:root {
  --bg: #1c2521;          /* 黒板の緑がかった墨色 */
  --surface: #25302b;
  --line: rgba(236, 240, 230, 0.13);
  --thick: rgba(236, 240, 230, 0.85);  /* 小盤どうしの太い線 */
  --thin: #3a4540;                     /* 小盤の中の細い線。透けると下の太い線の色が出るので不透明に */
  --fg: #eef1ea;
  --muted: #9ea8a1;
  --o: #f1cd6a;           /* ○: 黄色いチョーク */
  --x: #eef1ea;           /* ×: 白いチョーク */

  --wak-bg: #25302b;
  --wak-fg: #eef1ea;
  --wak-muted: #9ea8a1;
  --wak-line: rgba(236, 240, 230, 0.14);
  --wak-accent: #f1cd6a;
  --wak-accent-fg: #2a2410;
}

* { box-sizing: border-box; }

/* Safari 26 の上下バーの色は html の背景から取られる。body と同じ色にしておく */
html { background-color: var(--bg); -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background-color: var(--bg);
  color: var(--fg);
  font-family: system-ui, -apple-system, 'Hiragino Sans', 'Noto Sans JP', sans-serif;
  -webkit-tap-highlight-color: transparent;
}
button { font: inherit; color: inherit; }
[hidden] { display: none !important; }

.app {
  height: 100dvh;
  display: flex;
  flex-direction: column;
  padding:
    max(12px, env(safe-area-inset-top))
    max(12px, env(safe-area-inset-right))
    max(12px, env(safe-area-inset-bottom))
    max(12px, env(safe-area-inset-left));
  touch-action: manipulation;   /* ダブルタップ拡大を止める */
  user-select: none;
  -webkit-user-select: none;
}

.btn {
  min-height: 48px;
  padding: 0 18px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface);
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
}
.btn--main { border-color: transparent; background: var(--o); color: #2a2410; }
.btn--quiet { background: transparent; }
.btn:disabled { opacity: 0.4; cursor: default; }
.btn small { display: block; font-size: 11px; font-weight: 400; color: var(--muted); }
.btn--main small { color: #6b5c26; }
.pill {
  min-height: 44px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.05);
  border-radius: 999px;
  padding: 6px 14px;
  font-size: 13px;
  cursor: pointer;
}
.pill[aria-pressed="false"] { color: var(--muted); }
.link-btn { display: block; margin: 8px auto 0; border: 0; background: none; color: var(--muted); font-size: 13px; text-decoration: underline; cursor: pointer; }
.credit { text-align: center; font-size: 12px; color: var(--muted); }
.credit a { color: inherit; }

/* ---- タイトル ---- */
.title { flex: 1; min-height: 0; overflow-y: auto; display: flex; flex-direction: column; }
.title__main { flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 10px; text-align: center; }
.board--demo { width: 128px; margin-bottom: 6px; pointer-events: none; }
.title__name { margin: 0; font-size: 30px; letter-spacing: 0.02em; font-weight: 800; }
.title__lead { margin: 0 0 12px; color: var(--muted); font-size: 14px; }
.title__buttons { display: grid; gap: 10px; width: min(280px, 100%); }
.title__stats { min-height: 1.5em; margin: 14px 0 0; font-size: 13px; color: var(--muted); }
.title__foot { display: grid; gap: 12px; padding-top: 16px; }
.title__kit { display: flex; justify-content: center; flex-wrap: wrap; gap: 8px; }

@media (max-height: 620px) {
  .board--demo { display: none; }
}

/* ---- 強さと先手・後手（AI と対戦） ---- */
.setup { flex: 1; min-height: 0; overflow-y: auto; display: flex; flex-direction: column; gap: 14px; padding-top: 4px; }
.setup__head { display: flex; align-items: center; gap: 8px; }
.setup__head h2 { flex: 1; margin: 0; text-align: center; font-size: 18px; }
.setup__spacer { width: 44px; }
.setup__note { margin: 0; text-align: center; font-size: 12px; color: var(--muted); }
.levels { display: grid; gap: 8px; }
.level-btn { display: flex; align-items: center; justify-content: space-between; gap: 8px; text-align: left; width: 100%; }
.level-btn small { color: var(--muted); font-size: 12px; }
.level-btn.selected { border-color: var(--o); background: color-mix(in srgb, var(--surface) 80%, var(--o) 14%); }
.sides { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; }
.side-btn { padding: 0 8px; font-size: 14px; }
.side-btn.selected { border-color: var(--o); background: color-mix(in srgb, var(--surface) 80%, var(--o) 14%); }

