*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:      #0d0d1a;
  --surface: #13132a;
  --panel:   #1a1a35;
  --border:  #2a2a55;
  --accent:  #5c6bc0;
  --accent2: #7986cb;
  --text:    #e8e8f4;
  --muted:   #6868a0;
  --red:     #e63946;
  --blue:    #4895ef;
  --green:   #2ec4b6;
  --yellow:  #ffd166;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, 'Segoe UI', sans-serif;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
}

/* ── Header ── */
header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 10px 16px;
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  flex-shrink: 0;
}

h1 {
  font-size: 1.25rem;
  font-weight: 900;
  letter-spacing: 3px;
  text-transform: uppercase;
  background: linear-gradient(135deg, var(--yellow) 0%, var(--red) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  flex-shrink: 0;
  user-select: none;
}

nav {
  display: flex;
  gap: 4px;
  flex-wrap: nowrap;
  overflow-x: auto;
  overflow-y: hidden;
  scrollbar-width: none;
  -ms-overflow-style: none;
  margin-left: auto;
  padding-bottom: 2px; /* prevent clipping */
}
nav::-webkit-scrollbar { display: none; }

.mode-btn {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
  padding: 5px 12px;
  border-radius: 20px;
  cursor: pointer;
  font-size: 0.8rem;
  font-weight: 600;
  transition: color 0.15s, border-color 0.15s, background 0.15s;
  white-space: nowrap;
}
.mode-btn:hover { color: var(--text); border-color: var(--accent2); }
.mode-btn.active { background: var(--accent); color: #fff; border-color: var(--accent); }

#player-info {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.78rem;
  color: var(--muted);
  flex-shrink: 0;
}

#btn-set-username {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 3px 8px;
  border-radius: 4px;
  cursor: pointer;
  font-size: 0.8rem;
  transition: color 0.15s, border-color 0.15s;
}
#btn-set-username:hover { color: var(--text); border-color: var(--accent2); }

#bmc-header {
  font-size: 0.72rem;
  color: var(--muted);
  text-decoration: none;
  white-space: nowrap;
  flex-shrink: 0;
  transition: color 0.15s;
}
#bmc-header:hover { color: var(--yellow); }

/* ── Main layout ── */
main {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 16px;
  gap: 24px;
  min-height: 0;
  overflow-y: auto;
}

/* ── Game area ── */
#game-area {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  position: relative;
  flex-shrink: 0;
}

/* ── Board ── */
#board-wrap {
  /* fill viewport: limited by width, by remaining height after chrome, capped at 900px */
  width: min(calc(100vw - 32px), calc(100dvh - 250px), 900px);
  aspect-ratio: 1;
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 0 0 0 2px var(--border), 0 12px 40px rgba(0,0,0,0.6);
  flex-shrink: 0;
}

canvas#board {
  width: 100%;
  height: 100%;
  display: block;
  image-rendering: pixelated;
}

/* ── Stats ── */
#stats {
  display: flex;
  gap: 18px;
  font-size: 0.85rem;
  color: var(--muted);
  align-items: center;
  flex-wrap: wrap;
  justify-content: center;
}
#stats strong { color: var(--yellow); font-size: 0.95rem; }
#seed-display { font-size: 0.78rem; color: var(--muted); }

/* ── Controls ── */
#controls {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
}
.control-row { display: flex; gap: 3px; }

#controls button {
  width: 46px;
  height: 46px;
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--text);
  font-size: 1rem;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.12s, transform 0.08s;
  display: flex;
  align-items: center;
  justify-content: center;
}
#controls button:hover  { background: var(--accent); border-color: var(--accent); }
#controls button:active { transform: scale(0.9); }
#btn-cw, #btn-ccw { font-size: 1.3rem; color: var(--yellow); }

/* ── Mode controls ── */
#mode-controls {
  display: flex;
  gap: 8px;
  align-items: center;
}

#btn-new-game {
  padding: 7px 18px;
  background: var(--accent);
  border: none;
  color: #fff;
  border-radius: 6px;
  cursor: pointer;
  font-weight: 600;
  font-size: 0.85rem;
  transition: background 0.15s;
}
#btn-new-game:hover { background: var(--accent2); }

