:root {
  --bg: #0b0d0c;
  --bg-soft: #101412;
  --line: rgba(255, 255, 255, 0.075);
  --line-strong: rgba(255, 255, 255, 0.14);
  --text: #eef0e8;
  --muted: #9aa398;
  --dim: #8f998b;
  --olive: #9adb37;
  --olive-soft: rgba(154, 219, 55, 0.16);
  --melon: #fc0377;
  --melon-soft: rgba(252, 3, 119, 0.16);
  --light-sq: #ebecd0;
  --dark-sq: #739552;
  --hl-last: rgba(255, 234, 84, 0.6);
  --hl-select: rgba(37, 111, 226, 0.55);
  --radius: 18px;
  --serif: "Iowan Old Style", "Palatino Linotype", "Songti SC", "SimSun", Georgia, serif;
  --sans: "Segoe UI", "Microsoft YaHei", "PingFang SC", "Hiragino Sans GB", sans-serif;
  --mono: "Cascadia Mono", "JetBrains Mono", Consolas, "Courier New", monospace;
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html {
  -webkit-text-size-adjust: 100%;
  color-scheme: dark;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 14px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(900px 620px at 84% -12%, rgba(154, 219, 55, 0.1), transparent 62%),
    radial-gradient(720px 520px at -12% 94%, rgba(252, 3, 119, 0.055), transparent 62%),
    linear-gradient(180deg, #0c0f0d, #090b0a 60%);
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.032;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)' opacity='0.55'/%3E%3C/svg%3E");
}

button {
  font-family: inherit;
}

.shell {
  position: relative;
  z-index: 1;
  --board-size: min(860px, max(360px, calc(100vh - 220px)), 100%);
  max-width: 1120px;
  margin: 0 auto;
  padding: 28px 24px 64px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  width: 100%;
  max-width: var(--board-size);
  margin: 0 auto 18px;
  animation: rise 0.5s ease both;
}

.top-actions {
  display: flex;
  align-items: center;
  gap: 4px;
  flex: 0 0 auto;
}

.nav-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 6px 8px;
  border: 1px solid transparent;
  border-radius: 8px;
  background: transparent;
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 0.03em;
  white-space: nowrap;
  cursor: pointer;
  transition: color 0.16s, background 0.16s;
}

.nav-btn:hover {
  color: var(--text);
  background: rgba(255, 255, 255, 0.045);
}

.nav-btn:focus-visible {
  outline: 2px solid var(--olive);
  outline-offset: 2px;
}

.nav-count {
  font-size: 10px;
  color: var(--dim);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 13px;
  flex: 0 0 auto;
}

.brand-mark {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  grid-template-rows: repeat(2, 1fr);
  gap: 2px;
  width: 30px;
  height: 30px;
  padding: 0;
  transform: rotate(45deg);
  border-radius: 6px;
  overflow: hidden;
  box-shadow: 0 6px 18px -8px rgba(154, 219, 55, 0.7);
}

.brand-mark span {
  background: var(--olive);
  opacity: 0.9;
}

.brand-mark span:nth-child(2),
.brand-mark span:nth-child(3) {
  opacity: 0.32;
}

.brand-mark span:nth-child(4) {
  background: var(--melon);
  opacity: 0.9;
}

h1 {
  margin: 0;
  font-family: var(--serif);
  font-size: 32px;
  font-weight: 600;
  letter-spacing: 0.06em;
  line-height: 1;
  white-space: nowrap;
}

.layout {
  display: block;
}

.board-column {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
  animation: rise 0.55s ease 0.05s both;
}

.player-strip {
  display: flex;
  align-items: center;
  gap: 9px;
  width: var(--board-size);
  max-width: 100%;
  padding: 7px 3px;
  min-height: 32px;
}

.player-dot {
  width: 6px;
  height: 6px;
  flex: 0 0 auto;
  border-radius: 50%;
  background: var(--line-strong);
  transition: background 0.2s, box-shadow 0.2s;
}

.player-strip.is-active .player-dot {
  background: var(--olive);
  box-shadow: 0 0 0 3px var(--olive-soft);
}

