:root {
  --bg: #f5efe2;
  --bg-accent: #e4d8bd;
  --ink: #13243a;
  --ink-soft: #4b617a;
  --card: rgba(255, 250, 242, 0.82);
  --line: rgba(19, 36, 58, 0.14);
  --blue: #1f78b4;
  --red: #d8524a;
  --shadow: 0 30px 80px rgba(19, 36, 58, 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 top left, rgba(31, 120, 180, 0.16), transparent 28%),
    radial-gradient(circle at bottom right, rgba(216, 82, 74, 0.16), transparent 26%),
    linear-gradient(135deg, var(--bg), var(--bg-accent));
}

.page-shell {
  width: min(1100px, calc(100vw - 32px));
  margin: 0 auto;
  padding: 32px 0 48px;
}

.hero {
  padding: 12px 4px 28px;
  animation: fade-in 0.65s ease;
}

.eyebrow {
  margin: 0 0 10px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.8rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

.hero h1 {
  margin: 0;
  font-size: clamp(2.3rem, 5vw, 4.4rem);
  line-height: 0.94;
}

.hero-copy {
  max-width: 700px;
  margin: 16px 0 0;
  font-size: 1.05rem;
  line-height: 1.6;
  color: var(--ink-soft);
}

.layout {
  display: grid;
  gap: 24px;
  grid-template-columns: 360px 1fr;
}

.panel {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 28px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(12px);
}

.controls {
  padding: 24px;
  animation: fade-up 0.8s ease;
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.panel-header h2 {
  margin: 0;
  font-size: 1.2rem;
}

.badge {
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(31, 120, 180, 0.12);
  color: var(--blue);
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.75rem;
}

.control-group {
  display: grid;
  gap: 10px;
  margin-top: 20px;
}

.control-group span,
.score-label {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--ink-soft);
}

select,
.action-button {
  border: 1px solid rgba(19, 36, 58, 0.12);
  border-radius: 18px;
  font: inherit;
}

select {
  width: 100%;
  padding: 14px 16px;
  background: rgba(255, 255, 255, 0.7);
}

.button-row {
  display: grid;
  gap: 12px;
  margin-top: 20px;
}

.action-button {
  padding: 14px 16px;
  font-weight: 600;
  color: white;
  background: linear-gradient(135deg, var(--ink), #38506b);
  cursor: pointer;
  transition: transform 0.18s ease, box-shadow 0.18s ease;
  box-shadow: 0 16px 30px rgba(19, 36, 58, 0.16);
}

.action-button.muted {
  background: linear-gradient(135deg, #a03e39, #d8524a);
}

.action-button:hover {
  transform: translateY(-1px);
}

.score-card {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin-top: 20px;
  padding: 16px;
  border-radius: 22px;
  background: rgba(255, 255, 255, 0.56);
}

.score-card strong {
  display: block;
  margin-top: 10px;
  font-size: 2rem;
}

.status {
  margin-top: 20px;
  padding: 16px;
  border-radius: 18px;
  background: rgba(19, 36, 58, 0.06);
  color: var(--ink);
}

.note {
  margin: 16px 0 0;
  color: var(--ink-soft);
  line-height: 1.55;
}

.board-panel {
  display: grid;
  place-items: center;
  padding: 28px;
  animation: fade-up 0.95s ease;
}

.board {
  display: grid;
  grid-template-columns: repeat(3, minmax(84px, 1fr));
  gap: 14px;
  width: min(520px, 100%);
}

.cell {
  aspect-ratio: 1 / 1;
  border: none;
  border-radius: 22px;
  background: rgba(255, 255, 255, 0.92);
  box-shadow: inset 0 0 0 1px rgba(19, 36, 58, 0.08);
  font-family: "Space Grotesk", sans-serif;
  font-size: clamp(2.4rem, 8vw, 4.5rem);
  font-weight: 700;
  color: var(--ink);
  cursor: pointer;
  transition: transform 0.16s ease, background 0.16s ease, box-shadow 0.16s ease;
}

.cell:hover:not(:disabled) {
  transform: translateY(-2px);
  background: rgba(255, 255, 255, 1);
  box-shadow: 0 16px 28px rgba(19, 36, 58, 0.12);
}

.cell:disabled {
  cursor: default;
}

.cell.human {
  color: var(--red);
}

.cell.ai {
  color: var(--blue);
}

@keyframes fade-in {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fade-up {
  from {
    opacity: 0;
    transform: translateY(18px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 880px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .board {
    width: 100%;
  }
}