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

:root {
  --wood-dark: #5c3d2e;
  --wood-mid: #8b6914;
  --wood-light: #c4a35a;
  --wood-highlight: #c4b5fd;
  --line: rgba(160, 195, 255, 0.22);
  --ink: #1a120c;
  --paper: #f6f0e6;
  --black-stone: #1c1c1e;
  --white-stone: #f5f5f5;
  --accent: #6366f1;
  --danger: #9b2226;
  --radius: 12px;
  --shadow-board:
    0 8px 32px rgba(0, 0, 0, 0.55),
    0 0 0 1px rgba(120, 160, 255, 0.12),
    inset 0 0 40px rgba(80, 60, 140, 0.2);
}

html {
  font-size: 16px;
}

body {
  margin: 0;
  min-height: 100vh;
  position: relative;
  isolation: isolate;
  font-family: "Segoe UI", "PingFang TC", "Microsoft JhengHei", sans-serif;
  color: var(--ink);
  background: #030510;
  overflow-x: hidden;
}

/* 銀河動畫底層：緩慢漂移的星雲 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
  background:
    radial-gradient(ellipse 85% 70% at 25% 40%, rgba(120, 80, 200, 0.5), transparent 58%),
    radial-gradient(ellipse 75% 65% at 78% 58%, rgba(45, 110, 220, 0.4), transparent 52%),
    radial-gradient(ellipse 55% 45% at 52% 88%, rgba(160, 90, 190, 0.22), transparent 55%),
    radial-gradient(ellipse 100% 90% at 48% -5%, rgba(99, 102, 241, 0.28), transparent 48%),
    radial-gradient(ellipse 60% 50% at 8% 75%, rgba(56, 189, 248, 0.12), transparent 50%);
  background-size: 140% 140%;
  background-repeat: no-repeat;
  animation: galaxy-nebula 5s ease-in-out infinite alternate;
}

/* 星點層：微移動＋明暗閃爍 */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    radial-gradient(1.2px 1.2px at 8% 12%, rgba(255, 255, 255, 0.95), transparent),
    radial-gradient(1px 1px at 92% 8%, rgba(255, 255, 255, 0.8), transparent),
    radial-gradient(1px 1px at 18% 78%, rgba(200, 220, 255, 0.75), transparent),
    radial-gradient(1.5px 1.5px at 45% 22%, rgba(255, 250, 220, 0.9), transparent),
    radial-gradient(1px 1px at 72% 65%, rgba(255, 255, 255, 0.65), transparent),
    radial-gradient(1px 1px at 35% 45%, rgba(255, 255, 255, 0.5), transparent),
    radial-gradient(1px 1px at 88% 42%, rgba(255, 255, 255, 0.55), transparent),
    radial-gradient(2px 2px at 55% 88%, rgba(255, 255, 255, 0.4), transparent),
    radial-gradient(1px 1px at 12% 55%, rgba(180, 200, 255, 0.6), transparent),
    radial-gradient(1px 1px at 62% 12%, rgba(255, 255, 255, 0.45), transparent),
    radial-gradient(1px 1px at 28% 92%, rgba(255, 255, 255, 0.5), transparent),
    radial-gradient(1px 1px at 95% 88%, rgba(255, 255, 255, 0.35), transparent),
    radial-gradient(1px 1px at 50% 50%, rgba(255, 255, 255, 0.25), transparent),
    radial-gradient(1px 1px at 5% 35%, rgba(255, 255, 255, 0.4), transparent),
    radial-gradient(1px 1px at 40% 8%, rgba(220, 230, 255, 0.7), transparent);
  background-size: 115% 115%;
  background-repeat: no-repeat;
  animation:
    galaxy-stars-shift 5s linear infinite,
    galaxy-stars-twinkle 5s ease-in-out infinite alternate;
}

@keyframes galaxy-nebula {
  0% {
    transform: scale(1) translate(0%, 0%) rotate(0deg);
    background-position:
      12% 35%,
      82% 62%,
      48% 92%,
      50% 5%,
      10% 78%;
  }
  33% {
    transform: scale(1.05) translate(2%, -1.5%) rotate(1.2deg);
    background-position:
      35% 55%,
      65% 45%,
      55% 85%,
      35% 18%,
      22% 65%;
  }
  66% {
    transform: scale(1.08) translate(-1.5%, 2%) rotate(-0.8deg);
    background-position:
      55% 28%,
      40% 70%,
      45% 95%,
      62% 12%,
      8% 50%;
  }
  100% {
    transform: scale(1.02) translate(1%, 1%) rotate(0.5deg);
    background-position:
      70% 48%,
      30% 52%,
      52% 88%,
      48% 22%,
      15% 82%;
  }
}

