:root {
  --cell-size: 32px;
  --sea: #0b3d91;
  --ship: #445566;
  --hit: #d64545;
  --miss: #cfd8dc;
  --sunk: #7a1f1f;
}

* {
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', Arial, sans-serif;
  background: #eef3f8;
  margin: 0;
  padding: 24px;
  text-align: center;
  color: #1b1f24;
}

.app-header h1 {
  margin-bottom: 4px;
}

.game-status {
  font-weight: 600;
  min-height: 1.2em;
}

.boards-wrapper {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 40px;
  margin-top: 24px;
}

.board-section h2 {
  font-size: 1rem;
  margin-bottom: 8px;
}

.board {
  display: grid;
  grid-template-columns: repeat(var(--board-size, 10), var(--cell-size));
  grid-template-rows: repeat(var(--board-size, 10), var(--cell-size));
  gap: 2px;
  background: #14213d;
  padding: 4px;
  border-radius: 6px;
}

.board--disabled {
  pointer-events: none;
  opacity: 0.75;
}

.cell {
  width: var(--cell-size);
  height: var(--cell-size);
  background: var(--sea);
  border: none;
  cursor: pointer;
  transition: background 0.15s ease;
}

.cell--ship {
  background: var(--ship);
}

.cell--hit {
  background: var(--hit);
}

.cell--sunk {
  background: var(--sunk);
}

.cell--miss {
  background: var(--miss);
  cursor: default;
}

.controls {
  margin-top: 24px;
}

#new-game-btn {
  padding: 10px 20px;
  font-size: 1rem;
  border: none;
  border-radius: 6px;
  background: #14213d;
  color: #fff;
  cursor: pointer;
}

#new-game-btn:hover {
  background: #1f2f57;
}