:root {
  --bg: #0f172a;
  --surface: #1e293b;
  --surface-hover: #273549;
  --line: rgba(148, 163, 184, 0.18);
  --text: #e2e8f0;
  --muted: #94a3b8;
  --accent: #c084fc;
  --accent-strong: #d8b4fe;
  --accent-ink: #1f0b36;
  --accent-soft: rgba(192, 132, 252, 0.16);
  --radius: 12px;
  --shadow: 0 14px 34px -18px rgba(2, 6, 23, 0.9), 0 2px 8px rgba(2, 6, 23, 0.35);
  --fast: 150ms;
  --mid: 220ms;
  --move: 240ms;
  --ivory: #f1e8d8;
  --ebony: #2b2521;
  --wood-light: #ddb47c;
  --wood-dark: #ad7741;
  --ink: #3a2312;
  color-scheme: dark;
}

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

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

body {
  margin: 0;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  background:
    radial-gradient(900px 480px at 50% -12%, rgba(192, 132, 252, 0.14), transparent 70%),
    var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  font-size: 15px;
  line-height: 1.45;
}

h1,
h2,
h3,
p {
  margin: 0;
}

/* ---------- header and footer ---------- */

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 12px 16px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
}

.brand h1 {
  font-size: 20px;
  font-weight: 800;
  letter-spacing: 0.01em;
  white-space: nowrap;
}

.brand-mark {
  width: 32px;
  height: 32px;
  flex: none;
}

.brand-tile {
  fill: var(--surface);
  stroke: var(--line);
}

.brand-lines {
  fill: none;
  stroke: var(--accent);
  stroke-width: 1.6;
  stroke-linecap: round;
}

.brand-white {
  fill: var(--ivory);
}

.brand-black {
  fill: var(--ebony);
  stroke: var(--accent);
  stroke-width: 0.9;
}

.topbar-actions {
  display: flex;
  gap: 8px;
  flex: none;
}

.footer {
  padding: 10px 16px 14px;
  text-align: center;
  color: var(--muted);
  font-size: 13px;
}

.footer a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  color: var(--accent);
  text-decoration: none;
}

.footer a:hover,
.footer a:focus-visible {
  text-decoration: underline;
}

/* ---------- buttons ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text);
  font: inherit;
  font-weight: 650;
  cursor: pointer;
  transition: background-color var(--fast), border-color var(--fast), color var(--fast), transform var(--fast), opacity var(--fast);
}

.btn:hover {
  background: var(--surface-hover);
  border-color: rgba(192, 132, 252, 0.45);
}

.btn:active {
  transform: translateY(1px);
}

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

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  transform: none;
  border-color: var(--line);
  background: var(--surface);
}

.btn-primary {
  background: var(--accent);
  border-color: transparent;
  color: var(--accent-ink);
  box-shadow: 0 8px 22px -12px rgba(192, 132, 252, 0.9);
}

.btn-primary:hover {
  background: var(--accent-strong);
  border-color: transparent;
}

.btn-lang {
  min-width: 48px;
  padding: 0 12px;
  letter-spacing: 0.04em;
}

.btn svg {
  width: 18px;
  height: 18px;
  flex: none;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* ---------- layout ---------- */

/* Phones: status, board and panel stacked. Wide screens: board left, panel
   right. Landscape phones: the board takes the full height on the left. */
.layout {
  flex: 1;
  display: grid;
  grid-template-columns: minmax(0, 560px);
  grid-template-areas: "status" "board" "panel";
  justify-content: center;
  align-content: start;
  gap: 12px 28px;
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 4px 16px 8px;
}

.status {
  grid-area: status;
}

.board-wrap {
  grid-area: board;
}

.panel {
  grid-area: panel;
  display: flex;
  flex-direction: column;
  gap: 14px;
  min-width: 0;
  padding-top: 2px;
}

@media (min-width: 860px) {
  .layout {
    --board: min(calc(100vh - 190px), 720px, calc(100vw - 400px));
    grid-template-columns: var(--board) 300px;
    grid-template-rows: auto 1fr;
    grid-template-areas: "status panel" "board panel";
    align-items: start;
    padding-top: 8px;
  }
}

@media (orientation: landscape) and (max-height: 540px) and (min-width: 560px) {
  .topbar {
    padding-block: 6px;
  }

  .layout {
    --board: calc(100vh - 72px);
    grid-template-columns: var(--board) minmax(0, 300px);
    grid-template-rows: auto 1fr;
    grid-template-areas: "board status" "board panel";
    align-items: start;
    gap: 10px 20px;
  }

  .keys {
    display: none;
  }
}

@supports (height: 100dvh) {
  @media (orientation: landscape) and (max-height: 540px) and (min-width: 560px) {
    .layout {
      --board: calc(100dvh - 72px);
    }
  }
}

