.structure-heading {
  align-items: flex-end;
}

.structure-tabs {
  display: grid;
  grid-template-columns: repeat(3, minmax(92px, 1fr));
  padding: 3px;
  background: var(--ink-800);
  border: 1px solid var(--border);
  border-radius: 5px;
}

.structure-tabs button {
  min-height: 36px;
  padding: 0 14px;
  color: var(--paper-400);
  background: transparent;
  border: 0;
  border-radius: 3px;
  font-size: 0.78rem;
  transition: color 180ms var(--ease-quart), background-color 180ms var(--ease-quart), transform 100ms var(--ease-quart);
}

.structure-tabs button:hover {
  color: var(--primary);
}

.structure-tabs button:active {
  transform: scale(0.98);
}

.structure-tabs button.is-active {
  color: #ffffff;
  background: var(--primary);
  font-weight: 600;
}

.structure-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 226px;
  align-items: start;
  gap: 14px;
}

.structure-canvas,
.control-goals,
.supporting-indicators {
  background: var(--ink-900);
  border: 1px solid var(--border);
  border-radius: 5px;
}

.structure-canvas {
  min-width: 0;
  padding: 18px;
  transition: opacity 180ms var(--ease-quart), transform 180ms var(--ease-quart);
}

.structure-canvas.is-switching {
  opacity: 0.74;
  transform: translateY(2px);
}

.structure-canvas-heading {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 20px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border);
}

.structure-canvas-heading h3,
.control-goals-heading h3,
.supporting-heading h3 {
  margin: 3px 0 0;
  font-size: 0.98rem;
  font-weight: 600;
}

.structure-canvas-heading > span {
  color: var(--paper-500);
  font-size: 0.7rem;
  text-align: right;
}

.structure-equation {
  display: grid;
  grid-template-columns: minmax(150px, 1fr) 28px minmax(150px, 1fr) 28px minmax(150px, 1fr);
  align-items: center;
  gap: 8px;
  max-width: 760px;
  margin: 22px auto 0;
}

.structure-summary-card {
  min-width: 0;
  padding: 14px 16px;
  background: var(--ink-850);
  border: 1px solid var(--border);
  border-radius: 5px;
  animation: structure-node-in 280ms var(--ease-out) both;
}

.structure-summary-card.is-primary {
  background: var(--primary-soft);
  border-color: #aebfed;
}

.structure-summary-card.is-risk {
  background: var(--risk-soft);
  border-color: #edc7c2;
}

.structure-summary-card.is-good {
  background: var(--good-soft);
  border-color: #bad9c9;
}

.structure-summary-card > span,
.structure-summary-card > small {
  display: block;
  color: var(--paper-500);
  font-size: 0.68rem;
}

.structure-summary-card > strong {
  display: block;
  margin: 5px 0 4px;
  color: var(--paper-100);
  font-size: 1.32rem;
  font-weight: 600;
}

.structure-operator {
  color: var(--paper-400);
  font-size: 1.5rem;
  font-weight: 500;
  text-align: center;
}

.structure-operator.is-risk {
  color: var(--risk);
}

.structure-operator.is-good {
  color: var(--good);
}

.structure-tree {
  position: relative;
  margin-top: 32px;
  padding-top: 24px;
}

.structure-tree::before {
  position: absolute;
  top: 0;
  left: 50%;
  width: 1px;
  height: 24px;
  background: var(--border-strong);
  content: "";
}

.structure-groups {
  position: relative;
  display: grid;
  grid-template-columns: repeat(var(--group-count), minmax(136px, 1fr));
  align-items: start;
  gap: 10px;
  padding-top: 18px;
}

.structure-groups::before {
  position: absolute;
  top: 0;
  right: calc(50% / var(--group-count));
  left: calc(50% / var(--group-count));
  height: 1px;
  background: var(--border-strong);
  content: "";
}

.structure-group {
  position: relative;
  min-width: 0;
  animation: structure-node-in 300ms var(--ease-out) both;
  animation-delay: calc(var(--node-i) * 35ms);
}

.structure-group::before {
  position: absolute;
  top: -18px;
  left: 50%;
  width: 1px;
  height: 18px;
  background: var(--border-strong);
  content: "";
}

.structure-group-card {
  min-height: 152px;
  padding: 13px;
  background: var(--ink-900);
  border: 1px solid var(--border-strong);
  border-top: 2px solid var(--primary);
  border-radius: 5px;
}

.structure-group-card.is-risk {
  border-top-color: var(--risk);
}

.structure-group-card.is-good {
  border-top-color: var(--good);
}

.structure-group-card > div,
.structure-group-card dl div,
.control-goal > div,
.control-goal dl div {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.structure-group-card > div span,
.structure-group-card > div small,
.structure-group-card dt,
.control-goal span,
.control-goal dt {
  color: var(--paper-500);
  font-size: 0.65rem;
  font-weight: 400;
}

.structure-group-card h3 {
  min-height: 38px;
  margin: 9px 0 2px;
  font-size: 0.82rem;
  font-weight: 600;
  line-height: 1.35;
}

.structure-group-card > strong {
  display: block;
  margin-bottom: 9px;
  font-size: 1.08rem;
  font-weight: 600;
}

.structure-group-card dl,
.control-goal dl {
  display: grid;
  gap: 3px;
  margin: 0;
}

.structure-group-card dd,
.control-goal dd {
  margin: 0;
  color: var(--paper-200);
  font-size: 0.66rem;
  font-weight: 500;
  text-align: right;
}

