.rectangle-sum-explorer {
  display: grid;
  gap: 1rem;
  min-width: 0;
}

.rectangle-sum-explorer__controls {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 12rem), 1fr));
  gap: .8rem;
  align-items: end;
}

.rectangle-sum-explorer__select-label,
.rectangle-sum-explorer__bound-label {
  display: grid;
  gap: .38rem;
  font-weight: 700;
}

.rectangle-sum-explorer__select,
.rectangle-sum-explorer__number-input {
  width: 100%;
  min-height: 44px;
  box-sizing: border-box;
  border: 1px solid var(--color-border, #cbd5e1);
  border-radius: .68rem;
  padding: .55rem .7rem;
  background: var(--color-surface, #fff);
  color: inherit;
  font: inherit;
}

.rectangle-sum-explorer__bounds {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: .55rem;
}

.rectangle-sum-explorer__n-control {
  display: grid;
  gap: .5rem;
}

.rectangle-sum-explorer__preset-row {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem;
}

.rectangle-sum-explorer__preset {
  min-height: 40px;
  border: 1px solid var(--color-border-strong, #94a3b8);
  border-radius: 999px;
  padding: .42rem .66rem;
  background: var(--color-surface, #fff);
  color: inherit;
  font: inherit;
  font-size: .86rem;
  font-weight: 750;
  cursor: pointer;
}

.rectangle-sum-explorer__preset[aria-pressed="true"] {
  border-color: var(--mode-accent, #3157a4);
  box-shadow: inset 0 0 0 1px var(--mode-accent, #3157a4);
}

.rectangle-sum-explorer__card,
.rectangle-sum-explorer__mapping {
  border: 1px solid var(--color-border, #d7dce5);
  border-radius: 1rem;
  background: var(--color-surface, #fff);
  overflow: hidden;
}

.rectangle-sum-explorer__card-heading {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: baseline;
  padding: .85rem 1rem .15rem;
}

.rectangle-sum-explorer__title,
.rectangle-sum-explorer__mapping-title {
  margin: 0;
  font-size: 1rem;
}

.rectangle-sum-explorer__expression {
  margin: 0;
  font-weight: 750;
  color: var(--color-text-muted, #526075);
  text-align: right;
}

.rectangle-sum-explorer__diagram { min-width: 0; }

.rectangle-sum-explorer .diagram-primitives__tone--rectangle-positive { color: #3567a8; }
.rectangle-sum-explorer .diagram-primitives__tone--rectangle-negative { color: #a84d35; }
.rectangle-sum-explorer .diagram-primitives__tone--sample { color: #7a4c9f; }
.rectangle-sum-explorer .diagram-primitives__tone--bound { color: #596579; }

.rectangle-sum-explorer__rectangle { pointer-events: none; }

.rectangle-sum-explorer__rectangle-outline {
  fill: none;
  stroke-width: 1.5px;
  opacity: .72;
}

.rectangle-sum-explorer__curve {
  stroke-width: 4px;
}

.rectangle-sum-explorer__bound-guide {
  opacity: .5;
  stroke-width: 1.6px;
}

.rectangle-sum-explorer__bound-label-svg,
.rectangle-sum-explorer__width-label {
  font-weight: 800;
  paint-order: stroke;
  stroke: var(--color-surface, #fff);
  stroke-width: 4px;
}

.rectangle-sum-explorer__readout {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 9rem), 1fr));
  gap: .6rem;
}

.rectangle-sum-explorer__metric {
  display: grid;
  gap: .18rem;
  min-width: 0;
  border: 1px solid var(--color-border, #d7dce5);
  border-radius: .8rem;
  padding: .65rem .75rem;
  background: var(--color-surface, #fff);
}

.rectangle-sum-explorer__metric span {
  color: var(--color-text-muted, #526075);
  font-size: .78rem;
  font-weight: 700;
}

.rectangle-sum-explorer__metric strong {
  font-size: 1rem;
  overflow-wrap: anywhere;
}

.rectangle-sum-explorer__mapping {
  padding: .9rem 1rem 1rem;
  display: grid;
  gap: .85rem;
}

.rectangle-sum-explorer__formula-flow {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: .5rem;
}

.rectangle-sum-explorer__formula {
  border-radius: .7rem;
  padding: .52rem .68rem;
  font-weight: 800;
  background: #f5f7fb;
  border: 1px solid var(--color-border, #d7dce5);
}

.rectangle-sum-explorer__formula--arrow {
  border: 0;
  background: transparent;
  color: var(--color-text-muted, #526075);
  font-size: .88rem;
}

.rectangle-sum-explorer__formula--integral {
  border-width: 2px;
  border-color: var(--mode-accent, #3157a4);
}

.rectangle-sum-explorer__component-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 11rem), 1fr));
  gap: .6rem;
}

.rectangle-sum-explorer__component {
  display: grid;
  gap: .3rem;
  border: 1px solid var(--color-border, #d7dce5);
  border-radius: .75rem;
  padding: .65rem .7rem;
  min-width: 0;
}

.rectangle-sum-explorer__component code {
  width: fit-content;
  border-radius: .4rem;
  padding: .18rem .35rem;
  background: #eef2f8;
  font-size: 1rem;
  font-weight: 800;
}

.rectangle-sum-explorer__component span {
  color: var(--color-text-muted, #526075);
  font-size: .84rem;
  overflow-wrap: anywhere;
}

.rectangle-sum-explorer__note {
  margin: 0;
  color: var(--color-text-muted, #526075);
  line-height: 1.45;
}

@media (max-width: 980px) {
  .rectangle-sum-explorer__controls {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .rectangle-sum-explorer__readout {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .rectangle-sum-explorer__component-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 720px) {
  .rectangle-sum-explorer__controls,
  .rectangle-sum-explorer__readout,
  .rectangle-sum-explorer__component-grid,
  .rectangle-sum-explorer__bounds {
    grid-template-columns: 1fr;
  }
  .rectangle-sum-explorer__card-heading {
    display: grid;
  }
  .rectangle-sum-explorer__expression { text-align: left; }
  .rectangle-sum-explorer__formula-flow {
    display: grid;
    align-items: stretch;
  }
  .rectangle-sum-explorer__formula { text-align: center; }
}