/* ============================================================
   楚河漢界 · 象棋衝鋒社 — 深墨胡桃木 × 朱紅 × 墨玉
   純 CSS，無框架、無外部字型、無圖片資源。
   ============================================================ */

:root {
  /* 木作色階 */
  --wood-950: #120903;
  --wood-900: #1c0f06;
  --wood-850: #241209;
  --wood-800: #33200f;
  --wood-700: #462b13;
  --wood-600: #5c3a1a;
  --wood-face-a: #7d5124;
  --wood-face-b: #5f3a17;
  --wood-frame-a: #3a2410;
  --wood-frame-b: #20120a;

  --line-color: #e3c088;
  --line-dim: #caa268;

  /* 主題色 */
  --vermilion: #c23a20;
  --vermilion-bright: #e8542f;
  --jade: #2e6b58;
  --jade-bright: #43a186;
  --jade-ink: #173f34;
  --cream: #f6e8ca;
  --cream-dim: #c9ae7f;
  --gold: #d9a441;
  --ink: #171310;

  --cell: clamp(44px, calc((100vw - 48px) / 9), 68px);
  --radius-card: 14px;

  --font-pieces: "Kaiti TC", "KaiTi", "BiauKai", "DFKai-SB", "Noto Serif TC", "Songti TC", serif;
  --font-ui: "PingFang TC", "Microsoft JhengHei", "Noto Sans TC", system-ui, sans-serif;
}

* { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

body {
  min-height: 100vh;
  color: var(--cream);
  font-family: var(--font-ui);
  line-height: 1.55;
  background:
    radial-gradient(1200px 700px at 18% -10%, rgba(232, 84, 47, 0.07), transparent 60%),
    radial-gradient(1000px 800px at 110% 110%, rgba(67, 161, 134, 0.06), transparent 55%),
    repeating-linear-gradient(93deg, rgba(255, 235, 200, 0.014) 0 3px, transparent 3px 9px),
    repeating-linear-gradient(0deg, rgba(0, 0, 0, 0.10) 0 2px, transparent 2px 7px),
    linear-gradient(160deg, var(--wood-900) 0%, var(--wood-850) 45%, var(--wood-950) 100%);
  background-attachment: fixed;
}

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  margin: -1px; padding: 0; border: 0;
  clip: rect(0 0 0 0); clip-path: inset(50%);
  overflow: hidden; white-space: nowrap;
}

.skip-link {
  position: absolute;
  left: 12px; top: -60px;
  z-index: 30;
  padding: 10px 16px;
  border-radius: 10px;
  background: var(--vermilion);
  color: #fff6ea;
  text-decoration: none;
  transition: top 0.15s ease;
}
.skip-link:focus-visible { top: 12px; }

:focus-visible {
  outline: 3px solid var(--gold);
  outline-offset: 2px;
  border-radius: 6px;
}

/* ------------------------------ 頁首 ------------------------------ */

.site-header {
  display: flex;
  align-items: center;
  gap: 14px;
  max-width: 1180px;
  margin: 0 auto;
  padding: 22px 20px 8px;
}

.brand-seal {
  display: grid;
  place-items: center;
  width: 54px; height: 54px;
  flex: none;
  border-radius: 12px;
  font-family: var(--font-pieces);
  font-size: 32px;
  font-weight: 700;
  color: #ffe9d8;
  background:
    radial-gradient(circle at 30% 25%, rgba(255, 255, 255, 0.28), transparent 45%),
    linear-gradient(150deg, var(--vermilion-bright), #96270f);
  box-shadow: inset 0 0 0 2px rgba(255, 236, 214, 0.35), 0 6px 16px rgba(0, 0, 0, 0.5);
}

.brand-text h1 {
  margin: 0;
  font-family: var(--font-pieces);
  font-size: clamp(22px, 3.4vw, 32px);
  letter-spacing: 0.06em;
  color: #fbeed3;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.55);
}

.tagline {
  margin: 2px 0 0;
  font-size: 13px;
  letter-spacing: 0.18em;
  color: rgba(246, 232, 202, 0.62);
}

/* ------------------------------ 版面 ------------------------------ */

.layout {
  max-width: 1180px;
  margin: 0 auto;
  padding: 12px 20px 40px;
  display: grid;
  grid-template-columns: minmax(0, auto) minmax(300px, 380px);
  gap: 26px;
  align-items: start;
  justify-content: center;
}

.board-zone { display: flex; flex-direction: column; align-items: center; gap: 10px; min-width: 0; }

