/* Two small step-through sims for the database post: row-versus-column storage
   and a parallel aggregate. Both share the same frame, tabs and footer. */

.dbsim {
  --dbsim-border: var(--color-border-subtle);
  --dbsim-muted: var(--color-text-muted);
  --dbsim-accent: var(--color-accent);
  margin: 0;
  border: 1px solid var(--dbsim-border);
  background: var(--color-bg);
  color: var(--color-text);
  font-size: 0.9rem;
  line-height: 1.45;
  transition: color 0.3s ease, background-color 0.3s ease, border-color 0.3s ease;
}

.dbsim *,
.dbsim *::before,
.dbsim *::after {
  box-sizing: border-box;
}

.dbsim__fallback {
  margin: 0;
  padding: 1.25rem;
  color: var(--color-text-secondary);
}

.dbsim.is-ready .dbsim__fallback {
  display: none;
}

/* --- head ---------------------------------------------------------------- */

.dbsim__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  padding: 0.9rem 1.1rem;
  border-bottom: 1px solid var(--dbsim-border);
  background: var(--color-bg-secondary);
}

.dbsim__title {
  margin: 0;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-family: var(--font-mono, monospace);
}

.dbsim__controls {
  display: flex;
  gap: 0.4rem;
}

.dbsim__btn {
  padding: 0.25rem 0.7rem;
  border: 1px solid var(--dbsim-border);
  background: var(--color-bg);
  color: var(--color-text-secondary);
  font-family: var(--font-mono, monospace);
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  cursor: pointer;
  transition: color 0.15s ease, border-color 0.15s ease;
}

.dbsim__btn:hover,
.dbsim__btn:focus-visible {
  color: var(--color-text);
  border-color: var(--dbsim-accent);
}

/* --- query + tabs -------------------------------------------------------- */

.dbsim__query {
  padding: 0.7rem 1.1rem;
  border-bottom: 1px solid var(--dbsim-border);
  font-family: var(--font-mono, monospace);
  font-size: 0.78rem;
  color: var(--color-text-secondary);
  overflow-x: auto;
  white-space: nowrap;
}

.dbsim__tabs {
  display: flex;
  border-bottom: 1px solid var(--dbsim-border);
}

.dbsim__tab {
  flex: 1;
  padding: 0.55rem 0.5rem;
  border: 0;
  border-right: 1px solid var(--dbsim-border);
  background: transparent;
  color: var(--dbsim-muted);
  font-family: var(--font-mono, monospace);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
  transition: color 0.15s ease, box-shadow 0.15s ease;
}

.dbsim__tab:last-child {
  border-right: 0;
}

.dbsim__tab:hover {
  color: var(--color-text);
}

.dbsim__tab.is-active {
  color: var(--color-text);
  box-shadow: inset 0 -2px 0 var(--dbsim-accent);
}

.dbsim__caption {
  margin: 0;
  padding: 0.9rem 1.1rem;
  min-height: 4.4rem;
  color: var(--color-text-secondary);
  font-size: 0.88rem;
}

.dbsim__stage {
  padding: 0 1.1rem 1.1rem;
}

/* --- footer stats -------------------------------------------------------- */

.dbsim__stats {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 1.2rem;
  padding: 0.7rem 1.1rem;
  border-top: 1px solid var(--dbsim-border);
  background: var(--color-bg-secondary);
  font-family: var(--font-mono, monospace);
  font-size: 0.7rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.dbsim__statlabel {
  color: var(--dbsim-muted);
  margin-right: 0.4rem;
}

.dbsim__stat strong {
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

/* --- sim 1: storage layouts ---------------------------------------------- */

.dbsim__stores {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.dbsim__storetitle {
  margin: 0 0 0.75rem;
  font-family: var(--font-mono, monospace);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.dbsim__storetitle span {
  display: block;
  margin-top: 0.15rem;
  font-weight: 400;
  text-transform: none;
  letter-spacing: 0;
  color: var(--dbsim-muted);
}

.dbsim__runs {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}

.dbsim__runlabel {
  display: block;
  margin-bottom: 0.2rem;
  font-family: var(--font-mono, monospace);
  font-size: 0.62rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--dbsim-muted);
}

/* A run is what sits contiguously on disk: one record for the row store, one
   field for the column store. The bracket makes that unit visible. */
.dbsim__track {
  display: grid;
  grid-template-columns: repeat(var(--dbsim-cols, 3), minmax(0, 1fr));
  gap: 2px;
  padding-left: 0.4rem;
  border-left: 2px solid var(--dbsim-border);
}