/* ---------- status line ---------- */

.status {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 54px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
  transition: border-color var(--mid), background-color var(--mid);
}

.status[data-tone="mill"] {
  border-color: rgba(192, 132, 252, 0.75);
  background: linear-gradient(90deg, rgba(192, 132, 252, 0.2), rgba(192, 132, 252, 0.05)), var(--surface);
}

.status[data-tone="over"] {
  border-color: rgba(192, 132, 252, 0.5);
}

.status-text {
  flex: 1;
  min-width: 0;
  line-height: 1.3;
}

.status-text strong {
  font-weight: 750;
}

.status:not([data-tone="over"]) .status-text strong::after {
  content: " ·";
  color: var(--muted);
  font-weight: 400;
}

.status[data-tone="mill"] #status-action {
  color: var(--accent-strong);
  font-weight: 650;
}

.status[data-tone="hint"] #status-action {
  color: #fcd34d;
}

.status-disc,
.disc {
  display: inline-block;
  flex: none;
  border-radius: 50%;
}

.status-disc {
  width: 20px;
  height: 20px;
}

.is-white,
.disc--white {
  background: radial-gradient(circle at 38% 32%, #fffdf8, var(--ivory) 55%, #c3ad86);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.45);
}

.is-black,
.disc--black {
  background: radial-gradient(circle at 38% 32%, #716760, var(--ebony) 50%, #0b0908);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.45), inset 0 0 0 1px rgba(226, 232, 240, 0.22);
}

.status-disc.is-draw {
  background: linear-gradient(90deg, var(--ivory) 50%, var(--ebony) 50%);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.45), inset 0 0 0 1px rgba(226, 232, 240, 0.22);
}

.status[data-tone="thinking"] .status-disc {
  animation: pulse 1s ease-in-out infinite;
}

.phase-chip {
  flex: none;
  padding: 4px 9px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-size: 12px;
  font-weight: 750;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

/* ---------- board ---------- */

.board-wrap {
  position: relative;
  width: 100%;
  aspect-ratio: 1;
  border-radius: var(--radius);
  background:
    radial-gradient(120% 90% at 22% 12%, rgba(255, 236, 200, 0.4), transparent 62%),
    repeating-linear-gradient(97deg, rgba(110, 62, 24, 0.08) 0 2px, transparent 2px 7px, rgba(110, 62, 24, 0.05) 7px 9px, transparent 9px 17px),
    repeating-linear-gradient(83deg, rgba(255, 246, 228, 0.06) 0 1px, transparent 1px 23px),
    linear-gradient(135deg, var(--wood-light), var(--wood-dark));
  box-shadow:
    var(--shadow),
    0 26px 50px -28px rgba(0, 0, 0, 0.9),
    inset 0 0 0 1px rgba(255, 240, 215, 0.3),
    inset 0 -14px 34px rgba(76, 40, 12, 0.28);
}

.board {
  display: block;
  width: 100%;
  height: 100%;
  overflow: visible;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
  -webkit-tap-highlight-color: transparent;
}

.board .frame {
  fill: none;
  stroke: rgba(58, 35, 18, 0.35);
  stroke-width: 3;
}

.board .motif {
  fill: none;
  stroke: var(--ink);
  stroke-width: 3;
  opacity: 0.3;
}

.board .motif path {
  fill: rgba(192, 132, 252, 0.55);
  stroke: rgba(58, 35, 18, 0.8);
}

.board .lines path {
  fill: none;
  stroke: var(--ink);
  stroke-width: 7;
  stroke-linecap: round;
  opacity: 0.9;
}

.board .dots circle {
  fill: var(--ink);
}

.board .dots .dot-core {
  fill: rgba(255, 228, 186, 0.4);
}

.mill-line {
  fill: none;
  stroke: var(--accent);
  stroke-width: 18;
  stroke-linecap: round;
  opacity: 0;
  transition: opacity var(--mid);
}

.mill-line.is-closed {
  opacity: 0.4;
}

.mill-line.is-fresh {
  opacity: 0.9;
  stroke-dasharray: 1 1;
  animation: draw-mill 250ms ease-out both;
}

/* Pieces */

.piece {
  transition: transform var(--move) cubic-bezier(0.2, 0.8, 0.2, 1);
}

.piece.is-dragging {
  transition: none;
}

.piece-body {
  transition: transform var(--fast) ease-out;
}

.piece-shadow {
  fill: url(#piece-shadow);
}

.piece--white .disc {
  fill: url(#piece-white);
  stroke: #9d8a69;
  stroke-width: 1.5;
}

.piece--black .disc {
  fill: url(#piece-black);
  stroke: #050403;
  stroke-width: 1.5;
}