/* ---- 盤（対局・タイトルの見本で共通） ---- */
.board {
  position: relative;
  aspect-ratio: 1;
  display: grid;
  grid-template: repeat(3, 1fr) / repeat(3, 1fr);
  gap: 5px;
  background: var(--thick);
  border-radius: 10px;
  overflow: hidden;
}
.sub {
  position: relative;
  display: grid;
  grid-template: repeat(3, 1fr) / repeat(3, 1fr);
  gap: 1px;
  background: var(--thin);
}
.cell {
  position: relative;
  margin: 0; padding: 0; border: 0;
  background: #141a17;        /* 打てない小盤は暗いまま */
  transition: background 0.15s;
  display: flex; align-items: center; justify-content: center;
}
/* 打てる小盤は黄色みを帯びた明るさと黄色い枠で示す。フリーターンなら決着していない小盤が全部これになる */
.sub.playable .cell { background: color-mix(in srgb, var(--surface) 78%, var(--o) 22%); }
.sub.playable::after { content: ''; position: absolute; inset: 0; z-index: 1; box-shadow: inset 0 0 0 3px var(--o); pointer-events: none; }
.sub.playable.flash .cell { animation: sub-flash 0.5s ease-out; }
@keyframes sub-flash { from { background: var(--o); } }
#board .cell { cursor: pointer; touch-action: manipulation; }
#board .cell:disabled { cursor: default; }
@media (hover: hover) {
  #board .sub.playable .cell:not(:disabled):hover { background: color-mix(in srgb, var(--surface) 62%, var(--o) 38%); }
}
.cell.shake { animation: shake 0.28s; }
@keyframes shake { 25% { transform: translateX(-3px); } 50% { transform: translateX(3px); } 75% { transform: translateX(-1.5px); } }

.mark { width: 62%; height: 62%; }
.mark.o { color: var(--o); }
.mark.x { color: var(--x); }
.glyph { fill: none; stroke: currentColor; stroke-width: 10; stroke-linecap: round; }
.mark.pending { opacity: 0.4; }
.cell.last .mark { filter: drop-shadow(0 0 3px currentColor); }

/* 決着した小盤: 大きな ×/○ を上から重ねる。中の印は薄く残す */
.sub-owner {
  position: absolute; inset: 0; z-index: 2;
  display: flex; align-items: center; justify-content: center;
  background: rgba(28, 37, 33, 0.72);
  pointer-events: none;
}
.sub-owner svg { width: 68%; height: 68%; }
.sub.owner-x .sub-owner svg { color: var(--x); }
.sub.owner-o .sub-owner svg { color: var(--o); }
.sub.drawn .sub-owner { background: rgba(120, 120, 120, 0.55); }
.sub:not(.taken):not(.drawn) .sub-owner { display: none; }
.sub.taken .cell .mark, .sub.drawn .cell .mark { opacity: 0.55; }

.board__win { position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none; z-index: 3; overflow: visible; display: none; }
.board[data-win] .board__win { display: block; }
.board__win line { stroke-width: 1.6; stroke-linecap: round; stroke-dasharray: 140; opacity: 0.95; animation: draw-line 0.35s ease-out both; }
.board[data-win="o"] .board__win line { stroke: var(--o); filter: drop-shadow(0 0 2px var(--o)); }
.board[data-win="x"] .board__win line { stroke: var(--x); filter: drop-shadow(0 0 2px var(--x)); }
@keyframes draw-line { from { stroke-dashoffset: 140; } to { stroke-dashoffset: 0; } }

