:root {
  --bg: #f5f7fb;
  --surface: #ffffff;
  --line: #dce3ef;
  --text: #1f2937;
  --muted: #64748b;
  --blue: #4a78c7;
  --board-light: #f1f1cf;
  --board-dark: #769656;
  --highlight: rgba(59, 130, 246, 0.35);
  --target: rgba(251, 146, 60, 0.35);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
}

.play-page {
  --left-pane: 53%;
  min-height: 100vh;
  display: grid;
  grid-template-columns: minmax(560px, var(--left-pane)) 8px minmax(560px, calc(100% - var(--left-pane)));
  gap: 10px;
  padding: 4px;
}

.left-stage,
.right-stage {
  background: var(--surface);
  border: 1px solid var(--line);
}

.left-stage {
  padding: 4px;
}

.left-stage,
.right-stage {
  height: calc(100vh - 8px);
  overflow: hidden;
}

.board-topbar {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 6px;
}

.btn-link {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 6px;
  background: var(--blue);
  color: #fff;
  text-decoration: none;
  font-size: 13px;
}

.board-wrap {
  background: #6b8b4a;
  border: 1px solid #6b8b4a;
  padding: 12px 10px 10px;
}

.board-shell {
  --board-size: clamp(392px, 68vh, 544px);
  width: calc(var(--board-size) + 24px);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 24px var(--board-size);
  grid-template-rows: var(--board-size) 24px;
  gap: 0;
}

.board {
  grid-column: 2;
  grid-row: 1;
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  grid-template-rows: repeat(8, 1fr);
  width: var(--board-size);
  height: var(--board-size);
  border: 2px solid rgba(92, 111, 71, 0.9);
  background: #5c6f47;
}

.square {
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  user-select: none;
  width: 100%;
  height: 100%;
}

.piece-svg {
  width: 88%;
  height: 88%;
  object-fit: contain;
  pointer-events: none;
}

.piece-text {
  font-size: 88%;
  line-height: 1;
  pointer-events: none;
  color: #111827;
}

.piece-text-min {
  font-size: 74%;
  opacity: 0.95;
}

.square.light { background: var(--board-light); }
.square.dark { background: var(--board-dark); }
.square.last-from { box-shadow: inset 0 0 0 4px rgba(255, 235, 59, 0.72); }
.square.last-to { box-shadow: inset 0 0 0 4px rgba(255, 235, 59, 0.92); }
.square.check { box-shadow: inset 0 0 0 4px rgba(244, 67, 54, 0.88); }
.square.selected { box-shadow: inset 0 0 0 4px var(--highlight); }
.square.target { box-shadow: inset 0 0 0 4px var(--target); }

.files, .ranks {
  display: grid;
  color: #111827;
  font-size: 18px;
}

.file-bottom { 
  grid-template-columns: repeat(8, 1fr); 
  grid-column: 2; 
  grid-row: 2; 
}

.rank-left { 
  grid-template-rows: repeat(8, 1fr); 
  grid-column: 1; 
  grid-row: 1; 
}

.files span,
.ranks span {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  color: rgba(16, 24, 40, 0.88);
}

.status-line {
  margin-top: 8px;
  color: #4b5563;
  font-size: 14px;
  text-align: center;
}

.control-bar {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 8px;
  margin-top: 10px;
  padding: 4px 2px;
}

.control-row {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.control-row-bottom {
  padding-left: 2px;
}

.ctrl-btn {
  width: 32px;
  height: 32px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: #fff;
  cursor: pointer;
  font-size: 14px;
}

.ctrl-btn-secondary {
  width: auto;
  min-width: 42px;
  padding: 0 10px;
}

.slider-box {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-left: 8px;
}

.slider-box label {
  font-size: 13px;
  color: #1f2937;
}

.slider-box input[type="range"] {
  width: 96px;
}

.num {
  width: 28px;
  height: 24px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: #f8fafc;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
}

.right-stage {
  grid-column: 3;
  display: grid;
  grid-template-columns: minmax(420px, 1fr) 260px;
  gap: 8px;
  padding: 6px;
  align-content: start;
}

.stage-divider {
  grid-column: 2;
  border-radius: 8px;
  background: linear-gradient(180deg, #d8e0ec 0%, #c9d3e3 100%);
  cursor: col-resize;
  position: relative;
}

.stage-divider::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 2px;
  height: 48px;
  background: rgba(79, 99, 133, 0.65);
  transform: translate(-50%, -50%);
  box-shadow: -3px 0 0 rgba(255,255,255,0.7), 3px 0 0 rgba(255,255,255,0.7);
}

.workspace-col {
  display: grid;
  grid-template-rows: minmax(340px, 1fr) auto minmax(220px, 0.95fr);
  gap: 8px;
}

.hidden {
  display: none !important;
}

.work-panel,
.bank-panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfcfe;
  padding: 6px;
  min-height: 0;
}