#seed-input {
  padding: 6px 10px;
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 6px;
  width: 140px;
  font-size: 0.85rem;
}
#seed-input:focus { outline: none; border-color: var(--accent2); }

/* ── Replay controls ── */
#replay-controls {
  display: none;
  align-items: center;
  gap: 10px;
  font-size: 0.85rem;
  color: var(--muted);
}

#btn-stop-replay {
  padding: 5px 12px;
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.15s;
}
#btn-stop-replay:hover { background: var(--accent); border-color: var(--accent); }

/* ── Multiplayer overlay ── */
#mp-overlay {
  display: none;
  position: absolute;
  inset: 0;
  background: rgba(5, 5, 20, 0.9);
  backdrop-filter: blur(6px);
  z-index: 10;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 14px;
  border-radius: 10px;
}

#mp-status {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
  text-align: center;
  padding: 0 16px;
}

#mp-players {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: center;
  font-size: 0.88rem;
  padding: 0 16px;
}

#btn-mp-ready {
  display: none;
  font-size: 1rem;
  padding: 10px 36px;
  background: var(--green);
  border: none;
  color: #fff;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 700;
  transition: filter 0.15s;
}
#btn-mp-ready:hover { filter: brightness(1.12); }
#btn-mp-ready:disabled { opacity: 0.6; cursor: default; filter: none; }

#btn-mp-leave {
  font-size: 0.82rem;
  background: transparent;
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 6px 14px;
  border-radius: 6px;
  cursor: pointer;
  transition: color 0.15s;
}
#btn-mp-leave:hover { color: var(--text); }

/* ── Leaderboard ── */
#leaderboard-area {
  display: none;
  min-width: 280px;
  max-width: 480px;
  width: 100%;
}

#lb-kind-tabs { display: flex; gap: 6px; margin-bottom: 10px; }
#lb-tabs { display: flex; gap: 6px; margin-bottom: 12px; }

.lb-kind-tab, .lb-tab {
  padding: 5px 14px;
  background: transparent;
  border: 1px solid var(--border);
  color: var(--muted);
  border-radius: 20px;
  cursor: pointer;
  font-size: 0.8rem;
  font-weight: 600;
  transition: all 0.15s;
}
.lb-kind-tab.active, .lb-tab.active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

#lb-table { width: 100%; border-collapse: collapse; font-size: 0.83rem; }
#lb-table th, #lb-table td {
  padding: 8px 10px;
  border-bottom: 1px solid var(--border);
  text-align: left;
}
#lb-table th { color: var(--yellow); font-weight: 600; }
#lb-table tr:hover td { background: var(--panel); }

.replay-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--accent2);
  padding: 2px 8px;
  border-radius: 4px;
  cursor: pointer;
  font-size: 0.8rem;
  transition: background 0.15s;
}
.replay-btn:hover { background: var(--accent); color: #fff; border-color: var(--accent); }

/* ── Settings panel ── */
#settings-panel {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.78);
  align-items: center;
  justify-content: center;
  z-index: 200;
}

#settings-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 28px;
  max-width: 400px;
  width: calc(100% - 32px);
  box-shadow: 0 20px 60px rgba(0,0,0,0.5);
  display: flex;
  flex-direction: column;
  gap: 20px;
  max-height: calc(100dvh - 48px);
  overflow-y: auto;
}

.settings-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.settings-header h2 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--yellow);
  text-transform: uppercase;
  letter-spacing: 2px;
}

#settings-close {
  background: transparent;
  border: none;
  color: var(--muted);
  font-size: 1.1rem;
  cursor: pointer;
  padding: 4px 6px;
  line-height: 1;
  border-radius: 4px;
}
#settings-close:hover { color: var(--text); }

.settings-section {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border);
}
.settings-section:last-child { border-bottom: none; padding-bottom: 0; }

