:root {
  --bg: #0b1622;
  --panel: #12233a;
  --panel-2: #183050;
  --text: #e8f0fa;
  --muted: #8ea4bf;
  --water: #1d3f66;
  --water-hover: #2a5688;
  --ship: #8796a8;
  --hit: #ef4444;
  --miss: #cbd5e1;
  --sunk: #7f1d1d;
  --ok: #22c55e;
  --bad: #f43f5e;
  --accent: #38bdf8;
  --radius: 12px;
  --cell-gap: 3px;
}

* { box-sizing: border-box; }

html, body { margin: 0; }

html { background-color: var(--bg); }

body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg) radial-gradient(circle at top, #15304f 0%, var(--bg) 60%) no-repeat;
  color: var(--text);
  min-height: 100vh;
  -webkit-tap-highlight-color: transparent;
}

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 960px;
  margin: 0 auto;
  padding: 16px 16px 0;
}

.app-header h1 {
  margin: 0;
  font-size: clamp(1.4rem, 4vw, 2rem);
  letter-spacing: 0.04em;
}

main {
  max-width: 960px;
  margin: 0 auto;
  padding: 12px 16px 32px;
}

.status {
  background: var(--panel);
  border-radius: var(--radius);
  padding: 12px 16px;
  text-align: center;
  margin-bottom: 12px;
}

.turn {
  margin: 0;
  font-weight: 700;
  font-size: 1.15rem;
}

.turn.is-player { color: var(--accent); }
.turn.is-computer { color: #fbbf24; }
.turn.is-lose { color: var(--bad); }

.message {
  margin: 4px 0 0;
  color: var(--muted);
  min-height: 1.3em;
}

.btn {
  font: inherit;
  font-weight: 600;
  color: var(--text);
  background: var(--panel-2);
  border: 1px solid #2b4a70;
  border-radius: 999px;
  padding: 8px 16px;
  cursor: pointer;
  transition: background 0.15s, transform 0.05s;
}

.btn:hover:not(:disabled) { background: #22426b; }
.btn:active:not(:disabled) { transform: translateY(1px); }
.btn:disabled { opacity: 0.45; cursor: not-allowed; }
.btn:focus-visible, .cell:focus-visible, .ship-chip:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.btn-primary { background: var(--accent); color: #04263a; border-color: transparent; }
.btn-primary:hover:not(:disabled) { background: #7dd3fc; }
.btn-ghost { background: transparent; }

.placement-controls {
  background: var(--panel);
  border-radius: var(--radius);
  padding: 12px 16px;
  margin-bottom: 12px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.phase-battle .placement-controls,
.phase-over .placement-controls { display: none; }

.difficulty {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 10px;
}

.difficulty-label { color: var(--muted); font-weight: 600; }

.segmented {
  display: inline-flex;
  gap: 2px;
  padding: 3px;
  border: 1px solid #2b4a70;
  border-radius: 999px;
  background: var(--bg);
}

.segmented label { position: relative; }
.segmented input { position: absolute; inset: 0; margin: 0; opacity: 0; cursor: pointer; }
.segmented span {
  display: block;
  padding: 6px 16px;
  border-radius: 999px;
  font-weight: 600;
  color: var(--muted);
  transition: background 0.15s, color 0.15s;
}
.segmented label:hover input:not(:checked) + span { color: var(--text); }
.segmented input:checked + span { background: var(--accent); color: #04263a; }
.segmented input:focus-visible + span { outline: 2px solid var(--accent); outline-offset: 2px; }

.badge {
  margin-left: 6px;
  padding: 2px 8px;
  border-radius: 999px;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  vertical-align: middle;
  background: var(--panel-2);
}
.badge.is-easy { color: var(--ok); }
.badge.is-medium { color: var(--accent); }
.badge.is-hard { color: var(--bad); }

.ship-dock, .placement-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
}

.ship-chip {
  font: inherit;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border-radius: 999px;
  border: 1px solid #2b4a70;
  background: var(--panel-2);
  color: var(--text);
  cursor: pointer;
}

.ship-chip .pips { display: inline-flex; gap: 2px; }
.ship-chip .pips i { width: 8px; height: 8px; border-radius: 2px; background: var(--ship); }
.ship-chip.is-selected { border-color: var(--accent); box-shadow: 0 0 0 2px rgba(56, 189, 248, 0.35); }
.ship-chip.is-placed { opacity: 0.4; text-decoration: line-through; }