.tabs {
  display: flex;
  gap: 6px;
  margin-bottom: 6px;
}

.tab {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  padding: 6px 12px;
  font-size: 13px;
  cursor: pointer;
  color: #2563eb;
}

.action-tab {
  color: #94a3b8;
}

.tab.active {
  background: #eef4ff;
  border-color: #c7d6f8;
}

.panel {
  display: none;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  padding: 8px;
  height: calc(100% - 6px);
  overflow: auto;
}

.panel.active { display: block; }

.panel h3 {
  margin: 8px 0;
  font-size: 14px;
}

.placeholder {
  color: #475569;
  font-size: 13px;
  margin-bottom: 8px;
}

.notation-list {
  margin: 0;
  padding-left: 22px;
}

.log-console {
  height: calc(100% - 34px);
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #0f172a;
  color: #cbd5e1;
  font-family: Consolas, "Courier New", monospace;
  font-size: 12px;
  overflow: auto;
  padding: 8px;
}

.inline-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
}

.soft-btn {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f8fafc;
  color: #16a34a;
  padding: 7px 10px;
  cursor: pointer;
}

.expand-panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  padding: 10px;
  overflow: auto;
}

.expand-placeholder {
  color: #475569;
  font-size: 14px;
}

.log-line { margin-bottom: 4px; }
.log-line.error { color: #fda4af; }
.log-line.warn { color: #fcd34d; }
.log-line.info { color: #93c5fd; }

.bank-panel h3 {
  margin: 4px 0 8px;
  font-size: 14px;
}

.bank-tree {
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 13px;
  color: #334155;
}

.bank-tree li {
  padding: 6px 4px;
  border-bottom: 1px dashed #e5e7eb;
}

.ai-vs-ai-panel {
  grid-column: 1 / -1;
  display: grid;
  grid-template-rows: 1fr 1fr;
  gap: 12px;
  height: 100%;
  min-height: 0;
}

.human-ai-panel {
  grid-column: 1 / -1;
  display: grid;
  grid-template-rows: 1fr;
  gap: 12px;
  height: 100%;
  min-height: 0;
}

.engine-card {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fbfcfe;
  padding: 6px;
  display: grid;
  grid-template-rows: auto 1fr;
  gap: 6px;
  min-height: 0;
}

.engine-title {
  border-radius: 6px;
  color: #fff;
  text-align: center;
  font-size: 14px;
  font-weight: 700;
  padding: 5px 10px;
}

.engine-card-black .engine-title {
  background: #33475b;
}

.engine-card-white .engine-title {
  background: #ef4d37;
}

.engine-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 6px;
  min-height: 0;
}

.engine-body-single {
  padding-top: 2px;
}

.single-engine-card {
  padding-top: 8px;
}

.engine-main,
.engine-side {
  display: grid;
  gap: 6px;
}

.engine-main {
  grid-template-rows: auto auto 1fr;
}

.engine-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
}

.ai-group {
  border: 1px solid #dbe8fb;
  border-radius: 8px;
  background: #fff;
  padding: 6px;
}

.ai-group-title {
  color: #54657a;
  font-size: 12px;
  font-weight: 700;
  margin-bottom: 6px;
}

.advantage-bar {
  display: grid;
  grid-template-columns: 1fr 1fr;
  height: 18px;
  border: 1px solid #d7e2f3;
  border-radius: 6px;
  overflow: hidden;
  margin-bottom: 6px;
}

.advantage-white {
  background: #28b446;
}

.advantage-black {
  background: #ea394b;
}

.advantage-text,
.setting-placeholder,
.pv-box,
.eval-box,
.metric-item,
.setting-row {
  border: 1px solid #dbe8fb;
  border-radius: 6px;
  background: #fdfefe;
  color: #475569;
  font-size: 11px;
  padding: 5px 8px;
}

.pv-box,
.eval-box {
  min-height: 46px;
  display: flex;
  align-items: center;
}

.eval-box {
  min-height: 64px;
  background: #edf5ff;
}

.eval-box-rich {
  display: grid;
  align-content: start;
  gap: 8px;
  min-height: 78px;
}

.metric-list {
  display: grid;
  gap: 4px;
}

.setting-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.setting-value {
  color: #1e3a8a;
  font-weight: 700;
}

.engine-select {
  min-width: 120px;
  border: 1px solid #c9d8f1;
  border-radius: 5px;
  padding: 2px 6px;
  background: #fff;
  color: #334155;
  font-size: 11px;
}

@media (max-width: 1360px) {
  .play-page {
    --left-pane: 100%;
    grid-template-columns: 1fr;
  }

  .stage-divider {
    display: none;
  }

  .right-stage {
    grid-column: 1;
    grid-template-columns: 1fr;
  }

  .engine-body,
  .engine-grid {
    grid-template-columns: 1fr;
  }

  .workspace-col {
    grid-template-rows: 320px auto 220px;
  }

  .work-panel,
  .bank-panel {
    min-height: auto;
  }

  .panel {
    height: 300px;
  }

  .board-shell {
    --board-size: min(74vw, 520px);
  }
}