.settings-label {
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 1.5px;
}

.settings-row {
  display: flex;
  gap: 8px;
}
.settings-row input {
  flex: 1;
  padding: 8px 12px;
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 6px;
  font-size: 0.88rem;
  min-width: 0;
}
.settings-row input:focus { outline: none; border-color: var(--accent2); }
.settings-row input::placeholder { color: var(--muted); }
.settings-row button {
  padding: 8px 14px;
  background: var(--accent);
  border: none;
  color: #fff;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.82rem;
  font-weight: 600;
  white-space: nowrap;
  transition: background 0.15s;
}
.settings-row button:hover { background: var(--accent2); }

#settings-colorscheme {
  padding: 8px 10px;
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 6px;
  font-size: 0.88rem;
  cursor: pointer;
}
#settings-colorscheme:focus { outline: none; border-color: var(--accent2); }

#color-swatches {
  display: flex;
  justify-content: space-around;
}
.swatch {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}
.swatch-dot {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  border: 2px solid rgba(255,255,255,0.12);
  transition: background 0.2s;
}
.swatch span {
  font-size: 0.68rem;
  color: var(--muted);
}

.toggle-group {
  display: flex;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  width: fit-content;
}
.toggle-btn {
  padding: 8px 22px;
  background: transparent;
  border: none;
  color: var(--muted);
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 600;
  transition: all 0.15s;
}
.toggle-btn + .toggle-btn { border-left: 1px solid var(--border); }
.toggle-btn.active { background: var(--accent); color: #fff; }
.toggle-btn:hover:not(.active) { color: var(--text); background: var(--panel); }

.settings-hint {
  font-size: 0.78rem;
  color: var(--muted);
  line-height: 1.5;
  min-height: 1.2em;
}

/* ── Modal ── */
#modal {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.78);
  align-items: center;
  justify-content: center;
  z-index: 200;
}

#modal-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 32px 28px;
  max-width: 360px;
  width: calc(100% - 32px);
  text-align: center;
  box-shadow: 0 20px 60px rgba(0,0,0,0.5);
}

#modal-title { font-size: 1.4rem; margin-bottom: 10px; color: var(--yellow); }
#modal-body  { margin-bottom: 22px; line-height: 1.6; color: var(--muted); }

#modal-close {
  padding: 9px 30px;
  background: var(--accent);
  border: none;
  color: #fff;
  border-radius: 6px;
  cursor: pointer;
  font-weight: 600;
  transition: background 0.15s;
}
#modal-close:hover { background: var(--accent2); }

/* ── Splash / onboarding ── */
#splash {
  display: none;
  position: fixed;
  inset: 0;
  background: var(--bg);
  align-items: center;
  justify-content: center;
  z-index: 500;
  padding: 16px;
}

#splash-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 36px 28px;
  max-width: 420px;
  width: 100%;
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 18px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.5);
}

#splash-box h1 {
  font-size: 2rem;
  letter-spacing: 4px;
  display: block;
  background: linear-gradient(135deg, var(--yellow), var(--red));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.splash-sub {
  color: var(--muted);
  font-size: 0.82rem;
  letter-spacing: 3px;
  text-transform: uppercase;
  margin-top: -10px;
}

.splash-rules {
  display: flex;
  flex-direction: column;
  gap: 9px;
  text-align: left;
  background: var(--panel);
  border-radius: 8px;
  padding: 14px 16px;
}

.rule { font-size: 0.88rem; line-height: 1.5; }

.splash-name {
  display: flex;
  gap: 8px;
}

.splash-name input {
  flex: 1;
  padding: 9px 12px;
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 6px;
  font-size: 0.9rem;
  min-width: 0;
}
.splash-name input:focus { outline: none; border-color: var(--accent2); }
.splash-name input::placeholder { color: var(--muted); }

.splash-name button {
  padding: 9px 16px;
  background: var(--accent);
  border: none;
  color: #fff;
  border-radius: 6px;
  cursor: pointer;
  font-weight: 600;
  font-size: 0.88rem;
  white-space: nowrap;
  transition: background 0.15s;
}
.splash-name button:hover { background: var(--accent2); }

#splash-play {
  padding: 12px;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  border: none;
  color: #fff;
  border-radius: 8px;
  cursor: pointer;
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 1px;
  transition: filter 0.15s;
}
#splash-play:hover { filter: brightness(1.1); }