.board-shell {
  position: relative;
  isolation: isolate;
  padding: clamp(12px, 2vw, 22px);
  border-radius: 20px;
  background:
    linear-gradient(135deg, rgba(255, 220, 160, 0.10), transparent 38%),
    repeating-linear-gradient(88deg, rgba(0, 0, 0, 0.05) 0 2px, transparent 2px 6px),
    linear-gradient(150deg, var(--wood-frame-a), var(--wood-frame-b) 70%);
  border: 1px solid rgba(227, 192, 136, 0.22);
  box-shadow:
    0 24px 60px rgba(0, 0, 0, 0.55),
    inset 0 1px 0 rgba(255, 228, 180, 0.18),
    inset 0 -3px 14px rgba(0, 0, 0, 0.45);
  overflow-x: auto;
  overscroll-behavior-x: contain;
}

#board {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  width: calc(var(--cell) * 9);
  height: calc(var(--cell) * 10);
  border-radius: 10px;
  background:
    radial-gradient(140% 90% at 30% 12%, rgba(255, 236, 190, 0.16), transparent 52%),
    repeating-linear-gradient(91deg, rgba(60, 30, 8, 0.10) 0 2px, transparent 2px 8px),
    repeating-linear-gradient(2deg, rgba(255, 230, 170, 0.045) 0 1px, transparent 1px 6px),
    linear-gradient(165deg, var(--wood-face-a), var(--wood-face-b));
  box-shadow: inset 0 0 34px rgba(31, 14, 3, 0.55);
  touch-action: manipulation;
}

.grid-lines {
  position: absolute;
  top: clamp(12px, 2vw, 22px);
  left: clamp(12px, 2vw, 22px);
  width: calc(var(--cell) * 9);
  height: calc(var(--cell) * 10);
  z-index: 1;
  pointer-events: none;
}
.grid-strokes line, .grid-strokes rect { stroke: var(--line-color); stroke-width: 1; fill: none; opacity: 0.9; vector-effect: non-scaling-stroke; }
.grid-strokes .line-bold { stroke-width: 2; opacity: 0.95; }
.grid-strokes .line-thin { stroke-width: 1.2; }
.river-text text {
  fill: var(--line-dim);
  opacity: 0.8;
  font-family: var(--font-pieces);
  font-size: 5.6px;
  letter-spacing: 1px;
}

.board-label {
  margin: 0;
  font-size: 13px;
  letter-spacing: 0.3em;
  color: rgba(246, 232, 202, 0.55);
}

.noscript-note { color: var(--vermilion-bright); font-weight: 700; }

/* ------------------------------ 格子與棋子 ------------------------------ */

.board-square {
  position: relative;
  z-index: 2;
  width: var(--cell);
  height: var(--cell);
  padding: 0;
  border: 0;
  background: transparent;
  display: grid;
  place-items: center;
  cursor: pointer;
  border-radius: 10px;
  -webkit-tap-highlight-color: transparent;
}
.board-square::after {
  /* 擴大觸控熱區至 ≥44px，即使格子因版面縮小 */
  content: "";
  position: absolute;
  inset: max(-2px, calc((var(--cell) - 44px) / -2));
}
.board-square[aria-disabled="true"] { cursor: default; }

.piece {
  position: relative;
  width: 82%;
  aspect-ratio: 1;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-family: var(--font-pieces);
  font-size: calc(var(--cell) * 0.5);
  font-weight: 700;
  line-height: 1;
  user-select: none;
  background:
    radial-gradient(circle at 32% 26%, #fffaec, #f3dfae 52%, #dcbe83 100%);
  border: 1px solid #a9834b;
  box-shadow:
    0 3px 7px rgba(0, 0, 0, 0.5),
    inset 0 -4px 7px rgba(120, 80, 30, 0.35),
    inset 0 2px 4px rgba(255, 255, 255, 0.75);
  transition: transform 0.14s ease, box-shadow 0.14s ease;
}
.piece::after {
  content: "";
  position: absolute;
  inset: 7%;
  border-radius: 50%;
  border: 1.5px solid currentColor;
  opacity: 0.85;
}
.piece-red { color: var(--vermilion); text-shadow: 0 1px 0 rgba(255, 240, 210, 0.8); }
.piece-black { color: var(--jade-ink); text-shadow: 0 1px 0 rgba(235, 245, 235, 0.55); }

.is-selected { background: rgba(217, 164, 65, 0.16); }
.is-selected .piece {
  transform: translateY(-2px) scale(1.04);
  box-shadow:
    0 6px 14px rgba(0, 0, 0, 0.55),
    0 0 0 3px rgba(217, 164, 65, 0.85),
    0 0 18px rgba(217, 164, 65, 0.55);
}

.is-last-move::before {
  content: "";
  position: absolute;
  inset: 6%;
  border-radius: 10px;
  border: 2px dashed rgba(217, 164, 65, 0.55);
  pointer-events: none;
}