@keyframes galaxy-stars-shift {
  0% {
    background-position:
      0% 0%,
      100% 0%,
      0% 100%,
      50% 20%,
      80% 60%,
      30% 40%,
      90% 35%,
      55% 90%,
      10% 50%,
      60% 10%,
      25% 95%,
      95% 85%,
      50% 50%,
      5% 30%,
      40% 5%;
  }
  100% {
    background-position:
      3% 2%,
      97% 2%,
      2% 97%,
      53% 22%,
      77% 58%,
      33% 43%,
      87% 38%,
      58% 88%,
      13% 52%,
      63% 13%,
      28% 92%,
      92% 82%,
      52% 48%,
      8% 33%,
      43% 8%;
  }
}

@keyframes galaxy-stars-twinkle {
  from {
    opacity: 0.72;
    filter: brightness(0.92);
  }
  to {
    opacity: 1;
    filter: brightness(1.12);
  }
}

@media (prefers-reduced-motion: reduce) {
  body::before,
  body::after {
    animation: none;
  }

  body::before {
    transform: none;
    background-position:
      12% 35%,
      82% 62%,
      48% 92%,
      50% 5%,
      10% 78%;
  }

  body::after {
    opacity: 0.88;
    background-position:
      0% 0%,
      100% 0%,
      0% 100%,
      50% 20%,
      80% 60%,
      30% 40%,
      90% 35%,
      55% 90%,
      10% 50%,
      60% 10%,
      25% 95%,
      95% 85%,
      50% 50%,
      5% 30%,
      40% 8%;
  }
}

.app {
  max-width: 720px;
  margin: 0 auto;
  padding: 1.25rem 1rem 2rem;
}

.header {
  text-align: center;
  margin-bottom: 1rem;
}

.header h1 {
  margin: 0;
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--paper);
  letter-spacing: 0.08em;
}

.subtitle {
  margin: 0.35rem 0 0;
  font-size: 0.9rem;
  color: rgba(246, 240, 230, 0.75);
}

/* --- Toolbar --- */
.toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem 1rem;
  padding: 0.85rem 1rem;
  background: rgba(246, 240, 230, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius);
  margin-bottom: 0.75rem;
}

.field {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.field-label {
  font-size: 0.85rem;
  color: rgba(246, 240, 230, 0.9);
}

select {
  padding: 0.4rem 2rem 0.4rem 0.6rem;
  border-radius: 8px;
  border: 1px solid rgba(0, 0, 0, 0.2);
  background: var(--paper);
  color: var(--ink);
  font-size: 0.9rem;
  cursor: pointer;
}

.hint {
  flex-basis: 100%;
  font-size: 0.75rem;
  color: rgba(246, 240, 230, 0.55);
}

.btn {
  padding: 0.45rem 1rem;
  border-radius: 8px;
  border: none;
  font-size: 0.9rem;
  cursor: pointer;
  font-weight: 600;
  transition: transform 0.08s ease, filter 0.15s ease;
}

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

.btn.primary {
  background: linear-gradient(180deg, #40916c, var(--accent));
  color: #fff;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.25);
}

.btn.primary:hover {
  filter: brightness(1.06);
}

.btn.ghost {
  background: transparent;
  color: rgba(246, 240, 230, 0.85);
  border: 1px solid rgba(255, 255, 255, 0.25);
}

.btn.ghost:hover {
  background: rgba(255, 255, 255, 0.08);
}

/* --- Status --- */
.status-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 1.75rem;
  margin-bottom: 0.75rem;
  padding: 0 0.25rem;
}

.turn-label {
  font-size: 0.95rem;
  color: var(--paper);
  font-weight: 600;
}

.think-label {
  font-size: 0.85rem;
  color: rgba(232, 212, 168, 0.95);
  font-style: italic;
}

.think-label.hidden {
  display: none;
}

/* --- Stats --- */
.stats {
  margin-bottom: 1rem;
}

.stats-title {
  margin: 0 0 0.5rem;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: rgba(246, 240, 230, 0.55);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 0.5rem;
}

.stat-card {
  background: rgba(246, 240, 230, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 10px;
  padding: 0.5rem 0.65rem;
  font-size: 0.8rem;
  color: rgba(246, 240, 230, 0.92);
}

.stat-card strong {
  display: block;
  margin-bottom: 0.25rem;
  color: var(--wood-highlight);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
}

/* --- Board --- */
.board-wrap {
  display: flex;
  justify-content: center;
  padding: 0.5rem 0;
}