.bmc-btn-splash {
  font-size: 0.78rem;
  color: var(--muted);
  text-decoration: none;
  text-align: center;
  transition: color 0.15s;
}
.bmc-btn-splash:hover { color: var(--yellow); }

.splash-options {
  display: flex;
  flex-direction: column;
  gap: 12px;
  text-align: left;
  background: var(--panel);
  border-radius: 8px;
  padding: 14px 16px;
}

.splash-option-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.splash-option-label {
  font-size: 0.8rem;
  color: var(--muted);
  white-space: nowrap;
}

#splash-color-swatches {
  display: flex;
  justify-content: space-around;
}

.splash-options select {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 5px 8px;
  font-size: 0.8rem;
  cursor: pointer;
}
.splash-options select:focus { outline: none; border-color: var(--accent2); }

.beta-badge {
  display: inline-block;
  background: var(--accent2);
  color: #fff;
  font-size: 0.6rem;
  font-weight: 700;
  letter-spacing: 0.5px;
  padding: 1px 5px;
  border-radius: 4px;
  vertical-align: middle;
  margin-left: 3px;
}

/* ── Drag demo animation ── */

#splash-drag-demo {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding-top: 4px;
}

.drag-demo {
  position: relative;
  width: 56px;
  height: 56px;
}

.drag-demo-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3px;
  width: 56px;
  height: 56px;
  border-radius: 4px;
  overflow: hidden;
  animation: demo-spin 2.6s ease-in-out infinite;
  transform-origin: center;
}

.drag-demo-cell:nth-child(1) { background: #e63946; }
.drag-demo-cell:nth-child(2) { background: #4895ef; }
.drag-demo-cell:nth-child(3) { background: #2ec4b6; }
.drag-demo-cell:nth-child(4) { background: #ffd166; }

.drag-demo-cursor {
  position: absolute;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: rgba(255,255,255,0.95);
  box-shadow: 0 0 0 3px rgba(255,255,255,0.25), 0 2px 8px rgba(0,0,0,0.5);
  top: 14px;
  left: 7px;
  margin: -7px 0 0 -7px;
  animation: demo-cursor 2.6s ease-in-out infinite;
  pointer-events: none;
}

@keyframes demo-spin {
  0%, 35%  { transform: rotate(0deg); }
  62%, 88% { transform: rotate(90deg); }
  100%     { transform: rotate(0deg); }
}

@keyframes demo-cursor {
  0%, 10% { transform: translateX(0);    opacity: 0; }
  22%     { transform: translateX(0);    opacity: 1; }
  52%     { transform: translateX(30px); opacity: 0.9; }
  62%     { transform: translateX(30px); opacity: 0; }
  100%    { transform: translateX(0);    opacity: 0; }
}

.drag-demo-label {
  font-size: 0.76rem;
  color: var(--muted);
  margin: 0;
  text-align: center;
  line-height: 1.4;
}
.drag-demo-label em {
  color: var(--accent2);
  font-style: normal;
  font-weight: 600;
}

/* ── Responsive ── */

/* Small phones: tighten padding and controls */
@media (max-width: 480px) {
  header { padding: 8px 12px; }
  h1 { font-size: 1.05rem; letter-spacing: 2px; }
  .mode-btn { padding: 4px 9px; font-size: 0.76rem; }
  main { padding: 8px; }
  #controls button { width: 42px; height: 42px; }
  #seed-input { display: none; } /* seed entry not practical on small screens */
}

/* Landscape mobile: shrink board so controls fit in viewport height */
@media (orientation: landscape) and (max-height: 520px) {
  header { padding: 6px 14px; }
  main { padding: 6px 10px; }
  #game-area { gap: 6px; }
  #board-wrap {
    width: min(calc(100dvh - 120px), calc(100vw - 32px), 900px);
  }
  #mode-controls { display: none; }
}

/* Large screens: allow board to breathe more */
@media (min-width: 1200px) {
  main { padding: 24px; }
  #game-area { gap: 14px; }
}