
  margin: 0 0 8px;
  color: var(--muted);
}

.waiting-panel {
  width: min(560px, 100%);
  margin: 16px auto 0;
}

.share-row {
  display: flex;
  gap: 10px;
}

.hint {
  color: var(--muted);
  margin-bottom: 0;
}

.btn {
  border: 0;
  border-radius: 11px;
  padding: 10px 14px;
  font-size: 0.95rem;
  font-family: inherit;
  font-weight: 600;
  cursor: pointer;
  transition: transform 100ms ease, filter 120ms ease;
}

.btn:hover {
  filter: brightness(1.04);
}

.btn:active {
  transform: translateY(1px);
}

.btn-primary {
  background: var(--brand);
  color: #fff;
}

.btn-secondary {
  background: #fff;
  border: 1px solid var(--line);
  color: var(--ink);
}

.game-panel {
  margin-top: 16px;
  width: min(640px, 100%);
  margin-left: auto;
  margin-right: auto;
}

.player-strip {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 10px;
}

.player-card {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fff;
  padding: 10px;
  min-width: 0;
}

.player-title {
  color: var(--muted);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.player-name {
  font-weight: 700;
  margin-top: 3px;
}

.player-score {
  margin-top: 7px;
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--accent);
}

.versus {
  color: var(--muted);
  font-weight: 700;
}

.status {
  text-align: center;
  font-weight: 500;
  margin: 16px 0;
}

.board {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}

.cell {
  aspect-ratio: 1;
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  background: var(--board-cell);
  color: var(--ink);
  font-family: inherit;
  font-size: clamp(2rem, 8vw, 3rem);
  font-weight: 700;
  cursor: pointer;
  transition: transform 100ms ease, background 120ms ease;
}

.cell:hover {
  background: var(--board-hover);
}

.cell:active {
  transform: translateY(1px);
}

.cell.x {
  color: var(--brand-strong);
}

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

.cell.disabled {
  cursor: not-allowed;
}

.cell.winner {
  background: rgba(22, 163, 74, 0.15);
  border-color: var(--win);
}

.controls {
  margin-top: 14px;
  display: flex;
  justify-content: center;
}

.error-text {
  color: #b91c1c;
  min-height: 1.2em;
  margin-bottom: 0;
}

.hidden {
  display: none;
}

@media (max-width: 640px) {
  body {
    padding: 14px;
  }

  .panel {
    padding: 14px;
    border-radius: 14px;
  }

  .share-row {
    flex-direction: column;
  }

  .player-strip {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 8px;
  }

  .versus {
    display: none;
  }

  .player-card {
    padding: 8px;
  }

  .player-title {
    font-size: 0.7rem;
  }

  .player-name {
    font-size: 0.9rem;
    margin-top: 2px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  .player-score {
    margin-top: 5px;
    font-size: 1.1rem;
  }
}