.player-name {
  font-size: 13px;
  font-weight: 600;
  color: var(--muted);
  letter-spacing: 0.02em;
  white-space: nowrap;
  transition: color 0.2s;
}

.player-strip.is-active .player-name {
  color: var(--text);
}

.player-state {
  flex: 0 0 auto;
  padding: 3px 7px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-size: 10px;
  line-height: 1.1;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.player-state.state-check {
  color: #ffd0e4;
  background: rgba(252, 3, 119, 0.1);
  border-color: rgba(252, 3, 119, 0.38);
}

.player-state.state-thinking {
  color: var(--olive);
  background: var(--olive-soft);
  border-color: rgba(154, 219, 55, 0.3);
}

.captures {
  display: flex;
  align-items: center;
  gap: 1px;
  flex: 1;
  min-width: 0;
  overflow: hidden;
  padding-left: 4px;
}

.capture-piece.piece {
  width: 17px;
  height: 17px;
  flex: 0 0 auto;
  opacity: 0.82;
}

.capture-piece.piece svg {
  filter: none;
}

.material-badge {
  margin-right: 6px;
  font-family: var(--mono);
  font-size: 10px;
  color: var(--olive);
  background: rgba(154, 219, 55, 0.1);
  border-radius: 5px;
  padding: 1px 5px;
  white-space: nowrap;
  flex: 0 0 auto;
}

.board-frame {
  position: relative;
  width: var(--board-size);
  max-width: 100%;
  padding: 9px;
  border-radius: 20px;
  background: linear-gradient(160deg, #222a23, #0f1310 58%);
  border: 1px solid rgba(255, 255, 255, 0.07);
  box-shadow:
    0 44px 80px -46px rgba(0, 0, 0, 0.95),
    0 1px 0 rgba(255, 255, 255, 0.05) inset;
}

.board {
  display: flex;
  flex-direction: column;
  aspect-ratio: 1 / 1;
  border-radius: 12px;
  overflow: hidden;
  touch-action: none;
  position: relative;
  box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.4) inset;
}

.srow {
  display: grid;
  grid-template-columns: repeat(8, minmax(0, 1fr));
  min-height: 0;
  flex: 1;
}

.board::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 4;
  border-radius: 12px;
  box-shadow:
    0 0 0 1px rgba(0, 0, 0, 0.28) inset,
    0 0 34px rgba(0, 0, 0, 0.14) inset;
  background: linear-gradient(140deg, rgba(255, 255, 255, 0.05), transparent 38%);
}

.sq {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 0;
  min-height: 0;
}

.sq.light {
  background: var(--light-sq);
}

.sq.dark {
  background: var(--dark-sq);
}

.sq::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  transition: background 0.14s ease;
}

.sq.last::before {
  background: var(--hl-last);
}

.sq.selected::before {
  background: var(--hl-select);
}

.sq.hint::before {
  background: rgba(154, 219, 55, 0.16);
  box-shadow: 0 0 0 3px rgba(154, 219, 55, 0.85) inset;
  animation: hintPulse 1s ease-in-out infinite;
}

.sq.in-check::before {
  background:
    radial-gradient(circle at 50% 50%, rgba(232, 66, 54, 0.72), rgba(232, 66, 54, 0) 76%),
    rgba(252, 3, 119, 0.3);
  animation: checkPulse 1s ease-in-out infinite;
}

.sq.target::after {
  content: "";
  width: 24%;
  height: 24%;
  border-radius: 50%;
  background: rgba(12, 17, 12, 0.32);
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.06);
  z-index: 1;
  pointer-events: none;
}

.sq.target-capture::after {
  content: "";
  position: absolute;
  inset: 5%;
  border-radius: 50%;
  border: 4px solid rgba(12, 17, 12, 0.4);
  z-index: 1;
  pointer-events: none;
}

.coord {
  position: absolute;
  z-index: 3;
  font-family: var(--mono);
  font-size: 10px;
  font-weight: 600;
  line-height: 1;
  opacity: 0.85;
  pointer-events: none;
}

