/* Interactive labs + ERD. Labs sit on graph paper: the course's printout motif. */

.lab {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--s-3);
  padding: 16px;
  border: 1px solid var(--rule);
  border-radius: var(--r-md);
  background-color: var(--surface);
  background-image:
    linear-gradient(var(--paper-grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--paper-grid) 1px, transparent 1px);
  background-size: 22px 22px;
}

.lab.lab-flush {
  padding: 0;
  overflow: hidden;
}

.lab-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--s-3);
}

.lab-choices {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.lab-choice {
  padding: 5px 12px;
  border: 1px solid var(--rule-strong);
  border-radius: var(--r-pill);
  background: var(--surface);
  color: var(--ink-2);
  font-size: var(--fs-xs);
  font-weight: 600;
  cursor: pointer;
  transition: background var(--dur-fast), color var(--dur-fast), border-color var(--dur-fast);
}

.lab-choice:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.lab-choice[aria-pressed="true"] {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-ink);
}

.lab-custom {
  display: flex;
  gap: var(--s-2);
  flex: 1 1 280px;
}

.lab-custom input {
  flex: 1;
  min-width: 0;
  font-family: var(--font-mono);
}

.lab-sql {
  font-size: 0.84rem;
  padding: 8px 12px;
}

.lab-summary {
  font-size: var(--fs-sm);
  color: var(--ink-2);
}

.lab-summary strong {
  color: var(--ink);
  font-family: var(--font-mono);
}

.lab-summary-note {
  color: var(--warn);
}

.lab-caption {
  font-size: var(--fs-xs);
  font-weight: 700;
  color: var(--ink-3);
  letter-spacing: 0.02em;
  margin-block-end: 4px;
}

.lab-error {
  padding: 8px 12px;
  border-radius: var(--r-sm);
  background: var(--bad-soft);
  color: var(--bad);
  font-size: var(--fs-sm);
}

.lab-info {
  display: grid;
  gap: 4px;
  padding: 10px 14px;
  border-radius: var(--r-sm);
  background: var(--surface);
  border: 1px solid var(--rule);
  font-size: var(--fs-sm);
}

.lab-info-item strong {
  color: var(--ink);
}

.lab-info-item.is-row strong {
  box-shadow: inset 0 -0.45em 0 var(--highlight-wash);
}

.lab-info-item.is-col strong {
  box-shadow: inset 0 -0.45em 0 color-mix(in srgb, var(--accent) 22%, transparent);
}

.lab-table-wrap {
  overflow-x: auto;
  border: 1px solid var(--rule);
  border-radius: var(--r-sm);
  background: var(--surface);
}

.lab-table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  text-align: left;
  direction: ltr;
}

.lab-table caption {
  caption-side: top;
  text-align: left;
  padding: 6px 10px;
  font-family: var(--font-body);
  font-size: var(--fs-xs);
  color: var(--ink-3);
}

.lab-table th,
.lab-table td {
  padding: 6px 12px;
  border-bottom: 1px solid var(--rule);
  white-space: nowrap;
}

.lab-table thead th {
  background: var(--surface-2);
  color: var(--ink-2);
  font-weight: 600;
  font-size: 0.78rem;
}

.lab-table td.is-num {
  text-align: right;
  font-variant-numeric: tabular-nums;
}

.lab-table tbody tr {
  transition: background var(--dur), opacity var(--dur);
}

/* ---------------------------------------------------------------- anatomy */
.anatomy-table td {
  cursor: pointer;
}

.anatomy-table tr.is-row-on td {
  background: var(--highlight-wash);
}

.anatomy-table .is-col-on {
  background: color-mix(in srgb, var(--accent) 14%, var(--surface));
}

.anatomy-table tr.is-row-on td.is-col-on {
  background: color-mix(in srgb, var(--highlight) 45%, color-mix(in srgb, var(--accent) 20%, var(--surface)));
}

.anatomy-table td.is-cell-on {
  outline: 2px solid var(--accent);
  outline-offset: -2px;
  font-weight: 600;
}

.anatomy-table th .key-badge {
  margin-inline-start: 6px;
}

/* ---------------------------------------------------------------- filter */
.filter-table .verdict-col {
  font-family: var(--font-body);
}

.filter-table .verdict {
  font-family: var(--font-body);
  font-size: var(--fs-xs);
  color: var(--ink-3);
}