.boards {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  justify-content: center;
}

.board-wrap {
  background: var(--panel);
  border-radius: var(--radius);
  padding: 12px;
  width: min(100%, 440px);
}

.board-wrap h2 {
  margin: 0 0 8px;
  font-size: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  text-align: center;
}

.board {
  display: grid;
  grid-template-columns: repeat(11, 1fr);
  gap: var(--cell-gap);
  user-select: none;
  touch-action: manipulation;
}

.label {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: clamp(0.6rem, 2.4vw, 0.8rem);
  color: var(--muted);
  aspect-ratio: 1;
}

.cell {
  aspect-ratio: 1;
  min-width: 0;
  padding: 0;
  border: 0;
  border-radius: 4px;
  background: var(--water);
  position: relative;
  cursor: default;
  font: inherit;
}

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

.cell.miss::after,
.cell.hit::after {
  content: "";
  position: absolute;
  inset: 0;
  margin: auto;
  border-radius: 50%;
}

.cell.miss::after { width: 30%; height: 30%; background: var(--miss); }
.cell.hit { background: var(--hit); }
.cell.hit::after { width: 40%; height: 40%; background: #fff3; }
.cell.sunk { background: var(--sunk); }
.cell.sunk::after { content: "\2715"; color: #fecaca; display: flex; align-items: center; justify-content: center; font-size: clamp(0.6rem, 2.6vw, 1rem); background: none; width: auto; height: auto; }

.cell.just-shot { animation: pop 0.35s ease-out; }
@keyframes pop { from { transform: scale(0.6); } to { transform: scale(1); } }

/* Placement preview */
.phase-placement #player-board .cell { cursor: pointer; }
.cell.preview-ok { background: var(--ok); }
.cell.preview-bad { background: var(--bad); }

/* Enemy board is only interactive on the player's turn */
#enemy-board.is-active .cell:not(.hit):not(.miss) { cursor: crosshair; }
#enemy-board.is-active .cell:not(.hit):not(.miss):hover { background: var(--water-hover); }
#enemy-board:not(.is-active) { opacity: 0.85; }
.phase-placement #enemy-board { opacity: 0.35; }

.fleet {
  list-style: none;
  padding: 0;
  margin: 10px 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  justify-content: center;
  font-size: 0.85rem;
}

.fleet li {
  padding: 2px 10px;
  border-radius: 999px;
  background: var(--panel-2);
  color: var(--text);
}

.fleet li.is-sunk { background: var(--sunk); color: #fecaca; text-decoration: line-through; }

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
  margin-top: 16px;
  color: var(--muted);
  font-size: 0.85rem;
}

.legend span { display: inline-flex; align-items: center; gap: 6px; }
.swatch { width: 14px; height: 14px; border-radius: 3px; display: inline-block; }
.swatch-ship { background: var(--ship); }
.swatch-hit { background: var(--hit); }
.swatch-miss { background: var(--water); box-shadow: inset 0 0 0 4px var(--water), inset 0 0 0 7px var(--miss); }
.swatch-sunk { background: var(--sunk); }

.overlay {
  position: fixed;
  inset: 0;
  background: rgba(2, 8, 16, 0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  z-index: 10;
}

.overlay[hidden] { display: none; }

.modal {
  background: var(--panel);
  border-radius: var(--radius);
  padding: 28px 24px;
  text-align: center;
  max-width: 360px;
  width: 100%;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

.modal h2 { margin: 0 0 8px; font-size: 1.8rem; }
.modal.is-win h2 { color: var(--ok); }
.modal.is-lose h2 { color: var(--bad); }
.modal p { color: var(--muted); margin: 0 0 20px; }

/* On narrow screens show the enemy board first during battle, since that is where you tap */
@media (max-width: 920px) {
  .phase-battle #enemy-wrap { order: -1; }
}

@media (max-width: 480px) {
  :root { --cell-gap: 2px; }
  main { padding: 8px 10px 24px; }
  .board-wrap { padding: 8px; }
  .btn { padding: 8px 12px; font-size: 0.9rem; }
}

@media (prefers-reduced-motion: reduce) {
  .cell.just-shot { animation: none; }
}