:root {
  color-scheme: dark;
  --bg: #07090d;
  --panel: #0d121a;
  --panel-2: #111923;
  --cell: #0a0f16;
  --line: #26384b;
  --line-bright: #61d6ff;
  --text: #d9f7ff;
  --muted: #7e9aa8;
  --x: #ff5f8f;
  --o: #47e5bc;
  --warn: #ffd166;
  --ok: #7cff6b;
  --bad: #ff6b6b;
  --focus: #f7f052;
  --shadow: 0 0 0 1px rgba(97, 214, 255, 0.18), 0 18px 48px rgba(0, 0, 0, 0.4);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  background:
    linear-gradient(rgba(97, 214, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(97, 214, 255, 0.035) 1px, transparent 1px),
    radial-gradient(circle at 50% 0%, rgba(71, 229, 188, 0.12), transparent 30rem),
    var(--bg);
  background-size: 24px 24px, 24px 24px, auto, auto;
  font-family: "Cascadia Mono", Consolas, "Courier New", monospace;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background: repeating-linear-gradient(
    to bottom,
    rgba(255, 255, 255, 0.035),
    rgba(255, 255, 255, 0.035) 1px,
    transparent 1px,
    transparent 4px
  );
  opacity: 0.22;
  mix-blend-mode: screen;
}

button {
  font: inherit;
}

.app {
  width: min(920px, calc(100vw - 28px));
  min-height: 100vh;
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 260px;
  gap: 14px;
  align-items: center;
  padding: 20px 0;
}

.play-area,
.side-panel {
  background: linear-gradient(180deg, rgba(17, 25, 35, 0.94), rgba(8, 12, 18, 0.98));
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.play-area {
  padding: 16px;
}

.side-panel {
  padding: 12px;
}

.topbar,
.status-row,
.score-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.eyebrow {
  margin: 0 0 4px;
  color: var(--o);
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  color: var(--text);
  font-size: clamp(1.9rem, 4vw, 3.2rem);
  line-height: 0.95;
  text-transform: uppercase;
  text-shadow: 0 0 12px rgba(97, 214, 255, 0.55);
}

.icon-button {
  width: 46px;
  height: 32px;
  display: inline-grid;
  place-items: center;
  border: 1px solid var(--line-bright);
  border-radius: 2px;
  color: var(--line-bright);
  background: #05080d;
  cursor: pointer;
  font-size: 0.72rem;
  font-weight: 800;
  transition: background 120ms ease, color 120ms ease, box-shadow 120ms ease;
}

.icon-button:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.icon-button:hover:not(:disabled) {
  color: #061016;
  background: var(--line-bright);
  box-shadow: 0 0 18px rgba(97, 214, 255, 0.45);
}

.icon-button:focus-visible,
.cell:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
}

.status-row {
  margin: 14px 0 10px;
}

.turn-badge {
  min-width: 128px;
  padding: 7px 9px;
  border: 1px solid currentColor;
  border-radius: 2px;
  font-size: 0.78rem;
  font-weight: 800;
  text-align: center;
  text-transform: uppercase;
}

.player-x {
  color: var(--x);
  background: rgba(255, 95, 143, 0.08);
}

.player-o {
  color: var(--o);
  background: rgba(71, 229, 188, 0.08);
}

.message {
  color: var(--muted);
  font-size: 0.78rem;
  text-align: right;
  line-height: 1.35;
}

.network-status {
  margin: 0 0 12px;
  padding: 8px 10px;
  border: 1px solid var(--line);
  border-radius: 2px;
  color: var(--muted);
  background: #070b11;
  font-size: 0.74rem;
  font-weight: 800;
  text-transform: uppercase;
}

.network-status::before {
  content: "> ";
}

.network-status.paired {
  color: var(--ok);
  border-color: rgba(124, 255, 107, 0.5);
}

.network-status.waiting,
.network-status.connecting {
  color: var(--warn);
  border-color: rgba(255, 209, 102, 0.5);
}

.network-status.error {
  color: var(--bad);
  border-color: rgba(255, 107, 107, 0.55);
}

.board {
  aspect-ratio: 1;
  width: min(100%, 520px);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  grid-template-rows: repeat(5, 1fr);
  border: 2px solid var(--line-bright);
  background: var(--line-bright);
  gap: 2px;
  box-shadow: 0 0 24px rgba(97, 214, 255, 0.22);
}

.cell {
  min-width: 0;
  border: 0;
  display: grid;
  place-items: center;
  background: var(--cell);
  color: var(--text);
  cursor: pointer;
  position: relative;
  isolation: isolate;
}

.cell::before {
  content: "+";
  position: absolute;
  color: rgba(126, 154, 168, 0.25);
  font-size: 0.9rem;
}

.cell:hover:not([disabled]) {
  background: #101926;
}

.cell:hover:not([disabled])::before {
  color: var(--line-bright);
}

.cell[disabled] {
  cursor: default;
}

.mark {
  display: grid;
  place-items: center;
  width: 80%;
  height: 80%;
  font-size: clamp(1.75rem, 6vw, 3.25rem);
  font-weight: 900;
  line-height: 1;
  animation: pop 120ms steps(2, end);
}

.mark-x {
  color: var(--x);
  text-shadow: 0 0 12px rgba(255, 95, 143, 0.65);
}

.mark-o {
  color: var(--o);
  text-shadow: 0 0 12px rgba(71, 229, 188, 0.65);
}

.cell.captured {
  animation: capture 300ms steps(3, end);
}

.cell.winning {
  background: #1b2440;
  box-shadow: inset 0 0 0 3px var(--focus);
}

.score-row {
  margin-bottom: 10px;
}

.score-box {
  flex: 1;
  padding: 9px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: var(--panel-2);
}

.score-label {
  display: block;
  color: var(--muted);
  font-size: 0.62rem;
  font-weight: 800;
  text-transform: uppercase;
}

.score-box strong {
  display: block;
  margin-top: 2px;
  color: var(--text);
  font-size: 1.45rem;
  line-height: 1;
}

.rule-card {
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: #070b11;
}

.rule-card h2 {
  margin: 0 0 7px;
  color: var(--line-bright);
  font-size: 0.76rem;
}

.rule-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.72rem;
  line-height: 1.45;
}

.move-list {
  max-height: 250px;
  margin: 10px 0 0;
  padding: 0;
  overflow: auto;
  color: var(--muted);
  font-size: 0.72rem;
  list-style: none;
}

.move-list li {
  margin-bottom: 5px;
  padding: 5px 7px;
  border-left: 2px solid var(--line);
  background: rgba(97, 214, 255, 0.04);
}

.move-list li::before {
  content: "$ ";
  color: var(--o);
}

@keyframes pop {
  from {
    opacity: 0;
    transform: scale(0.7);
  }
}

@keyframes capture {
  35% {
    background: var(--bad);
  }
}

@media (max-width: 780px) {
  .app {
    min-height: auto;
    grid-template-columns: 1fr;
    align-items: start;
    padding: 14px 0;
  }

  .play-area,
  .side-panel {
    padding: 12px;
  }

  .status-row {
    align-items: flex-start;
    flex-direction: column;
  }

  .message {
    text-align: left;
  }

  h1 {
    font-size: 2.2rem;
  }

  .board {
    width: min(100%, 430px);
  }

  .move-list {
    max-height: 150px;
  }
}