:root {
  color-scheme: light;
  --bg: #f4f6fb;
  --panel: #ffffff;
  --text: #1b1f2a;
  --muted: #5d6472;
  --border: #d8dce6;
  --dead: #f1f3f7;
  --cols: 30;
  --rows: 20;
  --cell: 20px;
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  background: radial-gradient(circle at 20% 10%, #e9f7ef 0%, var(--bg) 45%);
  color: var(--text);
}

.app {
  max-width: 1080px;
  margin: 0 auto;
  padding: 16px;
  min-height: 100dvh;
}

h1 {
  margin: 0 0 14px;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px;
  margin-bottom: 14px;
}

.row {
  display: flex;
  gap: 10px;
  align-items: center;
  margin-bottom: 10px;
}

.row label,
.color-label {
  min-width: 56px;
}

input,
select {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px;
  width: 100%;
  background: #fff;
}

input[type="checkbox"] {
  width: 18px;
  height: 18px;
  padding: 0;
}

button {
  border: none;
  border-radius: 8px;
  background: #1f6feb;
  color: #fff;
  padding: 10px 12px;
  cursor: pointer;
  font-weight: 600;
}

button:hover {
  filter: brightness(0.96);
}

.actions button {
  width: 100%;
}

.join-row input {
  flex: 1;
}

.error {
  color: #c62828;
  min-height: 1.25em;
}

.color-row {
  align-items: flex-start;
}

.color-picker {
  display: grid;
  grid-template-columns: repeat(5, 28px);
  gap: 8px;
}

.color-swatch {
  width: 28px;
  height: 28px;
  border-radius: 6px;
  border: 2px solid transparent;
  padding: 0;
}

.color-swatch.selected {
  border-color: #111827;
}

.color-swatch:disabled {
  opacity: 0.25;
  cursor: not-allowed;
}

.status-grid {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.toolbar {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  margin-bottom: 8px;
}

.board-wrap {
  width: 100%;
  overflow: auto;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: #d8dce6;
  padding: 8px;
}

.board-viewport {
  position: relative;
  width: 100%;
  overflow: auto;
}

.board {
  display: grid;
  grid-template-columns: repeat(var(--cols), var(--cell));
  grid-template-rows: repeat(var(--rows), var(--cell));
  gap: 1px;
  margin: 0 auto;
  width: fit-content;
}

.cell {
  width: var(--cell);
  height: var(--cell);
  border: none;
  margin: 0;
  padding: 0;
  cursor: pointer;
  background: var(--dead);
}

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

.cell.locked {
  cursor: not-allowed;
}

.cell-impact {
  animation: expand-shadow 280ms ease-out;
}

@keyframes expand-shadow {
  0% {
    box-shadow: 0 0 0 0 rgba(15, 23, 42, 0.45);
    transform: scale(0.92);
  }
  70% {
    box-shadow: 0 0 0 10px rgba(15, 23, 42, 0);
    transform: scale(1.03);
  }
  100% {
    box-shadow: 0 0 0 0 rgba(15, 23, 42, 0);
    transform: scale(1);
  }
}

.winner-overlay {
  position: absolute;
  inset: 0;
  display: none;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  font-weight: 700;
  color: #ffffff;
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.7);
  background: rgba(2, 6, 23, 0.35);
  pointer-events: none;
}

.legend {
  margin-top: 10px;
  display: flex;
  gap: 14px;
  color: var(--muted);
  flex-wrap: wrap;
}

.legend span {
  display: inline-flex;
  align-items: center;
}

.swatch {
  display: inline-block;
  width: 10px;
  height: 10px;
  margin-right: 6px;
  border-radius: 2px;
}

.swatch.dead {
  background: var(--dead);
  border: 1px solid #c6cbd8;
}

.fullscreen-footer {
  display: none;
}

.board-wrap:fullscreen {
  width: 100dvw;
  height: 100dvh;
  border-radius: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
}

.board-wrap:fullscreen .board-viewport {
  flex: 1;
  padding: 8px;
}

.board-wrap:fullscreen .fullscreen-footer {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  background: #0f172a;
  color: #f8fafc;
  min-height: 56px;
  padding: 10px 14px;
  border-top: 1px solid #1e293b;
}

.footer-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 8px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.08);
  font-size: 0.9rem;
}

.hidden {
  display: none !important;
}

.public-lobbies {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 8px;
  background: #fafbfd;
  max-height: 220px;
  overflow: auto;
}

.public-lobby-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 6px 0;
  border-bottom: 1px solid #eceff5;
}

.public-lobby-row:last-child {
  border-bottom: none;
}

.rules-drawer {
  position: fixed;
  top: 0;
  right: 0;
  width: min(360px, 92vw);
  height: 100dvh;
  background: #ffffff;
  border-left: 1px solid var(--border);
  box-shadow: -10px 0 30px rgba(15, 23, 42, 0.15);
  transform: translateX(100%);
  transition: transform 220ms ease-in-out;
  z-index: 50;
  display: flex;
  flex-direction: column;
}

.rules-drawer.open {
  transform: translateX(0);
}

.rules-handle {
  position: fixed;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
  z-index: 60;
  border-radius: 8px 0 0 8px;
  padding: 10px 8px;
  min-width: 32px;
  background: #0f172a;
}

.rules-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px;
  border-bottom: 1px solid var(--border);
}

.rules-header h3 {
  margin: 0;
}

.rules-body {
  padding: 12px;
  overflow: auto;
}

.rule-item {
  margin: 0 0 8px;
}

.example-card {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px;
  margin-bottom: 8px;
  background: #f9fbff;
}

.example-title {
  font-weight: 600;
  margin-bottom: 6px;
}

.example-grids {
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
}

.mini-grid-wrap {
  display: flex;
  flex-direction: column;
  gap: 4px;
  align-items: center;
}

.mini-grid-label {
  font-size: 0.78rem;
  color: #475569;
}

.mini-grid {
  display: grid;
  grid-template-columns: repeat(5, 12px);
  grid-template-rows: repeat(5, 12px);
  gap: 1px;
}

.mini-cell {
  width: 12px;
  height: 12px;
  background: #e2e8f0;
  border-radius: 2px;
}

.mini-cell.a {
  background: #22c55e;
}

.mini-cell.b {
  background: #3b82f6;
}

.example-note {
  margin-top: 6px;
  font-size: 0.82rem;
  color: #475569;
}

@media (max-width: 700px) {
  .status-grid {
    gap: 0;
    flex-direction: column;
  }

  .color-picker {
    grid-template-columns: repeat(5, 24px);
  }

  .color-swatch {
    width: 24px;
    height: 24px;
  }
}