/* ── Reset & Base ────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:        #09141f;
  --surface:   #112233;
  --surface2:  #1a3344;
  --border:    #1e3d55;
  --accent:    #1e90ff;
  --accent2:   #0066cc;
  --gold:      #e8a020;
  --red:       #e03030;
  --red-dark:  #8b0000;
  --miss:      #2a4a5a;
  --ship:      #1565c0;
  --ship-sunk: #555;
  --text:      #d8e8f0;
  --text-dim:  #5a7a8a;
  --cell:      42px;
  --gap:       2px;
  --radius:    3px;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ── Screens ─────────────────────────────────────────── */
.screen {
  display: none;
  width: 100%;
  min-height: 100vh;
  align-items: center;
  justify-content: center;
  padding: 24px;
}
.screen.active { display: flex; }

/* ── Card ────────────────────────────────────────────── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 52px 48px;
  text-align: center;
  max-width: 480px;
  width: 100%;
  box-shadow: 0 12px 48px rgba(0,0,0,.5);
}

.logo {
  font-size: 3rem;
  margin-bottom: 16px;
  filter: drop-shadow(0 0 20px rgba(30,144,255,.4));
}

h1 {
  font-size: 2.4rem;
  font-weight: 800;
  letter-spacing: 6px;
  color: var(--gold);
  text-shadow: 0 0 30px rgba(232,160,32,.4);
  margin-bottom: 10px;
}

h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 12px;
}

.subtitle, p {
  color: var(--text-dim);
  margin-bottom: 28px;
  line-height: 1.5;
}

.dim { color: var(--text-dim); font-size: .85rem; }

/* ── Buttons ─────────────────────────────────────────── */
.btn-primary {
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 12px 28px;
  border-radius: 10px;
  font-size: .95rem;
  font-weight: 700;
  cursor: pointer;
  transition: background .2s, transform .1s, box-shadow .2s;
  letter-spacing: .5px;
}
.btn-primary:hover:not(:disabled) {
  background: var(--accent2);
  box-shadow: 0 4px 20px rgba(30,144,255,.4);
  transform: translateY(-1px);
}
.btn-primary:active { transform: translateY(0); }
.btn-primary:disabled {
  background: var(--surface2);
  color: var(--text-dim);
  cursor: default;
  box-shadow: none;
}
.btn-primary.btn-lg { padding: 15px 40px; font-size: 1.05rem; width: 100%; margin-top: 8px; }

.btn-secondary {
  background: var(--surface2);
  color: var(--text);
  border: 1px solid var(--border);
  padding: 9px 18px;
  border-radius: 8px;
  font-size: .85rem;
  cursor: pointer;
  transition: background .15s, border-color .15s;
}
.btn-secondary:hover { background: #203f55; border-color: var(--accent); }

/* ── Spinner ─────────────────────────────────────────── */
.spinner {
  width: 44px; height: 44px;
  border: 3px solid var(--surface2);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin .8s linear infinite;
  margin: 0 auto;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Link Box ────────────────────────────────────────── */
.link-box {
  display: flex;
  gap: 8px;
  margin-bottom: 8px;
}
.link-box input {
  flex: 1;
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 10px 14px;
  border-radius: 8px;
  font-size: .85rem;
  outline: none;
}
kbd {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 7px;
  font-size: .8rem;
  font-family: monospace;
}

/* ── Board Labels ────────────────────────────────────── */
.board-wrap { display: inline-block; }

.col-labels {
  display: grid;
  grid-template-columns: 22px repeat(10, var(--cell));
  gap: var(--gap);
  margin-bottom: var(--gap);
}
.col-labels span {
  text-align: center;
  font-size: .7rem;
  color: var(--text-dim);
  line-height: var(--cell);
}

.board-rows { display: flex; gap: var(--gap); }

.row-labels {
  display: grid;
  grid-template-rows: repeat(10, var(--cell));
  gap: var(--gap);
  width: 22px;
}
.row-labels span {
  font-size: .7rem;
  color: var(--text-dim);
  text-align: right;
  line-height: var(--cell);
  padding-right: 4px;
}

/* ── Board Grid ──────────────────────────────────────── */
.board {
  display: grid;
  grid-template-columns: repeat(10, var(--cell));
  grid-template-rows: repeat(10, var(--cell));
  gap: var(--gap);
  background: #0a1e2e;
  padding: var(--gap);
  border-radius: 6px;
  border: 1px solid var(--border);
}

/* ── Cells ───────────────────────────────────────────── */
.cell {
  width: var(--cell);
  height: var(--cell);
  background: #0d2035;
  border-radius: var(--radius);
  position: relative;
  transition: background .12s;
  display: flex;
  align-items: center;
  justify-content: center;
}

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

.cell.hit {
  background: var(--red);
  animation: hit-flash .4s ease;
}
.cell.miss { background: var(--miss); }
.cell.sunk { background: var(--red-dark); }

@keyframes hit-flash {
  0%   { background: #fff; }
  30%  { background: #ff8800; }
  100% { background: var(--red); }
}