.board {
  position: relative;
  display: grid;
  grid-template-columns: repeat(10, 1fr);
  grid-template-rows: repeat(10, 1fr);
  width: min(92vw, 480px);
  aspect-ratio: 1;
  padding: 4%;
  border-radius: 10px;
  box-shadow: var(--shadow-board);
  background-color: #0a0e1f;
  /* 銀河：星點＋星雲＋深空底 */
  background-image:
    radial-gradient(1.2px 1.2px at 12% 18%, rgba(255, 255, 255, 0.95), transparent),
    radial-gradient(1px 1px at 88% 12%, rgba(255, 255, 255, 0.75), transparent),
    radial-gradient(1px 1px at 42% 8%, rgba(200, 220, 255, 0.85), transparent),
    radial-gradient(1px 1px at 76% 88%, rgba(255, 255, 255, 0.65), transparent),
    radial-gradient(1px 1px at 22% 72%, rgba(255, 255, 255, 0.5), transparent),
    radial-gradient(1px 1px at 92% 48%, rgba(255, 255, 255, 0.55), transparent),
    radial-gradient(1.6px 1.6px at 55% 42%, rgba(255, 245, 210, 0.9), transparent),
    radial-gradient(1px 1px at 6% 55%, rgba(255, 255, 255, 0.45), transparent),
    radial-gradient(1px 1px at 35% 38%, rgba(255, 255, 255, 0.4), transparent),
    radial-gradient(2px 2px at 65% 28%, rgba(255, 255, 255, 0.35), transparent),
    radial-gradient(1px 1px at 48% 92%, rgba(180, 200, 255, 0.5), transparent),
    radial-gradient(1px 1px at 82% 72%, rgba(255, 255, 255, 0.4), transparent),
    radial-gradient(ellipse 90% 60% at 22% 38%, rgba(120, 70, 180, 0.38), transparent 58%),
    radial-gradient(ellipse 75% 50% at 82% 58%, rgba(40, 100, 200, 0.32), transparent 52%),
    radial-gradient(ellipse 60% 45% at 50% 85%, rgba(160, 80, 160, 0.15), transparent 55%),
    radial-gradient(ellipse 50% 35% at 58% 18%, rgba(56, 189, 248, 0.12), transparent 50%),
    linear-gradient(155deg, #060a16 0%, #121c3d 38%, #0a0f24 100%);
}

.board::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 10px;
  pointer-events: none;
  box-shadow:
    inset 0 0 0 2px rgba(100, 140, 220, 0.25),
    inset 0 0 24px rgba(60, 40, 120, 0.35),
    inset 0 2px 20px rgba(255, 255, 255, 0.04);
}

.board::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 10px;
  pointer-events: none;
  opacity: 0.22;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.55'/%3E%3C/svg%3E");
  mix-blend-mode: soft-light;
}

.cell {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  border: 0;
  padding: 0;
  margin: 0;
  appearance: none;
  background: transparent;
  box-shadow:
    inset 0 -1px 0 var(--line),
    inset -1px 0 0 var(--line);
}

.board .cell:nth-child(10n + 1) {
  box-shadow:
    inset 0 -1px 0 var(--line),
    inset -1px 0 0 var(--line),
    inset 2px 0 0 rgba(130, 170, 255, 0.35);
}

.board .cell:nth-child(-n + 10) {
  box-shadow:
    inset 0 -1px 0 var(--line),
    inset -1px 0 0 var(--line),
    inset 0 2px 0 rgba(130, 170, 255, 0.35);
}

.board .cell:nth-child(10n + 1):nth-child(-n + 10) {
  box-shadow:
    inset 0 -1px 0 var(--line),
    inset -1px 0 0 var(--line),
    inset 2px 0 0 rgba(130, 170, 255, 0.35),
    inset 0 2px 0 rgba(130, 170, 255, 0.35);
}

.board .cell:nth-child(10n) {
  box-shadow:
    inset 0 -1px 0 var(--line),
    inset -1px 0 0 var(--line),
    inset -2px 0 0 rgba(130, 170, 255, 0.28);
}

.board .cell:nth-child(n + 91) {
  box-shadow:
    inset 0 -1px 0 var(--line),
    inset -1px 0 0 var(--line),
    inset 0 -2px 0 rgba(130, 170, 255, 0.28);
}

.board .cell:nth-child(10n):nth-child(n + 91) {
  box-shadow:
    inset 0 -1px 0 var(--line),
    inset -1px 0 0 var(--line),
    inset -2px 0 0 rgba(130, 170, 255, 0.28),
    inset 0 -2px 0 rgba(130, 170, 255, 0.28);
}

.cell:hover:not(.disabled)::after {
  content: "";
  position: absolute;
  width: 28%;
  height: 28%;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.14);
  pointer-events: none;
}

.cell.disabled {
  cursor: default;
}

.cell .stone {
  width: 72%;
  height: 72%;
  border-radius: 50%;
  position: relative;
  z-index: 2;
  animation: drop 0.22s ease-out;
}

