:root {
  color-scheme: light;
  --bg: #f4efe6;
  --bg-deep: #e9ddca;
  --card: #fffaf2;
  --card-soft: rgba(255, 250, 242, 0.72);
  --ink: #2a2118;
  --muted: #7b6c5c;
  --line: #e4d8c7;
  --accent: #a4481f;
  --accent-strong: #873512;
  --accent-soft: rgba(164, 72, 31, 0.12);
  --green: #2f6b4f;
  --green-soft: rgba(47, 107, 79, 0.13);
  --danger: #b23a2f;
  --shadow: 0 18px 45px rgba(80, 56, 30, 0.13);
  --radius: 18px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;
    --bg: #17130f;
    --bg-deep: #211a14;
    --card: #241c15;
    --card-soft: rgba(36, 28, 21, 0.82);
    --ink: #f0e8dc;
    --muted: #b7a38c;
    --line: #3a2d22;
    --accent: #e08a5b;
    --accent-strong: #f0a273;
    --accent-soft: rgba(224, 138, 91, 0.16);
    --green: #7cc39a;
    --green-soft: rgba(124, 195, 154, 0.16);
    --danger: #ef8b7e;
    --shadow: 0 18px 45px rgba(0, 0, 0, 0.35);
  }
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  min-height: 100vh;
  min-height: 100dvh;
  color: var(--ink);
  font-family: var(--font);
  background:
    radial-gradient(circle at 12% 8%, rgba(255, 255, 255, 0.72), transparent 34%),
    radial-gradient(circle at 88% 0%, rgba(228, 189, 127, 0.28), transparent 38%),
    linear-gradient(160deg, var(--bg), var(--bg-deep));
  -webkit-tap-highlight-color: transparent;
  -webkit-font-smoothing: antialiased;
}

@media (prefers-color-scheme: dark) {
  body {
    background:
      radial-gradient(circle at 12% 8%, rgba(255, 255, 255, 0.06), transparent 34%),
      radial-gradient(circle at 88% 0%, rgba(228, 189, 127, 0.12), transparent 38%),
      linear-gradient(160deg, var(--bg), var(--bg-deep));
  }
}

button,
input {
  font: inherit;
}

button {
  -webkit-appearance: none;
  appearance: none;
}

button:focus-visible,
input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.hidden {
  display: none !important;
}

/* 首页 */

.home {
  width: min(100% - 36px, 430px);
  margin: 0 auto;
  padding: clamp(28px, 7vh, 64px) 0 calc(24px + env(safe-area-inset-bottom, 0px));
}

.brand {
  margin-bottom: 22px;
  text-align: center;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 66px;
  height: 66px;
  margin: 0 auto 14px;
  border-radius: 22px;
  background: linear-gradient(145deg, #d58a4a, #9e3f18);
  box-shadow: 0 14px 26px rgba(164, 72, 31, 0.28);
  color: #fff7ec;
  font-size: 30px;
  font-weight: 800;
  transform: rotate(-3deg);
}

h1 {
  margin: 0;
  font-size: clamp(34px, 10vw, 44px);
  letter-spacing: 0.04em;
}

.tagline {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.card {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--card);
  box-shadow: var(--shadow);
}

.field-label {
  display: block;
  margin: 0 0 6px;
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 0.04em;
}

.input {
  width: 100%;
  height: 46px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--bg);
  color: var(--ink);
  font-size: 16px;
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.input::placeholder {
  color: var(--muted);
  opacity: 0.72;
}

.btn {
  min-height: 46px;
  padding: 0 18px;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: var(--card);
  color: var(--ink);
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.12s ease, background 0.2s ease, opacity 0.2s ease;
}

.btn:active {
  transform: scale(0.97);
}

.btn:disabled {
  cursor: default;
  opacity: 0.55;
}

.btn.primary {
  border-color: transparent;
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  box-shadow: 0 10px 22px rgba(164, 72, 31, 0.22);
  color: #fff;
}

.btn.ghost {
  background: transparent;
}

.btn.danger {
  border-color: var(--danger);
  background: transparent;
  color: var(--danger);
}

@media (prefers-color-scheme: dark) {
  .btn.primary {
    color: #24140b;
  }

  .brand-mark {
    color: #2a160c;
  }
}

.wide {
  width: 100%;
  margin-top: 14px;
}

.divider {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 20px 0;
  color: var(--muted);
  font-size: 12px;
}

.divider::before,
.divider::after {
  flex: 1;
  height: 1px;
  background: var(--line);
  content: "";
}

.join-row {
  display: flex;
  gap: 10px;
}

.join-row .input {
  flex: 1;
  min-width: 0;
}

.code-input {
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.error {
  min-height: 20px;
  margin: 10px 0 0;
  color: var(--danger);
  font-size: 13px;
}

.rules {
  margin-top: 26px;
  padding: 18px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--card-soft);
}

.rules h2 {
  margin: 0 0 6px;
  font-size: 14px;
}

.rules p {
  margin: 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.7;
}

.footnote {
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 11px;
  letter-spacing: 0.04em;
  text-align: center;
}

/* 房间页 */

.room-page {
  padding-bottom: env(safe-area-inset-bottom, 0px);
}

.room-bar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: calc(10px + env(safe-area-inset-top, 0px)) 14px 10px;
  border-bottom: 1px solid var(--line);
  background: var(--bg);
}