/* Symbols */
.cell.hit::after {
  content: '✕';
  color: rgba(255,255,255,.85);
  font-size: 1.1rem;
  font-weight: 700;
}
.cell.miss::after {
  content: '●';
  color: rgba(255,255,255,.25);
  font-size: .55rem;
}
.cell.sunk::after {
  content: '✕';
  color: rgba(255,100,100,.9);
  font-size: 1.1rem;
  font-weight: 700;
}

/* Placement preview */
.cell.preview-ok { background: rgba(30,144,255,.45); }
.cell.preview-bad { background: rgba(220,40,40,.45); }

/* Enemy board clickable */
.board-enemy .cell.empty {
  cursor: crosshair;
}
.board-enemy .cell.empty:hover {
  background: rgba(30,144,255,.2);
  box-shadow: 0 0 0 2px var(--accent) inset;
}

/* ── Placement Screen ────────────────────────────────── */
.placement-layout {
  display: flex;
  gap: 48px;
  align-items: flex-start;
  padding: 32px;
  min-height: 100vh;
  align-items: center;
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
}

.sidebar {
  flex: 0 0 240px;
}
.sidebar h2 {
  font-size: 1.4rem;
  color: var(--gold);
  margin-bottom: 8px;
}
.hint {
  font-size: .8rem;
  color: var(--text-dim);
  margin-bottom: 20px;
  line-height: 1.5;
}

/* Ship list */
#ship-list { display: flex; flex-direction: column; gap: 6px; margin-bottom: 16px; }

.ship-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 14px;
  cursor: pointer;
  transition: border-color .15s, background .15s, opacity .15s;
  user-select: none;
}
.ship-item:hover:not(.placed) {
  border-color: var(--accent);
  background: var(--surface2);
}
.ship-item.selected {
  border-color: var(--accent);
  background: #132d4a;
  box-shadow: 0 0 0 2px var(--accent);
}
.ship-item.placed {
  opacity: .35;
  cursor: default;
}
.ship-name {
  font-size: .75rem;
  font-weight: 700;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 5px;
}
.ship-bar-wrap { display: flex; gap: 3px; }
.ship-seg {
  width: 18px;
  height: 12px;
  background: var(--ship);
  border-radius: 2px;
  transition: background .15s;
}
.ship-item.placed .ship-seg { background: #2a4a62; }

.sidebar-actions {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 12px;
}

.placement-status {
  margin-top: 12px;
  font-size: .82rem;
  color: var(--text-dim);
  text-align: center;
  min-height: 20px;
}

.board-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}
.board-title {
  font-size: .75rem;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--text-dim);
}

/* ── Battle Screen ───────────────────────────────────── */
.battle-layout {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
  padding: 24px;
  min-height: 100vh;
  justify-content: center;
  width: 100%;
}

.battle-header {
  display: flex;
  align-items: center;
  gap: 32px;
  flex-wrap: wrap;
  justify-content: center;
}
.game-title {
  font-size: 1.4rem;
  letter-spacing: 4px;
  color: var(--gold);
  text-shadow: none;
}

.turn-banner {
  padding: 10px 28px;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 700;
  border: 1px solid var(--border);
  transition: all .3s;
}
.turn-banner.my-turn {
  background: rgba(30,144,255,.15);
  border-color: var(--accent);
  color: var(--accent);
  animation: pulse-blue 2s ease-in-out infinite;
}
.turn-banner.their-turn {
  background: rgba(90,122,138,.1);
  color: var(--text-dim);
}
@keyframes pulse-blue {
  0%, 100% { box-shadow: 0 0 0 0 rgba(30,144,255,.3); }
  50%       { box-shadow: 0 0 0 8px rgba(30,144,255,0); }
}

.boards-row {
  display: flex;
  gap: 52px;
  flex-wrap: wrap;
  justify-content: center;
}

.board-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

.fleet-status {
  font-size: .78rem;
  color: var(--text-dim);
  text-align: center;
  height: 18px;
}

/* ── Toast ───────────────────────────────────────────── */
.toast {
  position: fixed;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 12px 28px;
  border-radius: 10px;
  font-size: .9rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity .25s, transform .25s;
  z-index: 50;
  white-space: nowrap;
}
.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}
.toast.hit-toast { border-color: var(--red); color: #ff9090; }
.toast.sunk-toast { border-color: var(--gold); color: var(--gold); }
.toast.miss-toast { border-color: var(--miss); }

/* ── Overlay ─────────────────────────────────────────── */
.overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.75);
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 24px;
}
.overlay.show { display: flex; }

/* ── Responsive ──────────────────────────────────────── */
@media (max-width: 860px) {
  :root { --cell: 32px; }
  .placement-layout { flex-direction: column; align-items: center; padding: 20px; }
  .sidebar { flex: unset; width: 100%; max-width: 440px; }
  .boards-row { gap: 24px; }
  .battle-header { gap: 12px; }
}

@media (max-width: 520px) {
  :root { --cell: 28px; }
  .col-labels { grid-template-columns: 18px repeat(10, var(--cell)); }
  .row-labels { width: 18px; }
  h1 { font-size: 1.8rem; }
}