@media (prefers-reduced-motion: reduce) {
  .sub, .cell.shake, .board__win line, .sub.playable.flash { animation: none; transition: none; }
}

/* ---- 対局 ---- */
.game { position: relative; flex: 1; min-height: 0; display: flex; flex-direction: column; gap: 8px; }
.top { display: grid; grid-template-columns: 44px 1fr 44px; align-items: center; gap: 8px; }
.icon-btn {
  width: 44px; height: 44px;
  border: 1px solid var(--line); border-radius: 12px; background: var(--surface);
  font-size: 20px; line-height: 1; cursor: pointer;
}
.turn { margin: 0; text-align: center; font-size: 16px; font-weight: 700; }
.ply { margin: 0; text-align: right; font-size: 13px; color: var(--muted); font-variant-numeric: tabular-nums; white-space: nowrap; }
.free-turn { margin: 0; text-align: center; font-size: 12px; color: var(--o); min-height: 1.2em; }

/* AI 対戦の帯: 手番の側を明るく、考えている間は小さく点滅 */
.ai-bar { display: flex; justify-content: space-between; padding: 0 4px; font-size: 13px; color: var(--muted); }
.ai-bar .side { display: flex; align-items: baseline; gap: 4px; }
.ai-bar .side.active { color: var(--fg); font-weight: 700; }
.ai-bar .side.thinking { animation: ai-blink 1s steps(2, jump-none) infinite; }
@keyframes ai-blink { 50% { opacity: 0.35; } }
@media (prefers-reduced-motion: reduce) {
  .ai-bar .side.thinking { animation: none; opacity: 0.7; }
}

.debug {
  position: fixed; right: 6px; bottom: max(6px, env(safe-area-inset-bottom));
  padding: 3px 8px; border-radius: 8px;
  background: rgba(0, 0, 0, 0.5); color: #fff;
  font-size: 11px; font-variant-numeric: tabular-nums;
  pointer-events: none; z-index: 20;
}

.board-wrap { flex: 1; min-height: 0; container-type: size; display: flex; align-items: center; justify-content: center; }
#board { width: min(100cqw, 100cqh, 440px); }

/* 結果: 盤の上に、下寄せのカードで重ねる（盤は見えたまま） */
.game__buttons { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.result {
  position: absolute; left: 0; right: 0; bottom: 0; z-index: 4;
  width: min(420px, 100%); margin: 0 auto;
  padding: 16px; border-radius: 18px; border: 1px solid var(--line);
  background: color-mix(in srgb, var(--surface) 94%, transparent);
  box-shadow: 0 -8px 30px rgba(0, 0, 0, 0.35);
  text-align: center;
}
.result p { margin: 0 0 4px; }
.result__head { font-size: 24px; font-weight: 800; }
.result__head.o { color: var(--o); }
.result__sub { font-size: 13px; color: var(--muted); }
.result__buttons { display: grid; grid-template-columns: repeat(2, 1fr); gap: 8px; margin-top: 12px; }
.result__buttons #again { grid-column: 1 / -1; }
.result__buttons .btn { padding: 0 6px; white-space: nowrap; font-size: 14px; }

/* ---- メニュー・遊び方（dialog 共通） ---- */
.menu, .help {
  width: min(420px, calc(100% - 24px)); max-height: calc(100dvh - 48px);
  padding: 20px; border: 1px solid var(--line); border-radius: 18px;
  background: var(--surface); color: var(--fg); line-height: 1.65; font-size: 15px;
}
.menu::backdrop, .help::backdrop { background: rgba(0, 0, 0, 0.6); }
.menu h2, .help h2 { margin: 0 0 8px; font-size: 20px; }
.menu h3 { margin: 16px 0 8px; font-size: 14px; color: var(--muted); }
.menu__list { display: grid; gap: 8px; }
.menu .row { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin: 10px 0; font-size: 14px; }
.menu .btn { width: 100%; margin-top: 8px; }
.help ol { margin: 0; padding-left: 1.3em; }
.help li + li { margin-top: 4px; }
.help__note { margin: 12px 0 0; font-size: 13px; color: var(--muted); }
.help .btn { width: 100%; margin-top: 16px; }