.is-hint::before {
  content: "";
  position: absolute;
  inset: 4%;
  border-radius: 12px;
  border: 2px dashed var(--jade-bright);
  animation: hintPulse 1.1s ease-in-out infinite alternate;
  pointer-events: none;
}

.is-legal-target::before {
  content: "";
  position: absolute;
  width: 30%;
  aspect-ratio: 1;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(66, 160, 133, 0.95) 0%, rgba(66, 160, 133, 0.35) 70%, transparent 72%);
  pointer-events: none;
}

.is-capture-target .piece { box-shadow: 0 3px 7px rgba(0, 0, 0, 0.5), 0 0 0 3px rgba(232, 84, 47, 0.9), 0 0 16px rgba(232, 84, 47, 0.5); }

@keyframes hintPulse {
  from { opacity: 0.45; transform: scale(0.97); }
  to   { opacity: 1; transform: scale(1.03); }
}

/* ------------------------------ 終局面板 ------------------------------ */

.result-panel {
  position: absolute;
  left: 50%; top: 50%;
  transform: translate(-50%, -50%);
  z-index: 12;
  width: min(86%, 340px);
  padding: 22px 20px;
  text-align: center;
  border-radius: var(--radius-card);
  border: 1px solid rgba(227, 192, 136, 0.4);
  background:
    radial-gradient(circle at 25% 15%, rgba(255, 255, 255, 0.09), transparent 42%),
    linear-gradient(155deg, rgba(38, 22, 9, 0.97), rgba(23, 12, 5, 0.97));
  box-shadow: 0 22px 60px rgba(0, 0, 0, 0.65);
}
.result-panel[hidden] { display: none; }
.result-stamp {
  margin: 0 0 6px;
  display: inline-block;
  padding: 2px 12px;
  border-radius: 999px;
  font-size: 12px;
  letter-spacing: 0.5em;
  text-indent: 0.5em;
  color: #ffd9c4;
  background: linear-gradient(150deg, var(--vermilion-bright), #8e2410);
  box-shadow: inset 0 0 0 1px rgba(255, 224, 200, 0.4);
}
.result-panel h2 { margin: 4px 0 8px; font-family: var(--font-pieces); font-size: 24px; color: #ffe9c8; }
.result-panel p { margin: 0 0 14px; font-size: 14px; color: rgba(246, 232, 202, 0.82); }
.dialog-actions { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }

/* ------------------------------ 側欄 ------------------------------ */

.panel { display: flex; flex-direction: column; gap: 16px; min-width: 0; }

.card {
  border-radius: var(--radius-card);
  border: 1px solid rgba(227, 192, 136, 0.18);
  background:
    repeating-linear-gradient(92deg, rgba(255, 230, 180, 0.02) 0 2px, transparent 2px 8px),
    linear-gradient(160deg, var(--wood-800), var(--wood-900));
  box-shadow: 0 10px 26px rgba(0, 0, 0, 0.4), inset 0 1px 0 rgba(255, 228, 180, 0.10);
  padding: 16px 16px 18px;
}

.card h2 {
  margin: 0 0 12px;
  font-size: 15px;
  letter-spacing: 0.35em;
  color: rgba(246, 232, 202, 0.78);
  border-bottom: 1px solid rgba(227, 192, 136, 0.16);
  padding-bottom: 8px;
  font-weight: 600;
}

.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.field { display: flex; flex-direction: column; gap: 4px; min-width: 0; }
.field label { font-size: 12px; letter-spacing: 0.14em; color: rgba(246, 232, 202, 0.6); }

select {
  min-height: 44px;
  padding: 8px 10px;
  border-radius: 10px;
  border: 1px solid rgba(227, 192, 136, 0.3);
  background: linear-gradient(160deg, #2c1a0c, #1d0f06);
  color: var(--cream);
  font-size: 14px;
  font-family: inherit;
}
select:disabled { opacity: 0.5; }

.turn-line {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-top: 12px;
}

.turn-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 32px;
  padding: 4px 14px;
  border-radius: 999px;
  font-weight: 700;
  letter-spacing: 0.12em;
  border: 1px solid rgba(227, 192, 136, 0.3);
  background: rgba(0, 0, 0, 0.25);
}
.turn-badge::before {
  content: "";
  width: 12px; height: 12px;
  border-radius: 50%;
  background: var(--vermilion-bright);
  box-shadow: 0 0 8px rgba(232, 84, 47, 0.8);
}
.turn-badge[data-side="black"]::before {
  background: var(--jade-bright);
  box-shadow: 0 0 8px rgba(67, 161, 134, 0.8);
}

