:root {
  --mvbs-bg: #0a0e17;
  --mvbs-panel: #131a29;
  --mvbs-panel-border: #23304a;
  --mvbs-text: #e7ecf7;
  --mvbs-muted: #8b97b3;
  --mvbs-accent: #37e0ff;
  --mvbs-accent-2: #a78bfa;
  --mvbs-success: #34d399;
  --mvbs-warn: #fbbf24;
  --mvbs-danger: #f87171;
  --mvbs-cell: #0f1522;
  --mvbs-cell-border: #1f2b42;
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  min-height: 100%;
  background: radial-gradient(ellipse at top, #101a2e 0%, var(--mvbs-bg) 60%);
  color: var(--mvbs-text);
}

#app {
  max-width: 1100px;
  margin: 0 auto;
  padding: 16px;
  padding-bottom: 64px;
}

h1, h2, h3 { margin: 0 0 8px; }
.mvbs-accent { color: var(--mvbs-accent); }

.mvbs-panel {
  background: var(--mvbs-panel);
  border: 1px solid var(--mvbs-panel-border);
  border-radius: 14px;
  padding: 16px;
  margin-bottom: 16px;
}

.mvbs-hint { color: var(--mvbs-muted); font-size: 0.85rem; margin: 4px 0; }
.mvbs-row { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; margin: 8px 0; }

.mvbs-input {
  background: var(--mvbs-cell);
  border: 1px solid var(--mvbs-cell-border);
  color: var(--mvbs-text);
  border-radius: 8px;
  padding: 8px 10px;
  font-size: 1rem;
}
.mvbs-input-code { text-transform: uppercase; letter-spacing: 2px; width: 120px; }
.mvbs-input-num { width: 80px; }

.mvbs-btn {
  background: #1c2740;
  border: 1px solid var(--mvbs-panel-border);
  color: var(--mvbs-text);
  padding: 9px 16px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.95rem;
}
.mvbs-btn:hover:not(:disabled) { background: #263455; }
.mvbs-btn:disabled { opacity: 0.4; cursor: not-allowed; }
.mvbs-btn-primary {
  background: linear-gradient(135deg, var(--mvbs-accent), var(--mvbs-accent-2));
  color: #071018;
  border: none;
  font-weight: 700;
}
.mvbs-btn-primary:hover:not(:disabled) { filter: brightness(1.1); }
.mvbs-btn-small { padding: 5px 10px; font-size: 0.82rem; }
.mvbs-btn-tiny { padding: 2px 8px; font-size: 0.75rem; }
.mvbs-btn-wide { width: 100%; margin-top: 8px; }

/* Home */
.mvbs-hero { text-align: center; padding: 24px 0 8px; }
.mvbs-hero h1 { font-size: 2rem; letter-spacing: 1px; }
.mvbs-tagline { color: var(--mvbs-muted); }
.mvbs-name-label { display: block; margin: 12px 0; }
.mvbs-name-label .mvbs-input { display: block; width: 100%; margin-top: 4px; }
.mvbs-advanced { margin: 12px 0; color: var(--mvbs-muted); }
.mvbs-advanced-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 10px; margin-top: 8px; }
.mvbs-advanced-grid label { display: flex; flex-direction: column; gap: 4px; font-size: 0.82rem; }
.mvbs-rules ul { margin: 8px 0 0; padding-left: 20px; color: var(--mvbs-muted); font-size: 0.9rem; }
.mvbs-rules li { margin-bottom: 4px; }

/* Grid */
.mvbs-grid {
  display: inline-block;
  border-radius: 10px;
  overflow: hidden;
  background: var(--mvbs-cell-border);
  gap: 1px;
  padding: 1px;
}
.mvbs-grid-header, .mvbs-grid-row { display: grid; grid-template-columns: 22px repeat(var(--board-size), minmax(24px, 1fr)); gap: 1px; }
.mvbs-grid-corner, .mvbs-grid-colhead, .mvbs-grid-rowhead {
  display: flex; align-items: center; justify-content: center;
  font-size: 0.7rem; color: var(--mvbs-muted); background: var(--mvbs-panel);
}
.mvbs-cell {
  aspect-ratio: 1;
  min-width: 24px;
  background: var(--mvbs-cell);
  border: none;
  color: var(--mvbs-text);
  display: flex; align-items: center; justify-content: center;
  font-size: 0.85rem;
  cursor: pointer;
}
.mvbs-cell:hover:not(:disabled) { background: #1a2438; }
.mvbs-cell:disabled { cursor: default; }
.mvbs-cell-ship { background: #1c3a5e; }
.mvbs-cell-command { background: #2c1c5e; color: #d9c9ff; }
.mvbs-cell-damaged { background: #5e1c1c !important; color: #ffd9d9; }
.mvbs-cell-miss { background: #0f1522; color: var(--mvbs-muted); }
.mvbs-cell-hit { background: #5e2c1c; color: #ffcf9e; }
.mvbs-cell-command-hit { background: #7a1c3a; color: #ffd0e0; }