.coord-rank {
  top: 4px;
  left: 5px;
}

.coord-file {
  right: 5px;
  bottom: 4px;
}

.sq.light .coord {
  color: #5f7a3c;
}

.sq.dark .coord {
  color: #f2f3de;
}

.sq.kbfocus::before {
  background: transparent;
  box-shadow: 0 0 0 3px rgba(154, 219, 55, 0.9) inset;
}

.board:focus-visible {
  outline: 2px solid var(--olive);
  outline-offset: 2px;
}

.board.is-thinking .piece {
  cursor: wait;
}

.piece {
  position: relative;
  z-index: 2;
  width: 86%;
  height: 86%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: grab;
  transition: transform 0.12s ease, filter 0.12s ease;
  will-change: transform;
}

.piece svg {
  width: 100%;
  height: 100%;
  display: block;
  filter: drop-shadow(0 2px 1.5px rgba(0, 0, 0, 0.28));
}

.piece.dragging {
  z-index: 30;
  cursor: grabbing;
  transition: none;
  filter: drop-shadow(0 16px 18px rgba(0, 0, 0, 0.45));
}

.piece.arrive {
  animation: pieceIn 0.18s ease-out;
}

.board-overlay {
  position: absolute;
  inset: 0;
  z-index: 50;
  display: grid;
  place-items: center;
  padding: 20px;
  border-radius: 20px;
  background: rgba(7, 9, 8, 0.66);
  backdrop-filter: blur(7px);
  -webkit-backdrop-filter: blur(7px);
  animation: fadeIn 0.2s ease both;
}

.result-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 30px 40px;
  min-width: 240px;
  border-radius: 20px;
  border: 1px solid var(--line-strong);
  background: linear-gradient(180deg, rgba(30, 36, 31, 0.96), rgba(16, 20, 17, 0.98));
  box-shadow: 0 30px 60px -24px #000;
  text-align: center;
}

.result-card h2 {
  margin: 4px 0 0;
  font-family: var(--serif);
  font-size: 30px;
  font-weight: 600;
  letter-spacing: 0.06em;
}

.result-card p {
  margin: 0 0 14px;
  color: var(--muted);
  font-size: 13px;
}

.card-label {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--dim);
  text-transform: uppercase;
}

.ghost-btn {
  border: 0;
  background: transparent;
  color: var(--muted);
  font-size: 11px;
  letter-spacing: 0.06em;
  padding: 3px 0;
  cursor: pointer;
  border-bottom: 1px solid transparent;
  transition: color 0.16s, border-color 0.16s;
}

.ghost-btn:hover {
  color: var(--olive);
  border-color: rgba(154, 219, 55, 0.4);
}

.btn {
  appearance: none;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.035);
  color: var(--text);
  border-radius: 10px;
  padding: 10px 8px;
  font-size: 12.5px;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: background 0.16s, border-color 0.16s, color 0.16s;
  white-space: nowrap;
}

.btn:hover {
  background: rgba(255, 255, 255, 0.075);
  border-color: var(--line-strong);
}

.btn:disabled {
  opacity: 0.42;
  cursor: not-allowed;
}

.btn:disabled:hover {
  background: rgba(255, 255, 255, 0.035);
  border-color: var(--line);
}

.btn:focus-visible,
.ghost-btn:focus-visible {
  outline: 2px solid var(--olive);
  outline-offset: 2px;
}

.btn-primary {
  background: var(--olive);
  border-color: transparent;
  color: #131708;
  font-weight: 600;
}

.btn-primary:hover {
  background: #a9e84d;
  border-color: transparent;
}

.btn-wide {
  width: 100%;
  padding: 12px;
  border-radius: 11px;
  font-size: 13px;
}

.fab {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 80;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 20px;
  border-radius: 999px;
  border: 1px solid rgba(0, 0, 0, 0.2);
  background: var(--olive);
  color: #131708;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.03em;
  cursor: pointer;
  box-shadow: 0 16px 34px -14px rgba(154, 219, 55, 0.65);
  transition: background 0.16s;
}

.fab:hover {
  background: #a9e84d;
}

.fab:focus-visible {
  outline: 2px solid var(--text);
  outline-offset: 3px;
}

:root[data-theme="melon"] .fab {
  color: #fff;
  box-shadow: 0 16px 34px -14px rgba(252, 3, 119, 0.7);
}