.icon-btn {
  min-width: 40px;
  height: 40px;
  padding: 0 6px;
  border: 0;
  border-radius: 12px;
  background: transparent;
  color: var(--ink);
  font-size: 19px;
  cursor: pointer;
}

.text-btn {
  color: var(--muted);
  font-size: 12px;
}

.room-heading {
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 0;
}

.room-label {
  color: var(--muted);
  font-size: 10px;
  letter-spacing: 0.08em;
}

.room-code {
  font-size: 15px;
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  letter-spacing: 0.14em;
}

.badge {
  padding: 3px 8px;
  border-radius: 999px;
  background: var(--line);
  color: var(--muted);
  font-size: 11px;
  white-space: nowrap;
}

.badge.waiting {
  background: var(--accent-soft);
  color: var(--accent);
}

.badge.playing,
.badge.your-turn {
  background: var(--green-soft);
  color: var(--green);
}

.badge.your-turn {
  font-weight: 700;
}

.badge.spectating,
.badge.finished {
  background: var(--line);
  color: var(--muted);
}

.room {
  width: min(100% - 28px, 560px);
  margin: 0 auto;
  padding: 14px 0 calc(24px + env(safe-area-inset-bottom, 0px));
}

.players {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 12px;
}

.player {
  display: flex;
  align-items: center;
  gap: 9px;
  min-width: 0;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--card);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.player.active {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.stone-dot {
  flex: 0 0 auto;
  width: 18px;
  height: 18px;
  border-radius: 50%;
}

.stone-dot.black {
  background: #1f1f1f;
}

.stone-dot.white {
  border: 1px solid #bdb5a8;
  background: #f7f7f7;
}

.player-meta {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.player-color {
  color: var(--muted);
  font-size: 10px;
}

.player-name {
  overflow: hidden;
  font-size: 14px;
  font-weight: 600;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.turn-dot {
  width: 7px;
  height: 7px;
  margin-left: auto;
  border-radius: 50%;
  background: var(--accent);
  opacity: 0;
  transition: opacity 0.2s ease;
}

.player.active .turn-dot {
  opacity: 1;
}

.board-wrap {
  position: relative;
  width: 100%;
  aspect-ratio: 1 / 1;
  overflow: hidden;
  border-radius: 20px;
  background: #e4bd7f;
  box-shadow: var(--shadow);
}

#board {
  display: block;
  width: 100%;
  height: 100%;
  touch-action: manipulation;
  user-select: none;
  -webkit-user-select: none;
}

#board.interactive {
  cursor: crosshair;
}

.status-text {
  min-height: 22px;
  margin: 14px 0 0;
  text-align: center;
  font-size: 15px;
  font-weight: 600;
}

.hint {
  min-height: 18px;
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 12px;
  text-align: center;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-top: 16px;
}

.join-panel {
  margin-top: 16px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--card);
}

.join-panel .join-row {
  margin-top: 2px;
}

.link-btn {
  display: block;
  margin: 10px auto 0;
  padding: 6px;
  border: 0;
  background: transparent;
  color: var(--muted);
  font-size: 12px;
  text-decoration: underline;
  cursor: pointer;
}

.overlay {
  margin-top: 12px;
}

.overlay.fatal {
  position: fixed;
  inset: 0;
  z-index: 70;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: 0;
  padding: 20px;
  background: rgba(20, 14, 8, 0.66);
}

.overlay.fatal .overlay-card {
  width: min(100%, 420px);
}

.overlay-card {
  width: 100%;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--card);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.25);
}

.overlay-kicker {
  margin: 0 0 3px;
  color: var(--muted);
  font-size: 11px;
  letter-spacing: 0.08em;
}

.overlay-card h2 {
  margin: 0;
  font-size: 24px;
}

.overlay-card p {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.overlay-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 12px;
}

.toast {
  position: fixed;
  bottom: calc(24px + env(safe-area-inset-bottom, 0px));
  left: 50%;
  z-index: 50;
  max-width: calc(100vw - 48px);
  padding: 10px 16px;
  transform: translateX(-50%);
  border-radius: 999px;
  background: rgba(30, 22, 14, 0.92);
  color: #fff;
  font-size: 13px;
  text-align: center;
}

.network-banner {
  position: fixed;
  top: 0;
  right: 0;
  left: 0;
  z-index: 60;
  padding: calc(9px + env(safe-area-inset-top, 0px)) 12px 9px;
  background: #ffd97a;
  color: #5a3b00;
  font-size: 12px;
  text-align: center;
}

.copy-fallback {
  position: fixed;
  inset: 0;
  z-index: 80;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  background: rgba(20, 14, 8, 0.55);
}

.copy-card {
  width: min(100%, 420px);
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--card);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.25);
}

.copy-card p {
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 13px;
}

.copy-card .input {
  margin-bottom: 10px;
}

.copy-card .btn {
  width: 100%;
}

@media (min-width: 720px) {
  .room {
    padding-top: 24px;
  }

  .players {
    gap: 14px;
  }

  .player {
    padding: 12px 16px;
  }

  .status-text {
    font-size: 16px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition: none !important;
  }
}