/* Placement */
.mvbs-placement { display: grid; grid-template-columns: 1fr 320px; gap: 16px; }
.mvbs-board-wrap { grid-column: 1; }
.mvbs-ship-list { list-style: none; padding: 0; margin: 8px 0; }
.mvbs-ship-list li { display: flex; justify-content: space-between; align-items: center; padding: 4px 0; border-bottom: 1px solid var(--mvbs-panel-border); font-size: 0.85rem; }
.mvbs-errors { color: var(--mvbs-danger); font-size: 0.82rem; padding-left: 18px; }
.mvbs-checkbox-label { display: flex; align-items: center; gap: 4px; font-size: 0.85rem; }
.mvbs-player-list { list-style: none; padding: 0; }
.mvbs-player-list li { display: flex; justify-content: space-between; padding: 6px 0; border-bottom: 1px solid var(--mvbs-panel-border); }
.mvbs-ready { color: var(--mvbs-success); }
.mvbs-not-ready { color: var(--mvbs-muted); }

/* Battle */
.mvbs-battle-header { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; margin-bottom: 12px; }
.mvbs-room-tag { color: var(--mvbs-muted); font-size: 0.8rem; letter-spacing: 1px; }
.mvbs-cmd-hp { font-size: 1rem; }
.mvbs-desync { min-width: 220px; }
.mvbs-desync-label { font-size: 0.78rem; color: var(--mvbs-muted); margin-bottom: 3px; }
.mvbs-desync-track { height: 8px; background: var(--mvbs-cell); border-radius: 4px; overflow: hidden; }
.mvbs-desync-fill { height: 100%; background: var(--mvbs-accent); transition: width 0.2s; }
.mvbs-desync-fill.mvbs-desync-full { background: var(--mvbs-danger); }

.mvbs-battle-columns { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.mvbs-universe-tabs { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 10px; }
.mvbs-tab { background: var(--mvbs-cell); border: 1px solid var(--mvbs-cell-border); color: var(--mvbs-text); padding: 6px 12px; border-radius: 999px; cursor: pointer; font-size: 0.82rem; }
.mvbs-tab-active { border-color: var(--mvbs-accent); color: var(--mvbs-accent); }
.mvbs-tab-dead { opacity: 0.45; text-decoration: line-through; }

.mvbs-banner { margin-top: 14px; padding: 12px; border-radius: 10px; text-align: center; font-weight: 600; }
.mvbs-banner-danger { background: rgba(248, 113, 113, 0.15); color: var(--mvbs-danger); border: 1px solid rgba(248,113,113,0.4); }

.mvbs-warp-flash { animation: mvbs-warp 0.9s ease-out; }
@keyframes mvbs-warp {
  0% { box-shadow: 0 0 0 0 rgba(167,139,250,0.9); }
  100% { box-shadow: 0 0 0 30px rgba(167,139,250,0); }
}

/* Game over */
.mvbs-gameover { text-align: center; padding: 60px 0; }
.mvbs-gameover h1 { font-size: 3rem; letter-spacing: 3px; }

/* Toasts */
.mvbs-toast-host { position: fixed; top: 12px; right: 12px; z-index: 999; display: flex; flex-direction: column; gap: 8px; max-width: 320px; }
.mvbs-toast {
  background: var(--mvbs-panel); border: 1px solid var(--mvbs-panel-border);
  color: var(--mvbs-text); padding: 10px 14px; border-radius: 8px;
  font-size: 0.85rem; opacity: 0; transform: translateY(-8px); transition: all 0.25s;
  box-shadow: 0 4px 16px rgba(0,0,0,0.4);
}
.mvbs-toast-in { opacity: 1; transform: translateY(0); }
.mvbs-toast-success { border-color: var(--mvbs-success); }
.mvbs-toast-warn { border-color: var(--mvbs-warn); }
.mvbs-toast-error { border-color: var(--mvbs-danger); }

@media (max-width: 780px) {
  .mvbs-placement, .mvbs-battle-columns { grid-template-columns: 1fr; }
}