.move-count { font-size: 12px; color: rgba(246, 232, 202, 0.55); letter-spacing: 0.1em; }

.game-status {
  margin: 10px 0 12px;
  min-height: 44px;
  display: flex;
  align-items: center;
  padding: 8px 12px;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 600;
  color: #ffe9c4;
  background: rgba(0, 0, 0, 0.28);
  border: 1px solid rgba(227, 192, 136, 0.16);
}

.actions { display: flex; flex-wrap: wrap; gap: 8px; }

.btn {
  min-height: 44px;
  min-width: 44px;
  padding: 9px 16px;
  border-radius: 11px;
  border: 1px solid rgba(227, 192, 136, 0.32);
  background: linear-gradient(165deg, #6b3f1b, #472811);
  color: var(--cream);
  font-size: 15px;
  font-family: inherit;
  letter-spacing: 0.14em;
  cursor: pointer;
  transition: filter 0.12s ease, transform 0.12s ease;
}
.btn:hover:not(:disabled) { filter: brightness(1.18); }
.btn:active:not(:disabled) { transform: translateY(1px); }
.btn:disabled { opacity: 0.42; cursor: not-allowed; }

.btn-primary {
  background:
    radial-gradient(circle at 30% 22%, rgba(255, 255, 255, 0.22), transparent 42%),
    linear-gradient(160deg, var(--vermilion-bright), #8e2410);
  border-color: rgba(255, 205, 175, 0.45);
  color: #fff3e6;
  font-weight: 700;
}

.privacy-note { margin: 10px 0 0; font-size: 12px; color: rgba(246, 232, 202, 0.5); }

.move-list {
  max-height: 220px;
  overflow-y: auto;
  border-radius: 10px;
  border: 1px solid rgba(227, 192, 136, 0.14);
  background: rgba(0, 0, 0, 0.24);
  padding: 8px 10px;
  margin-bottom: 12px;
  scrollbar-width: thin;
  scrollbar-color: var(--wood-600) transparent;
}

.move-row {
  display: grid;
  grid-template-columns: 34px 1fr 1fr;
  gap: 6px;
  padding: 3px 4px;
  border-radius: 6px;
  font-size: 14px;
}
.move-row:nth-child(odd) { background: rgba(255, 230, 180, 0.05); }
.move-number { color: rgba(246, 232, 202, 0.5); }
.move-red { color: #ffb49a; font-family: var(--font-pieces); }
.move-black { color: #9fd8c4; font-family: var(--font-pieces); }

.empty-copy { margin: 4px; font-size: 13px; color: rgba(246, 232, 202, 0.5); }

.cap-label { margin: 6px 0 4px; font-size: 12px; letter-spacing: 0.2em; color: rgba(246, 232, 202, 0.55); }
.captured { display: flex; flex-wrap: wrap; gap: 6px; min-height: 34px; }
.capture-piece {
  display: grid;
  place-items: center;
  width: 32px; height: 32px;
  border-radius: 50%;
  font-family: var(--font-pieces);
  font-size: 17px;
  font-weight: 700;
  background: radial-gradient(circle at 32% 26%, #f4e3ba, #d9bd85);
  border: 1px solid #a9834b;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.45);
}
.capture-piece.piece-red { color: var(--vermilion); }
.capture-piece.piece-black { color: var(--jade-ink); }
.capture-empty { font-size: 12px; color: rgba(246, 232, 202, 0.4); align-self: center; }

.record-list { display: flex; flex-direction: column; gap: 8px; }
.record-item {
  display: flex;
  flex-direction: column;
  padding: 8px 10px;
  border-radius: 9px;
  background: rgba(0, 0, 0, 0.22);
  border: 1px solid rgba(227, 192, 136, 0.12);
}
.record-item strong { font-size: 13px; color: #ffe3bf; }
.record-item span { font-size: 12px; color: rgba(246, 232, 202, 0.55); }

.site-footer {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 20px 30px;
  font-size: 12px;
  color: rgba(246, 232, 202, 0.42);
}

/* ------------------------------ 響應式 ------------------------------ */

@media (max-width: 1020px) {
  :root { --cell: clamp(44px, calc((min(100vw, 560px) - 58px) / 9), 56px); }
  .layout { grid-template-columns: minmax(0, 1fr); }
  .panel { max-width: 560px; width: 100%; margin: 0 auto; }
  .board-shell { max-width: 100%; }
}

@media (max-width: 480px) {
  .site-header { padding: 16px 14px 4px; }
  .layout { padding: 8px 10px 30px; gap: 16px; }
  .card { padding: 13px 12px 15px; }
  .field-row { grid-template-columns: 1fr; }
}

/* ------------------------------ 動態偏好 ------------------------------ */

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