:root {
  --bg: #f6f5f2;
  --surface: #ffffff;
  --ink: #1d1c1a;
  --ink-dim: #6b6862;
  --line: #dcd9d1;
  --off: #e6e3db;
  --on: #e8a33d;
  --good: #2f7a54;
  --warn: #a06a12;
  --bad: #a8332e;
  --radius: 10px;
  color-scheme: light;
}

* { box-sizing: border-box; }

html, body { height: 100%; }

body {
  margin: 0;
  overflow: hidden;
  background: var(--bg);
  color: var(--ink);
  font: 15px/1.6 ui-sans-serif, system-ui, -apple-system, "Segoe UI", "PingFang SC",
        "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
  /* 触屏：去掉点击的蓝色高亮、长按弹菜单、误触选中文字 */
  -webkit-tap-highlight-color: transparent;
  -webkit-touch-callout: none;
}

canvas {
  -webkit-tap-highlight-color: transparent;
  -webkit-touch-callout: none;
  user-select: none;
  -webkit-user-select: none;
}

/* 两栏：左栏放全部设置，右栏只放棋盘。 */
.app {
  display: grid;
  grid-template-columns: 360px minmax(0, 1fr);
  height: 100dvh;
}

.rail {
  display: flex;
  flex-direction: column;
  gap: 20px;
  padding: 24px 22px 20px;
  overflow-y: auto;
  background: var(--surface);
  border-right: 1px solid var(--line);
}

.masthead h1 {
  margin: 0;
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.controls {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.group {
  display: flex;
  flex-direction: column;
  gap: 7px;
}

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

.row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.row.grid2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
}

.times {
  color: var(--ink-dim);
  font-size: 13px;
}

input[type="number"] {
  width: 72px;
  padding: 8px 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
  font: inherit;
  font-variant-numeric: tabular-nums;
}

input[type="number"]:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 1px;
}

button {
  padding: 9px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
  font: inherit;
  font-size: 14px;
  cursor: pointer;
  transition: background 120ms ease, border-color 120ms ease, transform 80ms ease,
    box-shadow 120ms ease;
}

button:hover:not(:disabled) {
  border-color: #c3bfb4;
}

button:active:not(:disabled) {
  transform: translateY(1px);
}

button:disabled {
  opacity: 0.45;
  cursor: default;
}

button.primary {
  flex: 1;
  background: var(--ink);
  border-color: var(--ink);
  color: #fdfcfa;
}

button.primary:hover:not(:disabled) {
  background: #33312d;
}

button:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 2px;
}

/* 分段控件按内容宽度靠左，不能被 flex/grid 拉宽 */
.seg {
  display: inline-flex;
  align-self: flex-start;
  gap: 2px;
  padding: 2px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.seg button {
  border: none;
  background: transparent;
  padding: 7px 14px;
  border-radius: 8px;
}

.seg button[aria-pressed="true"] {
  background: var(--ink);
  color: #fdfcfa;
}

.seg button[aria-pressed="true"]:disabled {
  opacity: 0.6;
}

/* 结果卡贴在左栏底部；高度固定，不随求解状态/内容多少而改变 */
.result {
  margin-top: auto;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--bg);
  font-size: 13px;
  height: 300px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
}

.result strong {
  display: block;
  margin-bottom: 6px;
  font-size: 14px;
  font-weight: 600;
}

.result.good strong { color: var(--good); }
.result.warn strong { color: var(--warn); }
.result.bad strong { color: var(--bad); }

.result.pending { color: var(--ink-dim); }

.result-head {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin-bottom: 10px;
  color: var(--ink-dim);
}

.result-count {
  color: var(--ink);
  font-size: 26px;
  font-weight: 600;
  line-height: 1;
  font-variant-numeric: tabular-nums;
}

.result-note {
  margin: 8px 0 0;
  font-size: 12px;
  line-height: 1.5;
  color: var(--ink-dim);
}

.result-note.warn { color: var(--warn); }
.result-note.bad { color: var(--bad); }

.result-detail {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 3px 12px;
  margin: 10px 0 0;
  padding-top: 10px;
  border-top: 1px solid var(--line);
  font-size: 12px;
}

.result-detail dt { color: var(--ink-dim); }

.result-detail dd {
  margin: 0;
  text-align: right;
  font-variant-numeric: tabular-nums;
}

