/* ============================================================
   Backtest Panel — Three-pane layout (tree | kpi+editor | charts)
   Mirrors quote panel (price-modal-layout) architecture
   ============================================================ */

/* --- Main layout: tree left | content right --- */
#backtestPanel { height: 100%; overflow: hidden; }
#backtestPanel .panel-header { display: none; }

.bt-layout {
  display: flex;
  height: 100%;
  background: var(--color-bg-page);
}

/* --- Left: Strategy Tree --- */
.bt-tree-panel {
  width: 240px;
  min-width: 180px;
  max-width: 360px;
  border-right: 1px solid var(--color-border-default);
  display: flex;
  flex-direction: column;
  background: var(--color-bg-secondary);
  flex-shrink: 0;
}

.bt-tree-header {
  padding: 12px 14px;
  border-bottom: 1px solid var(--color-border-default);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.bt-tree-title {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--color-text-secondary);
}

.bt-tree-add {
  width: 24px;
  height: 24px;
  border-radius: 6px;
  border: 1px solid var(--color-border-default);
  background: transparent;
  color: var(--color-text-tertiary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  transition: all 0.15s;
}

.bt-tree-add:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: var(--color-accent-muted);
}

.bt-tree-list {
  flex: 1;
  overflow-y: auto;
  padding: 6px 0;
  scrollbar-width: thin;
  scrollbar-color: var(--color-border-default) transparent;
}

/* Tree group */
.bt-tree-group {
  margin-bottom: 2px;
}

.bt-tree-group-header {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--color-text-muted);
  cursor: pointer;
  user-select: none;
}

.bt-tree-group-header:hover { color: var(--color-text-tertiary); }

.bt-tree-group-chevron {
  font-size: 8px;
  transition: transform 0.2s;
}

.bt-tree-group.collapsed .bt-tree-group-chevron { transform: rotate(-90deg); }
.bt-tree-group.collapsed .bt-tree-group-items { display: none; }

/* Tree item */
.bt-tree-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 7px 14px 7px 24px;
  cursor: pointer;
  transition: background 0.1s;
  border-left: 2px solid transparent;
}

.bt-tree-item:hover {
  background: var(--color-bg-hover);
}

.bt-tree-item.active {
  background: var(--color-accent-muted);
  border-left-color: var(--color-accent);
}

.bt-tree-item-icon {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
  opacity: 0.5;
}

.bt-tree-item-name {
  font-size: 12.5px;
  color: var(--color-text-secondary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  flex: 1;
}

.bt-tree-item.active .bt-tree-item-name { color: var(--color-text-primary); font-weight: 500; }

.bt-tree-item-badge {
  font-size: 9px;
  padding: 1px 5px;
  border-radius: 3px;
  background: var(--color-accent-subtle);
  color: var(--color-accent);
  font-weight: 600;
  flex-shrink: 0;
}

/* --- Vertical splitter (tree | content) --- */
.bt-vsplitter {
  width: 5px;
  cursor: col-resize;
  background: transparent;
  position: relative;
  flex-shrink: 0;
  z-index: 2;
}

.bt-vsplitter:hover,
.bt-vsplitter.dragging {
  background: var(--color-accent-subtle);
}

.bt-vsplitter::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 3px;
  height: 30px;
  border-radius: 2px;
  background: var(--color-border-default);
  opacity: 0;
  transition: opacity 0.15s;
}

.bt-vsplitter:hover::after { opacity: 1; }

/* --- Right: Content area --- */
.bt-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  min-width: 0;
}

/* Top: KPI + editor */
.bt-content-top {
  border-bottom: 1px solid var(--color-border-default);
  overflow-y: auto;
  max-height: 45%;
  flex-shrink: 0;
}

/* Bottom: Charts + trades */
.bt-content-bottom {
  flex: 1;
  overflow-y: auto;
  padding: 12px 16px;
  scrollbar-width: thin;
  scrollbar-color: var(--color-border-default) transparent;
}

/* --- Horizontal splitter (top | bottom) --- */
.bt-hsplitter {
  height: 5px;
  cursor: row-resize;
  background: transparent;
  position: relative;
  flex-shrink: 0;
}

.bt-hsplitter:hover,
.bt-hsplitter.dragging {
  background: var(--color-accent-subtle);
}

/* --- Editor bar (inside top area) --- */
.bt-editor-bar {
  display: flex;
  gap: 8px;
  padding: 10px 16px;
  border-bottom: 1px solid var(--color-border-subtle);
  align-items: stretch;
}

.bt-editor-textarea {
  flex: 1;
  min-height: 80px;
  max-height: 160px;
  background: var(--color-bg-page);
  border: 1px solid var(--color-border-default);
  border-radius: 6px;
  padding: 10px;
  color: var(--color-text-primary);
  font-family: 'JetBrains Mono', 'Fira Code', 'SF Mono', monospace;
  font-size: 12px;
  line-height: 1.6;
  resize: vertical;
  outline: none;
  transition: border-color 0.15s;
}

.bt-editor-textarea:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 2px var(--color-accent-subtle);
}

.bt-editor-textarea::placeholder { color: var(--color-text-muted); }

.bt-editor-controls {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 100px;
}

.bt-select {
  background: var(--color-bg-page);
  border: 1px solid var(--color-border-default);
  border-radius: 5px;
  padding: 6px 8px;
  color: var(--color-text-primary);
  font-size: 12px;
  outline: none;
}