.filter-table .verdict svg {
  width: 14px;
  height: 14px;
  vertical-align: -2px;
  margin-inline-end: 4px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2.4;
}

.filter-table tr.is-kept td {
  background: var(--highlight-wash);
}

.filter-table tr.is-kept td:first-child {
  box-shadow: inset 4px 0 0 var(--highlight);
}

.filter-table tr.is-kept .verdict {
  color: var(--ok);
  font-weight: 600;
}

.filter-table tr.is-dropped td:not(.verdict) {
  opacity: 0.42;
  text-decoration: line-through;
  text-decoration-color: var(--ink-3);
}

.filter-table tr.is-dropped .verdict {
  color: var(--bad);
}

.filter-table tr.is-unknown td:not(.verdict) {
  opacity: 0.5;
}

.filter-table tr.is-unknown .verdict {
  color: var(--warn);
}

.filter-table .verdict .null-cell {
  margin-inline-end: 6px;
}

/* ---------------------------------------------------------------- null logic */
.logic-controls {
  gap: var(--s-5);
}

.logic-picker {
  display: flex;
  align-items: center;
  gap: var(--s-2);
}

.logic-picker-label {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--fs-md);
}

.logic-results,
.logic-comparisons {
  display: grid;
  gap: 6px;
}

.logic-row {
  display: flex;
  align-items: center;
  gap: var(--s-2);
  direction: ltr;
  justify-content: flex-end;
}

.logic-eq {
  color: var(--ink-3);
  font-family: var(--font-mono);
}

.logic-chip {
  display: inline-block;
  min-width: 58px;
  padding: 1px 10px;
  border-radius: var(--r-pill);
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  font-weight: 700;
  text-align: center;
  background: var(--surface-2);
  color: var(--ink-2);
}

.logic-chip.is-true {
  background: var(--ok-soft);
  color: var(--ok);
}

.logic-chip.is-false {
  background: var(--bad-soft);
  color: var(--bad);
}

.logic-chip.is-null {
  background: var(--surface-3);
  color: var(--ink-3);
  font-style: italic;
}

.logic-tables {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--s-3);
}

.logic-table th,
.logic-table td {
  text-align: center;
}

.logic-table td.is-active {
  background: var(--highlight-wash);
  outline: 2px solid var(--highlight);
  outline-offset: -2px;
}

/* ---------------------------------------------------------------- group */
.group-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: var(--s-3);
  align-items: start;
}

.group-layout > *,
.join-side {
  min-width: 0;
}

.index-output,
.index-step,
.logic-results,
.logic-comparisons,
.lab-info {
  grid-template-columns: minmax(0, 1fr);
}

.group-result:empty {
  display: none;
}

.group-layout:has(.group-result:empty) {
  grid-template-columns: minmax(0, 1fr);
}

.group-stage {
  font-family: var(--font-body);
  padding-inline: 12px;
}

[data-group="0"] { --g: var(--series-1); }
[data-group="1"] { --g: var(--series-2); }
[data-group="2"] { --g: var(--series-3); }
[data-group="3"] { --g: var(--series-4); }

.group-table tr[data-group]:not([data-group=""]) td,
.group-summary tr[data-group] td,
.window-table tr[data-group]:not([data-group=""]) td {
  background: color-mix(in srgb, var(--g) 11%, var(--surface));
}

.group-table tr[data-group]:not([data-group=""]) td:first-child,
.group-summary tr[data-group] td:first-child,
.window-table tr[data-group]:not([data-group=""]) td:first-child {
  box-shadow: inset 4px 0 0 var(--g);
}

.group-summary td:last-child {
  font-family: var(--font-mono);
  color: var(--ink-3);
  white-space: normal;
  min-width: 160px;
}

/* ---------------------------------------------------------------- join */
.join-header {
  display: flex;
  align-items: center;
  gap: var(--s-4);
}

.join-venn .venn {
  width: 110px;
  height: 64px;
}

.venn-fill {
  fill: var(--accent);
  opacity: 0.32;
}

.venn-ring {
  fill: none;
  stroke: var(--ink-2);
  stroke-width: 1.4;
}

.join-text {
  font-size: var(--fs-sm);
  color: var(--ink-2);
}

.join-stage {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 70px minmax(0, 1fr);
  align-items: start;
}

.join-side:first-child {
  grid-column: 1;
}

.join-side.join-right {
  grid-column: 3;
}

.join-lines {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  overflow: visible;
}