.piece .inlay {
  fill: none;
  stroke-width: 2.5;
}

.piece--white .inlay {
  stroke: rgba(122, 94, 56, 0.3);
}

.piece--black .inlay {
  stroke: rgba(255, 255, 255, 0.13);
}

.piece.is-selected .piece-body,
.piece.is-dragging .piece-body {
  transform: scale(1.1);
}

.piece.is-entering .piece-body {
  animation: piece-in 240ms cubic-bezier(0.2, 0.9, 0.3, 1.25) both;
}

.piece.is-leaving .piece-body {
  animation: piece-out 250ms ease-in forwards;
}

.piece.is-leaving.is-delayed .piece-body {
  animation-delay: 220ms;
}

/* Spots: hit areas and highlights above the pieces */

.spot {
  outline: none;
}

.spot .hit {
  fill: transparent;
}

.spot .ghost,
.spot .target,
.spot .trail,
.spot .ring,
.spot .focus {
  pointer-events: none;
}

.spot .ghost {
  opacity: 0;
  transition: opacity var(--fast);
}

.board[data-turn="white"] .ghost {
  fill: url(#piece-white);
}

.board[data-turn="black"] .ghost {
  fill: url(#piece-black);
}

.spot .target {
  fill: var(--accent);
  stroke: rgba(31, 11, 54, 0.55);
  stroke-width: 3;
  opacity: 0;
  transform: scale(0.4);
  transition: opacity var(--fast), transform var(--fast);
}

.spot.is-target .target {
  opacity: 0.95;
  transform: scale(1);
}

.board[data-phase="placing"] .spot.is-target .target {
  opacity: 0.5;
  transform: scale(0.62);
}

.spot.is-target.is-drop .target {
  opacity: 1;
  transform: scale(1.6);
}

.spot .trail {
  fill: none;
  stroke: var(--ink);
  stroke-width: 3;
  stroke-dasharray: 6 7;
  opacity: 0;
}

.spot.is-trail .trail {
  opacity: 0.6;
}

.spot .ring {
  fill: none;
  stroke: var(--accent);
  stroke-width: 5;
  opacity: 0;
  transition: opacity var(--fast), stroke-width var(--fast);
}

.spot.is-movable .ring {
  opacity: 0.45;
}

.spot.is-selected .ring {
  opacity: 1;
  stroke-width: 6;
}

.spot.is-removable .ring {
  opacity: 1;
  stroke-width: 6;
  stroke-dasharray: 14 9;
  animation: spin 7s linear infinite;
}

.spot .focus {
  fill: none;
  stroke: #2e1065;
  stroke-width: 5;
  opacity: 0;
}

.spot:focus-visible .focus {
  opacity: 1;
}

.spot.is-target,
.spot.is-movable,
.spot.is-removable {
  cursor: pointer;
}

.board.is-busy .spot {
  cursor: progress;
}

@media (hover: hover) {
  .spot.is-target:hover .ghost {
    opacity: 0.5;
  }

  .spot.is-movable:hover .ring {
    opacity: 0.85;
  }

  .spot.is-removable:hover .ring {
    stroke-width: 8;
  }
}

/* Result card over the board */

.result {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 16px;
  border-radius: inherit;
  background: rgba(15, 23, 42, 0.5);
  backdrop-filter: blur(2px);
  animation: fade-in var(--mid) ease-out;
}

.result[hidden] {
  display: none;
}

.result-card {
  max-width: 300px;
  padding: 22px 24px;
  border: 1px solid rgba(192, 132, 252, 0.55);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow), 0 0 0 6px rgba(192, 132, 252, 0.08);
  text-align: center;
}

.result-title {
  margin-bottom: 6px;
  font-size: 24px;
  font-weight: 800;
}

.result-reason {
  margin-bottom: 18px;
  color: var(--muted);
}

/* ---------- players ---------- */

.players {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  padding-top: 6px;
}

.player {
  position: relative;
  min-width: 0;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
  transition: border-color var(--mid), box-shadow var(--mid);
}

.player.is-active {
  border-color: rgba(192, 132, 252, 0.7);
  box-shadow: var(--shadow), 0 0 0 3px var(--accent-soft);
}

.player.is-winner {
  border-color: var(--accent);
}

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

.player-head .disc {
  width: 18px;
  height: 18px;
}

.player-name {
  font-size: 15px;
  font-weight: 750;
}

/* "You" / "Computer" sits on the top edge of the card, so long names never crowd it. */
.player-role {
  position: absolute;
  top: 0;
  right: 10px;
  max-width: calc(100% - 20px);
  overflow: hidden;
  padding: 1px 8px;
  border: 1px solid rgba(148, 163, 184, 0.3);
  border-radius: 999px;
  background: var(--surface);
  color: var(--muted);
  font-size: 12px;
  font-weight: 750;
  letter-spacing: 0.06em;
  line-height: 1.5;
  text-overflow: ellipsis;
  text-transform: uppercase;
  white-space: nowrap;
  transform: translateY(-50%);
  transition: border-color var(--mid), color var(--mid);
}