.bt-select:focus { border-color: var(--color-accent); }

.bt-run-btn {
  background: var(--color-accent);
  color: #fff;
  border: none;
  border-radius: 6px;
  padding: 8px 12px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s;
  flex: 1;
}

.bt-run-btn:hover { background: var(--color-accent-hover); }
.bt-run-btn:active { background: var(--color-accent-active); }
.bt-run-btn:disabled { opacity: 0.5; cursor: not-allowed; }

/* --- KPI Strip --- */
.bt-kpi-strip {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  gap: 1px;
  background: var(--color-border-subtle);
}

.bt-kpi {
  background: var(--color-bg-secondary);
  padding: 10px 8px;
  text-align: center;
}

.bt-kpi-label {
  font-size: 9px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.4px;
  color: var(--color-text-muted);
  margin-bottom: 3px;
}

.bt-kpi-value {
  font-size: 15px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--color-text-primary);
}

.bt-kpi-value.positive { color: #22C55E; }
.bt-kpi-value.negative { color: #EF4444; }
.bt-kpi-value.neutral { color: var(--color-text-tertiary); }

/* --- Secondary stats --- */
.bt-stats-row {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 6px 16px;
  font-size: 11px;
  color: var(--color-text-muted);
  flex-wrap: wrap;
}

.bt-stat-val { color: var(--color-text-secondary); font-weight: 500; }
.bt-divider { color: var(--color-border-strong); }

/* --- Charts grid --- */
.bt-charts-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 12px;
}

.bt-chart-card {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border-default);
  border-radius: 8px;
  padding: 12px;
  min-height: 200px;
}

.bt-chart-card.full-width { grid-column: 1 / -1; }

.bt-chart-title {
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.4px;
  color: var(--color-text-muted);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 5px;
}

.bt-chart-title::before {
  content: '';
  width: 2px;
  height: 10px;
  background: var(--color-accent);
  border-radius: 1px;
}

.bt-chart-canvas { width: 100%; height: 170px; }

/* --- Trade table --- */
.bt-trades-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 11.5px;
  font-variant-numeric: tabular-nums;
}

.bt-trades-table thead th {
  text-align: left;
  padding: 6px 8px;
  font-weight: 600;
  font-size: 9.5px;
  text-transform: uppercase;
  letter-spacing: 0.4px;
  color: var(--color-text-muted);
  border-bottom: 1px solid var(--color-border-default);
  background: var(--color-bg-secondary);
  position: sticky;
  top: 0;
  z-index: 1;
}

.bt-trades-table tbody td {
  padding: 5px 8px;
  color: var(--color-text-secondary);
  border-bottom: 1px solid var(--color-border-subtle);
}

.bt-trades-table tbody tr:hover td { background: var(--color-bg-hover); }

.bt-trade-return { font-weight: 600; }
.bt-trade-return.positive { color: #22C55E; }
.bt-trade-return.negative { color: #EF4444; }

.bt-trade-reason {
  padding: 1px 5px;
  border-radius: 3px;
  font-size: 9.5px;
  font-weight: 500;
}

.bt-trade-reason.exit_signal { background: rgba(34,197,94,0.1); color: #22C55E; }
.bt-trade-reason.stop_loss { background: rgba(239,68,68,0.1); color: #EF4444; }
.bt-trade-reason.take_profit { background: rgba(59,130,246,0.1); color: #3B82F6; }
.bt-trade-reason.trailing_stop { background: rgba(249,115,22,0.1); color: #FB923C; }

/* --- Loading / Empty --- */
.bt-loading {
  display: flex; align-items: center; justify-content: center;
  gap: 10px; padding: 60px; color: var(--color-text-tertiary); font-size: 13px;
}

.bt-loading-spinner {
  width: 18px; height: 18px;
  border: 2px solid var(--color-border-default);
  border-top-color: var(--color-accent);
  border-radius: 50%;
  animation: bt-spin 0.7s linear infinite;
}

@keyframes bt-spin { to { transform: rotate(360deg); } }

.bt-empty {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  height: 100%; color: var(--color-text-muted); gap: 8px;
}

.bt-empty-icon { font-size: 36px; opacity: 0.2; }
.bt-empty-text { font-size: 14px; color: var(--color-text-tertiary); }
.bt-empty-hint { font-size: 11px; }

/* --- Tree footer hint --- */
.bt-tree-footer {
  padding: 10px 14px;
  border-top: 1px solid var(--color-border-subtle);
  font-size: 10px;
  color: var(--color-text-muted);
  line-height: 1.5;
}

/* --- Strategy name in tree: bold on active --- */
.bt-tree-item.active {
  background: var(--color-accent-subtle);
  border-left-color: var(--color-accent);
}

.bt-tree-item.active .bt-tree-item-icon { opacity: 1; }

/* --- Second KPI row visibility fix --- */
.bt-kpi-strip + .bt-kpi-strip {
  border-top: 1px solid var(--color-border-subtle);
}

/* --- Chart card hover effect --- */
.bt-chart-card {
  transition: border-color 0.15s;
}

.bt-chart-card:hover {
  border-color: var(--color-border-strong);
}

/* --- Responsive --- */
@media (max-width: 900px) {
  .bt-tree-panel { width: 180px; }
  .bt-kpi-strip { grid-template-columns: repeat(4, 1fr); }
  .bt-charts-grid { grid-template-columns: 1fr; }
}

@media (max-width: 600px) {
  .bt-tree-panel { display: none; }
  .bt-vsplitter { display: none; }
  .bt-kpi-strip { grid-template-columns: repeat(2, 1fr); }
}