.join-line {
  fill: none;
  stroke: var(--accent);
  stroke-width: 1.6;
  opacity: 0.8;
}

.join-line.is-faint {
  opacity: 0.22;
  stroke-width: 1;
}

.join-side tr.is-matched td {
  background: var(--highlight-wash);
}

.join-side tr.is-kept-null td {
  background: color-mix(in srgb, var(--warn) 12%, var(--surface));
}

.join-side tr.is-out td {
  opacity: 0.38;
  text-decoration: line-through;
}

/* ---------------------------------------------------------------- window */
.window-table tbody tr {
  cursor: pointer;
}

.window-table tr.is-frame td {
  background: var(--highlight-wash) !important;
}

.window-table tr.is-current td {
  outline: 2px solid var(--accent);
  outline-offset: -2px;
  font-weight: 600;
}

.window-table .result-cell {
  color: var(--accent);
  font-weight: 600;
}

/* ---------------------------------------------------------------- index lab */
.index-output {
  display: grid;
  gap: var(--s-3);
}

.index-step {
  display: grid;
  gap: 6px;
}

.index-plan {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--s-2);
  padding: 8px 12px;
  border-radius: var(--r-sm);
  background: var(--surface-2);
  font-size: 0.82rem;
}

.index-plan-label {
  font-size: var(--fs-2xs);
  font-weight: 700;
  color: var(--ink-3);
  letter-spacing: 0.04em;
}

.index-time {
  font-size: var(--fs-sm);
  font-weight: 600;
}

.index-chart {
  border: 1px solid var(--rule);
  border-radius: var(--r-sm);
}

/* ---------------------------------------------------------------- ERD */
.erd-wrap {
  overflow-x: auto;
  direction: ltr;
  background-color: var(--surface);
  background-image:
    linear-gradient(var(--paper-grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--paper-grid) 1px, transparent 1px);
  background-size: 22px 22px;
}

.erd-svg {
  display: block;
  min-width: 100%;
}

.erd-svg text {
  font-family: var(--font-mono);
  font-size: 11.5px;
  fill: var(--ink-2);
}

.erd-box {
  fill: var(--surface);
  stroke: var(--rule-strong);
  stroke-width: 1.2;
}

.erd-head {
  fill: var(--surface-2);
}

.erd-table.is-core .erd-head {
  fill: color-mix(in srgb, var(--accent) 14%, var(--surface));
}

.erd-title {
  font-weight: 700;
  fill: var(--ink) !important;
  font-size: 12.5px !important;
}

.erd-col.is-pk {
  fill: var(--ink) !important;
  font-weight: 700;
}

.erd-col.is-fk {
  fill: var(--accent) !important;
}

.erd-type {
  fill: var(--ink-3) !important;
  font-size: 10px !important;
}

.erd-table {
  cursor: pointer;
  transition: opacity var(--dur);
  outline: none;
}

.erd-table.is-dim {
  opacity: 0.3;
}

.erd-table:focus-visible .erd-box {
  stroke: var(--accent);
  stroke-width: 2;
}

.erd-link path {
  fill: none;
  stroke: var(--rule-strong);
  stroke-width: 1.4;
  transition: stroke var(--dur), stroke-width var(--dur);
}

.erd-link circle {
  stroke: var(--surface);
  stroke-width: 2;
}

.erd-end-many {
  fill: var(--accent);
}

.erd-end-one {
  fill: var(--highlight);
}

.erd-link.is-active path {
  stroke: var(--accent);
  stroke-width: 2.2;
}

.erd-legend {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-4);
  padding: 8px 14px 12px;
  direction: rtl;
  font-size: var(--fs-xs);
  color: var(--ink-2);
}

.erd-legend span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.erd-legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.erd-legend-dot.is-many {
  background: var(--accent);
}

.erd-legend-dot.is-one {
  background: var(--highlight);
  border: 1px solid var(--rule-strong);
}

@media (max-width: 700px) {
  .group-layout {
    grid-template-columns: minmax(0, 1fr);
  }

  .join-stage {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--s-3);
  }

  .join-side.join-right {
    grid-column: 1;
  }

  /* Stacked tables: row highlighting carries the matches, so connector lines are hidden. */
  .join-lines {
    display: none;
  }

  .join-header {
    flex-direction: column;
    align-items: flex-start;
  }
}