/* 黑棋：星星（深空底＋五角星） */
.cell .stone.black {
  background-color: #1a1535;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'%3E%3Cdefs%3E%3CradialGradient id='g' cx='35%25' cy='28%25' r='72%25'%3E%3Cstop offset='0%25' stop-color='%235c5890'/%3E%3Cstop offset='55%25' stop-color='%23252045'/%3E%3Cstop offset='100%25' stop-color='%230c0820'/%3E%3C/radialGradient%3E%3CradialGradient id='sg' cx='40%25' cy='35%25' r='55%25'%3E%3Cstop offset='0%25' stop-color='%23fffef5'/%3E%3Cstop offset='100%25' stop-color='%23ffd966'/%3E%3C/radialGradient%3E%3C/defs%3E%3Ccircle cx='50' cy='50' r='48' fill='url(%23g)'/%3E%3Cpath fill='url(%23sg)' stroke='%23b8860b' stroke-width='0.9' stroke-linejoin='round' d='M50 12L61 38L88 38L66 54L76 82L50 66L24 82L34 54L12 38L39 38z'/%3E%3C/svg%3E");
  background-size: cover;
  background-position: center;
  box-shadow:
    0 2px 8px rgba(0, 0, 0, 0.5),
    0 0 12px rgba(255, 215, 100, 0.25),
    inset 0 -2px 4px rgba(0, 0, 0, 0.35),
    inset 0 2px 3px rgba(255, 255, 255, 0.12);
}

/* 白棋：月亮（弦月） */
.cell .stone.white {
  background-color: #0f1430;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'%3E%3Cdefs%3E%3CradialGradient id='bg' cx='50%25' cy='50%25' r='68%25'%3E%3Cstop offset='0%25' stop-color='%23344a7a'/%3E%3Cstop offset='100%25' stop-color='%230a0e24'/%3E%3C/radialGradient%3E%3ClinearGradient id='m' x1='0%25' y1='0%25' x2='100%25' y2='100%25'%3E%3Cstop offset='0%25' stop-color='%23fffef2'/%3E%3Cstop offset='100%25' stop-color='%23d4cbb8'/%3E%3C/linearGradient%3E%3C/defs%3E%3Ccircle cx='50' cy='50' r='48' fill='url(%23bg)'/%3E%3Ccircle cx='38' cy='50' r='25' fill='url(%23m)'/%3E%3Ccircle cx='52' cy='47' r='21' fill='%230a0e24'/%3E%3C/svg%3E");
  background-size: cover;
  background-position: center;
  box-shadow:
    0 2px 8px rgba(0, 0, 0, 0.45),
    0 0 14px rgba(200, 220, 255, 0.15),
    inset 0 -2px 3px rgba(0, 0, 0, 0.25),
    inset 0 2px 2px rgba(255, 255, 255, 0.15);
}

.cell.last-move .stone {
  outline: 2px solid rgba(230, 57, 70, 0.85);
  outline-offset: 1px;
}

@keyframes drop {
  from {
    transform: scale(0.35);
    opacity: 0.5;
  }
  to {
    transform: scale(1);
    opacity: 1;
  }
}

/* 天元＋四星（棋盤標記，與棋子星星區隔為小光點） */
.star {
  position: absolute;
  width: 18%;
  height: 18%;
  max-width: 7px;
  max-height: 7px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.95) 0%, rgba(180, 210, 255, 0.5) 100%);
  box-shadow: 0 0 6px rgba(200, 220, 255, 0.7);
  pointer-events: none;
  z-index: 0;
}

/* --- Modal --- */
.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  z-index: 100;
}

.overlay.hidden {
  display: none;
}

.modal {
  background: var(--paper);
  border-radius: var(--radius);
  padding: 1.5rem 1.75rem;
  max-width: 360px;
  width: 100%;
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.4);
  text-align: center;
}

.modal-title {
  margin: 0 0 0.5rem;
  font-size: 1.25rem;
}

.modal-cry {
  margin: 0 auto 0.65rem;
  line-height: 0;
}

.modal-cry svg {
  display: block;
  margin: 0 auto;
  filter: drop-shadow(0 4px 10px rgba(0, 0, 0, 0.15));
  opacity: 0;
  transform: scale(0.35);
}

.modal-cry.modal-cry-animate svg {
  animation: modal-cry-pop 0.58s cubic-bezier(0.34, 1.45, 0.64, 1) forwards;
}

@keyframes modal-cry-pop {
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.modal-msg {
  margin: 0 0 1.25rem;
  color: #444;
  line-height: 1.5;
}

.modal-actions {
  display: flex;
  justify-content: center;
}

.hidden {
  display: none !important;
}

@media (max-width: 480px) {
  .toolbar {
    flex-direction: column;
    align-items: stretch;
  }

  .hint {
    flex-basis: auto;
  }

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