/* 结果卡下方的源代码仓库入口 */
.source-link {
  align-self: center;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  margin-top: -14px;
  border-radius: 8px;
  color: var(--ink-dim);
  transition: color 120ms ease, background 120ms ease;
}

.source-link:hover {
  color: var(--ink);
  background: var(--bg);
}

.source-link:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 2px;
}

/* 右栏：左键只负责下棋，右键 / 中键 / 空格负责移动视图。 */
.stage {
  position: relative;
  min-width: 0;
  overflow: hidden;
  outline: none;
  /* 触屏：整个棋盘区声明「不接受浏览器默认滚动/缩放手势」，
     否则手指滑动会被浏览器判定为滚动，触发 pointercancel 打断我们的手势 */
  touch-action: none;
}

.stage:focus-visible {
  box-shadow: inset 0 0 0 2px rgba(29, 28, 26, 0.24);
}

.board-canvas {
  position: absolute;
  inset: 0;
  z-index: 0;
  display: block;
  width: 100%;
  height: 100%;
}

canvas.board-canvas {
  cursor: default;
  touch-action: none;
}

.board-overlay {
  pointer-events: none;
}

.stage.over-cell canvas.board-canvas {
  cursor: pointer;
}

.stage.pan-ready canvas.board-canvas {
  cursor: grab;
}

.stage.dragging canvas.board-canvas {
  cursor: grabbing;
}

.play-status {
  position: absolute;
  top: 18px;
  left: 18px;
  z-index: 3;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 34px;
  padding: 6px 12px;
  border: 1px solid rgba(220, 217, 209, 0.9);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.9);
  box-shadow: 0 2px 10px rgba(29, 28, 26, 0.06);
  backdrop-filter: blur(8px);
  color: var(--ink-dim);
  font-size: 12px;
  white-space: nowrap;
  pointer-events: none;
  transition: color 160ms ease, border-color 160ms ease;
}

.status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #8b8881;
  transition: background 160ms ease, box-shadow 160ms ease;
}

.stage[data-phase="guiding"] .play-status {
  color: var(--ink);
  border-color: rgba(232, 163, 61, 0.6);
}

.stage[data-phase="guiding"] .status-dot {
  background: var(--on);
  box-shadow: 0 0 0 4px rgba(232, 163, 61, 0.14);
}

.stage[data-phase="solving"] .status-dot {
  background: var(--on);
  animation: status-pulse 900ms ease-in-out infinite alternate;
}

.stage[data-phase="done"] .play-status {
  color: var(--good);
  border-color: rgba(47, 122, 84, 0.35);
}

.stage[data-phase="done"] .status-dot {
  background: var(--good);
}

@keyframes status-pulse {
  to { opacity: 0.35; }
}

.view-controls {
  position: absolute;
  right: 18px;
  bottom: 18px;
  z-index: 3;
  display: flex;
  align-items: center;
  gap: 3px;
  padding: 4px;
  border: 1px solid rgba(220, 217, 209, 0.92);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.92);
  box-shadow: 0 2px 12px rgba(29, 28, 26, 0.09);
  backdrop-filter: blur(8px);
}

.view-controls button {
  min-width: 32px;
  height: 32px;
  padding: 0 8px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--ink-dim);
  font-size: 17px;
  line-height: 1;
}

.view-controls button:hover:not(:disabled) {
  background: var(--bg);
  color: var(--ink);
}

.view-controls .view-reset {
  margin-left: 3px;
  border-left: 1px solid var(--line);
  border-radius: 0 8px 8px 0;
  padding-inline: 12px;
  font-size: 12px;
}

.zoom-level {
  min-width: 44px;
  color: var(--ink-dim);
  text-align: center;
  font-size: 11px;
  font-variant-numeric: tabular-nums;
  user-select: none;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

@media (max-width: 900px) {
  body { overflow: hidden; }

  .app {
    grid-template-columns: minmax(0, 1fr);
    grid-template-rows: auto minmax(0, 1fr);
    height: 100dvh;
    overflow: hidden;
  }

  .rail {
    border-right: none;
    border-bottom: 1px solid var(--line);
    overflow-y: auto;
    max-height: 44vh;
    flex-shrink: 0;
  }

  .stage {
    min-height: 0;
    flex: 1;
  }

  .result {
    height: 180px;
    flex-shrink: 0;
  }
}