:root {
  --bg: #f3f4f8;
  --card: #ffffff;
  --line: #d6d9e3;
  --text: #1d2433;
  --muted: #5d667a;
  --accent: #0f62fe;
  --danger: #c62828;
  --ok: #2e7d32;
  --cell-size: min(15vw, 74px);
  --gap: 8px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: radial-gradient(circle at top, #e9efff, var(--bg) 55%);
  color: var(--text);
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  display: grid;
  place-items: center;
  padding: 16px;
}

.home-link {
  position: fixed;
  top: 16px;
  left: 16px;
  z-index: 10;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--text);
  background: rgba(255, 255, 255, 0.94);
  font-weight: 800;
  text-decoration: none;
  box-shadow: 0 10px 24px rgba(17, 29, 58, 0.14);
}

.app {
  width: min(100%, 720px);
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 18px;
  box-shadow: 0 10px 34px rgba(17, 29, 58, 0.12);
}

.header h1 {
  margin: 0;
  font-size: clamp(1.4rem, 2.2vw, 2rem);
}

.header p {
  margin: 4px 0 0;
  color: var(--muted);
}

.score-panel {
  margin-top: 14px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.score-item {
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 12px;
  background: #f9fbff;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.score-label {
  color: var(--muted);
  font-weight: 800;
}

.score-item strong {
  font-size: 1.8rem;
  line-height: 1;
}

.score-x strong {
  color: #1858d0;
}

.score-o strong {
  color: #b43d2d;
}

.status-panel {
  margin-top: 14px;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 12px;
  background: #f9fbff;
}

.status-panel p {
  margin: 0;
}

.status-panel p + p {
  margin-top: 6px;
}

.action-panel,
.grid-move-panel,
.level-panel {
  margin-top: 12px;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 12px;
}

.panel-title {
  margin: 0 0 10px;
  font-weight: 700;
}

.action-options,
.level-options {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
}

.action-options label,
.level-options label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 600;
}

.setup-option {
  margin-top: 12px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  color: var(--text);
}

.action-menu-label {
  display: block;
  margin-bottom: 8px;
  font-weight: 700;
}

.action-menu {
  width: min(100%, 260px);
  min-height: 42px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  color: var(--text);
  padding: 0 12px;
  font: inherit;
  font-weight: 600;
}

.action-menu:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.direction-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  max-width: 220px;
}

.direction-grid button,
.footer-actions button {
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  color: var(--text);
  padding: 10px 12px;
  font: inherit;
  cursor: pointer;
}

.direction-grid button:disabled,
.footer-actions button:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.center-dot {
  cursor: default;
}

.board-wrap {
  margin-top: 14px;
  position: relative;
  width: fit-content;
}

.board {
  display: grid;
  grid-template-columns: repeat(5, var(--cell-size));
  gap: var(--gap);
}

.cell {
  width: var(--cell-size);
  height: var(--cell-size);
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #f8faff;
  color: var(--text);
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 700;
  cursor: pointer;
}

.cell:hover {
  background: #eef3ff;
}

.cell.in-grid {
  background: #ffffff;
}

.cell.cell-x {
  color: #1858d0;
}

.cell.cell-o {
  color: #b43d2d;
}

.cell.selected {
  outline: 3px solid var(--accent);
  outline-offset: -3px;
}

.grid-overlay {
  position: absolute;
  border: 4px solid var(--accent);
  border-radius: 12px;
  pointer-events: none;
  transition: all 180ms ease;
  box-shadow: 0 0 0 2px rgba(15, 98, 254, 0.15);
}

.message {
  margin: 12px 0 0;
  min-height: 24px;
  font-weight: 600;
}

.message.info {
  color: var(--muted);
}

.message.error {
  color: var(--danger);
}

.message.ok {
  color: var(--ok);
}

.footer-actions {
  margin-top: 8px;
  display: flex;
  gap: 8px;
}

.modal {
  position: fixed;
  inset: 0;
  background: rgba(8, 14, 28, 0.44);
  display: grid;
  place-items: center;
  padding: 16px;
}

.modal-card {
  width: min(100%, 380px);
  background: #fff;
  border-radius: 14px;
  padding: 18px;
  border: 1px solid var(--line);
}

.modal-card h2 {
  margin: 0;
}

.modal-card p {
  margin: 8px 0 14px;
  color: var(--muted);
}

.modal-card button {
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--accent);
  color: #fff;
  padding: 10px 14px;
  cursor: pointer;
}

.hidden {
  display: none !important;
}

@media (max-width: 560px) {
  :root {
    --cell-size: min(17vw, 62px);
    --gap: 6px;
  }

  .app {
    padding: 14px;
  }

  .score-panel {
    grid-template-columns: 1fr;
  }

  .direction-grid {
    max-width: 100%;
  }
}