.player.is-active .player-role {
  border-color: rgba(192, 132, 252, 0.7);
  color: var(--accent-strong);
}

.player-role:empty {
  display: none;
}

.tally {
  display: flex;
  flex-wrap: wrap;
  gap: 3px;
  margin: 9px 0 7px;
}

.tally i {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  transition: background-color var(--mid), box-shadow var(--mid), opacity var(--mid);
}

.player--white .tally .is-board {
  background: radial-gradient(circle at 38% 32%, #fffdf8, var(--ivory) 60%, #c3ad86);
}

.player--black .tally .is-board {
  background: radial-gradient(circle at 38% 32%, #8a7f77, var(--ebony) 60%, #0b0908);
  box-shadow: inset 0 0 0 1px rgba(226, 232, 240, 0.4);
}

.tally .is-hand {
  box-shadow: inset 0 0 0 1.5px var(--muted);
}

.tally .is-lost {
  box-shadow: inset 0 0 0 1px rgba(148, 163, 184, 0.3);
  opacity: 0.35;
  transform: scale(0.6);
}

.player-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 2px 12px;
  margin: 0;
  color: var(--muted);
  font-size: 12.5px;
}

.player-stats div {
  display: flex;
  align-items: baseline;
  gap: 5px;
}

.player-stats dd {
  margin: 0;
  color: var(--text);
  font-weight: 750;
  font-variant-numeric: tabular-nums;
}

/* ---------- actions and settings ---------- */

.actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.settings {
  display: grid;
  gap: 12px;
}

.seg-group {
  min-width: 0;
  margin: 0;
  padding: 0;
  border: 0;
  transition: opacity var(--mid);
}

.seg-group:disabled {
  opacity: 0.4;
}

.seg-group legend {
  margin-bottom: 6px;
  padding: 0;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.seg {
  display: flex;
  gap: 3px;
  padding: 3px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.seg label {
  position: relative;
  flex: 1;
  min-width: 0;
}

.seg input {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  margin: 0;
  opacity: 0;
  cursor: pointer;
}

.seg-group:disabled input {
  cursor: not-allowed;
}

.seg input + span {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  min-height: 40px;
  padding: 0 6px;
  border-radius: calc(var(--radius) - 4px);
  color: var(--muted);
  font-size: 14px;
  font-weight: 650;
  text-align: center;
  line-height: 1.15;
  transition: background-color var(--fast), color var(--fast);
}

.seg input + span .disc {
  width: 14px;
  height: 14px;
}

.seg input:hover + span {
  color: var(--text);
}

.seg input:checked + span {
  background: var(--accent);
  color: var(--accent-ink);
}

.seg input:focus-visible + span {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.keys {
  color: var(--muted);
  font-size: 12.5px;
}

@media (hover: none) {
  .keys {
    display: none;
  }
}

/* ---------- rules dialog ---------- */

.dialog {
  width: min(560px, calc(100% - 32px));
  max-height: calc(100% - 48px);
  padding: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text);
  box-shadow: 0 30px 80px -24px rgba(0, 0, 0, 0.85);
}

.dialog[open] {
  animation: fade-in var(--mid) ease-out;
}

.dialog::backdrop {
  background: rgba(2, 6, 23, 0.7);
}

.dialog-inner {
  padding: 20px 22px;
}

.dialog h2 {
  margin-bottom: 12px;
  font-size: 20px;
}

/* The title takes the focus on opening so the rules start at the top; it is not a control, so no ring. */
.dialog h2:focus {
  outline: none;
}

.dialog h3 {
  margin-bottom: 8px;
  font-size: 16px;
}

.rules-list {
  display: grid;
  gap: 8px;
  margin: 0 0 18px;
  padding-left: 22px;
  color: #cbd5e1;
}

.rules-list li::marker {
  color: var(--accent);
  font-weight: 700;
}

.dialog-actions {
  display: flex;
  justify-content: flex-end;
}

/* ---------- animations ---------- */

@keyframes piece-in {
  from {
    opacity: 0;
    transform: translateY(-26px) scale(1.25);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

@keyframes piece-out {
  to {
    opacity: 0;
    transform: scale(0.3);
  }
}

@keyframes draw-mill {
  from {
    stroke-dashoffset: 1;
  }
  to {
    stroke-dashoffset: 0;
  }
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@keyframes pulse {
  50% {
    transform: scale(0.75);
    opacity: 0.6;
  }
}

@keyframes fade-in {
  from {
    opacity: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 1ms !important;
    animation-delay: 0ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 1ms !important;
  }
}