:root[data-theme="melon"] .fab:hover {
  background: #ff3d95;
}

.modal-card.settings-card {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  text-align: left;
  gap: 10px;
  min-width: 320px;
}

.modal-card.settings-card .card-label {
  text-align: left;
}

.modal-card.settings-card .setting-row {
  text-align: left;
}

.modal-card.settings-card .btn-wide {
  margin-top: 4px;
}

.setting-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
}

.setting-row + .setting-row {
  border-top: 1px solid rgba(255, 255, 255, 0.045);
  padding-top: 10px;
}

.setting-name {
  font-size: 13px;
  color: var(--muted);
}

.segmented {
  display: inline-flex;
  gap: 2px;
  padding: 3px;
  border-radius: 9px;
  background: rgba(0, 0, 0, 0.28);
  border: 1px solid rgba(255, 255, 255, 0.04);
}

.segmented button {
  border: 0;
  background: transparent;
  color: var(--muted);
  font-size: 11.5px;
  padding: 6px 12px;
  border-radius: 7px;
  cursor: pointer;
  transition: background 0.16s, color 0.16s;
}

.segmented button:hover {
  color: var(--text);
}

.segmented button.is-active {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text);
}

.segmented.is-disabled {
  opacity: 0.42;
  pointer-events: none;
}

.switch {
  position: relative;
  width: 40px;
  height: 22px;
  border-radius: 999px;
  border: 0;
  background: rgba(255, 255, 255, 0.13);
  cursor: pointer;
  transition: background 0.18s;
}

.switch span {
  position: absolute;
  top: 3px;
  left: 3px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: #cfd6c8;
  transition: left 0.18s, background 0.18s;
}

.switch.is-on {
  background: var(--olive);
}

.switch.is-on span {
  left: 21px;
  background: #131708;
}

.history-pager {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.history-pager button {
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
  font-size: 12px;
  line-height: 1;
  padding: 5px 9px;
  border-radius: 7px;
  cursor: pointer;
  transition: background 0.16s, border-color 0.16s;
}

.history-pager button:hover:not(:disabled) {
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--line-strong);
}

.history-pager button:focus-visible {
  outline: 2px solid var(--olive);
  outline-offset: 2px;
}

.history-pager button:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

.pager-label {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--dim);
  letter-spacing: 0.02em;
}

.moves {
  flex: 1 1 auto;
  min-height: 48px;
  overflow-y: auto;
  overflow-x: hidden;
  scrollbar-width: thin;
  scrollbar-color: rgba(255, 255, 255, 0.14) transparent;
  padding-right: 2px;
}

.moves::-webkit-scrollbar {
  width: 6px;
}

.moves::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.12);
  border-radius: 3px;
}

.moves-empty {
  margin: 10px 0;
  color: var(--dim);
  font-size: 12px;
  text-align: center;
}

.move-row {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr) minmax(0, 1fr);
  align-items: center;
  gap: 4px;
  padding: 3px 7px;
  border-radius: 6px;
  font-family: var(--mono);
  font-size: 12.5px;
}

.move-row:nth-child(odd) {
  background: rgba(255, 255, 255, 0.026);
}

.move-no {
  color: var(--dim);
  font-size: 11px;
}

.move-san {
  color: #cfd6c9;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.move-row.is-last .move-san:last-child,
.move-row.is-last .move-san:nth-child(2):last-child {
  color: var(--olive);
}

:root[data-theme="melon"] {
  --olive: #fc0377;
  --olive-soft: rgba(252, 3, 119, 0.2);
}

:root[data-theme="melon"] .btn-primary {
  color: #fff;
  box-shadow: 0 16px 34px -14px rgba(252, 3, 119, 0.7);
}

:root[data-theme="melon"] .btn-primary:hover {
  background: #ff3d95;
}

:root[data-theme="melon"] .sq.hint::before {
  background: rgba(252, 3, 119, 0.16);
  box-shadow: 0 0 0 3px rgba(252, 3, 119, 0.85) inset;
}