.dbsim__cell {
  padding: 0.3rem 0.35rem;
  border: 1px solid var(--dbsim-border);
  background: var(--color-bg);
  font-family: var(--font-mono, monospace);
  font-size: 0.68rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  transition: background-color 0.35s ease, border-color 0.35s ease, color 0.35s ease, opacity 0.35s ease;
}

.dbsim__cell.is-empty {
  border-style: dashed;
  color: transparent;
  background: transparent;
}

.dbsim__cell.is-writing,
.dbsim__cell.is-reading {
  border-color: var(--dbsim-accent);
  background: var(--color-highlight);
}

.dbsim__cell.is-stored {
  color: var(--color-text-secondary);
}

.dbsim__cell.is-kept {
  border-color: var(--dbsim-accent);
  background: var(--color-highlight);
  font-weight: 600;
}

.dbsim__cell.is-skipped {
  color: var(--dbsim-muted);
  opacity: 0.4;
}

/* --- sim 2: parallel aggregate ------------------------------------------- */

.dbsim__groups {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.dbsim__group {
  border: 1px solid var(--dbsim-border);
  transition: border-color 0.35s ease, opacity 0.35s ease;
}

.dbsim__grouphead {
  display: flex;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.35rem 0.6rem;
  border-bottom: 1px solid var(--dbsim-border);
  background: var(--color-bg-secondary);
  font-family: var(--font-mono, monospace);
  font-size: 0.62rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.dbsim__groupstats {
  color: var(--dbsim-muted);
}

.dbsim__table {
  width: 100%;
  margin: 0;
  border-collapse: collapse;
  font-family: var(--font-mono, monospace);
  font-size: 0.7rem;
}

.dbsim__table th,
.dbsim__table td {
  padding: 0.25rem 0.6rem;
  text-align: left;
  border: 0;
  transition: opacity 0.35s ease;
}

.dbsim__table th {
  font-weight: 400;
  color: var(--dbsim-muted);
  font-size: 0.62rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.dbsim__table td {
  color: var(--color-text-secondary);
}

.dbsim__amount {
  font-variant-numeric: tabular-nums;
}

.dbsim__group.is-kept,
.dbsim__group.is-scanning,
.dbsim__group.is-done {
  border-color: var(--dbsim-accent);
}

.dbsim__group.is-scanning .dbsim__amount,
.dbsim__group.is-done .dbsim__amount {
  color: var(--color-text);
  font-weight: 600;
}

.dbsim__group.is-pruned {
  border-style: dashed;
  opacity: 0.38;
}

/* Once the scan starts, only the amount column is leaving storage. */
.dbsim__group.is-amount-only th:not(:last-child),
.dbsim__group.is-amount-only td:not(:last-child) {
  opacity: 0.3;
}

.dbsim__group.is-pruned.is-amount-only th,
.dbsim__group.is-pruned.is-amount-only td {
  opacity: 1;
}

.dbsim__threads {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 0.9rem;
}

/* Cards are present from the first frame and light up when their stage comes
   round, so the sim never changes height while it runs. */
.dbsim__thread {
  flex: 1 1 8rem;
  padding: 0.5rem 0.6rem;
  border: 1px dashed var(--dbsim-border);
  background: transparent;
  color: var(--dbsim-muted);
  font-family: var(--font-mono, monospace);
  font-size: 0.68rem;
  transition: border-color 0.35s ease, background-color 0.35s ease, color 0.35s ease;
}

.dbsim__thread.is-active {
  border-style: solid;
  border-color: var(--dbsim-accent);
  background: var(--color-highlight);
  color: var(--color-text);
}

.dbsim__thread--result {
  flex-basis: 100%;
}

.dbsim__thread--result.is-active {
  background: transparent;
}

.dbsim__threadlabel {
  display: block;
  font-size: 0.6rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--dbsim-muted);
}

.dbsim__threadgroup {
  display: block;
  color: var(--color-text-secondary);
}

.dbsim__threadsum {
  display: block;
  margin-top: 0.15rem;
  font-size: 0.95rem;
  font-variant-numeric: tabular-nums;
}

.dbsim__threaddetail {
  display: block;
  color: var(--dbsim-muted);
}

/* --- narrow screens ------------------------------------------------------ */

@media (max-width: 640px) {
  .dbsim__stores {
    grid-template-columns: 1fr;
    gap: 1.25rem;
  }

  .dbsim__caption {
    min-height: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .dbsim *,
  .dbsim *::before,
  .dbsim *::after {
    transition: none !important;
  }
}