:root[data-theme="melon"] .sq.kbfocus::before {
  box-shadow: 0 0 0 3px rgba(252, 3, 119, 0.9) inset;
}

.modal {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: grid;
  place-items: center;
  padding: 20px;
  overscroll-behavior: contain;
  background: rgba(5, 7, 6, 0.72);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  animation: fadeIn 0.16s ease both;
}

.modal-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  padding: 22px 24px 18px;
  border-radius: 20px;
  border: 1px solid var(--line-strong);
  background: linear-gradient(180deg, #1d231e, #10140f);
  box-shadow: 0 30px 70px -30px #000;
}

.modal-card:focus {
  outline: none;
}

.drawer {
  place-items: start end;
  padding: 16px;
}

.drawer-card {
  width: min(400px, 100%);
  height: auto;
  max-height: 100%;
  align-items: stretch;
  gap: 10px;
  padding: 18px 18px 16px;
}

.drawer-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

#historyClose {
  padding: 5px 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
}

#historyClose:hover {
  border-color: var(--line-strong);
  color: var(--text);
}

.promo-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}

.promo-btn.piece {
  width: 64px;
  height: 64px;
  padding: 8px;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.05);
  cursor: pointer;
  transition: background 0.16s, border-color 0.16s;
}

.promo-btn.piece:hover {
  background: rgba(154, 219, 55, 0.12);
  border-color: rgba(154, 219, 55, 0.5);
}

.promo-btn.piece svg {
  filter: none;
}

.toast {
  position: fixed;
  left: 50%;
  bottom: 20px;
  z-index: 120;
  transform: translate(-50%, 12px);
  padding: 10px 18px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  background: rgba(22, 27, 23, 0.96);
  color: var(--text);
  font-size: 12px;
  letter-spacing: 0.03em;
  width: max-content;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease, transform 0.2s ease;
  box-shadow: 0 16px 40px -18px #000;
  max-width: calc(100vw - 32px);
  text-align: center;
}

.toast.is-visible {
  opacity: 1;
  transform: translate(-50%, 0);
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes pieceIn {
  from {
    transform: scale(0.84);
    opacity: 0.3;
  }
  to {
    transform: scale(1);
    opacity: 1;
  }
}

@keyframes hintPulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.55; }
}

@keyframes checkPulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}

@media (max-width: 980px) {
  .shell {
    padding-bottom: 72px;
  }

  .promo-btn.piece {
    width: 56px;
    height: 56px;
  }
}

@media (max-width: 980px) and (orientation: portrait) {
  .toast {
    bottom: 84px;
  }
}

@media (max-width: 560px) {
  .shell {
    padding: 18px 12px 72px;
  }

  .topbar {
    margin-bottom: 16px;
  }

  h1 {
    font-size: 25px;
  }

  .brand-mark {
    width: 25px;
    height: 25px;
  }

  .nav-btn {
    min-height: 40px;
    padding: 8px 10px;
  }

  .board-frame {
    padding: 6px;
    border-radius: 15px;
  }

  .board,
  .board::after {
    border-radius: 10px;
  }

  .player-strip {
    gap: 8px;
    padding: 7px 2px;
  }

  .coord {
    font-size: 8px;
  }

  .coord-rank {
    top: 2px;
    left: 3px;
  }

  .coord-file {
    right: 3px;
    bottom: 2px;
  }

  .drawer {
    place-items: end stretch;
    padding: 0;
  }

  .drawer-card {
    width: 100%;
    height: auto;
    max-height: 86vh;
    border-radius: 20px 20px 0 0;
  }

  .drawer .moves {
    max-height: calc(86vh - 124px);
  }

  .promo-btn.piece {
    width: 56px;
    height: 56px;
  }

  .result-card {
    padding: 24px 28px;
  }

  .result-card h2 {
    font-size: 25px;
  }
}

@media (max-width: 380px) {
  .brand-mark,
  .nav-count {
    display: none;
  }

  h1 {
    font-size: 22px;
  }

  .capture-piece.piece {
    width: 15px;
    height: 15px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001s !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001s !important;
  }
}