.structure-children {
  position: relative;
  display: grid;
  gap: 8px;
  margin-top: 18px;
  padding-left: 11px;
  border-left: 1px solid var(--border-strong);
}

.structure-children::before {
  position: absolute;
  top: -18px;
  left: -1px;
  width: 1px;
  height: 18px;
  background: var(--border-strong);
  content: "";
}

.structure-subject {
  position: relative;
  display: grid;
  min-width: 0;
  min-height: 92px;
  grid-template-columns: 1fr auto;
  align-content: center;
  gap: 3px 8px;
  padding: 11px 27px 11px 11px;
  color: var(--paper-100);
  background: var(--ink-850);
  border: 1px solid var(--border);
  border-radius: 4px;
  text-align: left;
  animation: structure-node-in 260ms var(--ease-out) both;
  animation-delay: calc(var(--child-i) * 28ms + 60ms);
  transition: border-color 180ms var(--ease-quart), background-color 180ms var(--ease-quart), transform 180ms var(--ease-quart);
}

.structure-subject::before {
  position: absolute;
  top: 50%;
  right: 100%;
  width: 12px;
  height: 1px;
  background: var(--border-strong);
  content: "";
}

.structure-subject:hover,
.structure-subject:focus-visible {
  z-index: 2;
  background: var(--primary-soft);
  border-color: #aebfed;
  transform: translateY(-2px);
}

.structure-subject > span {
  display: flex;
  min-width: 0;
  align-items: center;
  gap: 6px;
  overflow-wrap: anywhere;
  font-size: 0.73rem;
}

.structure-subject > span i {
  width: 6px;
  height: 6px;
  flex: 0 0 6px;
  background: var(--good);
  border-radius: 50%;
}

.structure-subject.is-risk > span i {
  background: var(--risk);
}

.structure-subject > strong {
  font-size: 0.78rem;
  font-weight: 600;
  white-space: nowrap;
}

.structure-subject > small {
  display: flex;
  grid-column: 1 / -1;
  justify-content: space-between;
  gap: 6px;
  color: var(--paper-500);
  font-size: 0.62rem;
}

.structure-subject.is-risk > small span:last-child {
  color: var(--risk);
}

.structure-arrow {
  position: absolute;
  top: 50%;
  right: 8px;
  width: 14px;
  height: 14px;
  color: var(--paper-500);
  transform: translateY(-50%);
  transition: transform 180ms var(--ease-quart);
}

.structure-subject:hover .structure-arrow,
.structure-subject:focus-visible .structure-arrow {
  transform: translate(2px, -50%);
}

.control-goals {
  padding: 18px 14px;
}

.control-goals-heading {
  padding-bottom: 13px;
  border-bottom: 1px solid var(--border);
}

#control-goal-list {
  display: grid;
  gap: 10px;
  margin-top: 14px;
}

.control-goal {
  padding: 14px;
  background: var(--ink-850);
  border: 1px solid var(--border);
  border-top: 2px solid var(--primary);
  border-radius: 4px;
  animation: structure-node-in 300ms var(--ease-out) both;
}

.control-goal.is-risk {
  border-top-color: var(--risk);
}

.control-goal.is-warn {
  border-top-color: var(--warn);
}

.control-goal.is-good {
  border-top-color: var(--good);
}

.control-goal > div svg {
  width: 15px;
  height: 15px;
  color: var(--primary);
}

.control-goal > strong {
  display: block;
  margin: 10px 0 9px;
  font-size: 1.28rem;
  font-weight: 600;
}

.supporting-indicators {
  margin-top: 14px;
  padding: 18px;
}

.supporting-heading {
  margin-bottom: 14px;
}

.supporting-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border: 1px solid var(--border);
  border-radius: 4px;
}

.supporting-grid article {
  min-width: 0;
  padding: 15px;
  border-right: 1px solid var(--border);
  animation: structure-node-in 280ms var(--ease-out) both;
  animation-delay: calc(var(--node-i) * 35ms);
}

.supporting-grid article:last-child {
  border-right: 0;
}

.supporting-grid span,
.supporting-grid small {
  display: block;
  color: var(--paper-500);
  font-size: 0.67rem;
}

.supporting-grid strong {
  display: block;
  margin: 6px 0 3px;
  font-size: 1.12rem;
  font-weight: 600;
}

@keyframes structure-node-in {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 1180px) {
  .structure-layout { grid-template-columns: 1fr; }
  .control-goals { display: grid; grid-template-columns: 190px 1fr; gap: 16px; }
  #control-goal-list { grid-template-columns: repeat(3, 1fr); margin-top: 0; }
}

@media (max-width: 900px) {
  .structure-canvas { overflow-x: auto; }
  .structure-canvas-heading,
  .structure-equation,
  .structure-tree { min-width: 720px; }
  .structure-equation { margin-inline: 0; }
  .structure-heading { align-items: flex-start; flex-direction: column; }
}

@media (max-width: 760px) {
  .structure-tabs { width: 100%; grid-template-columns: repeat(3, 1fr); }
  .structure-tabs button { min-width: 0; padding-inline: 8px; }
  .structure-layout { gap: 10px; }
  .structure-canvas { padding: 14px; }
  .control-goals { display: block; padding: 14px; }
  #control-goal-list { grid-template-columns: 1fr; margin-top: 14px; }
  .supporting-indicators { margin-top: 10px; padding: 14px; }
  .supporting-grid { grid-template-columns: repeat(2, 1fr); }
  .supporting-grid article:nth-child(2) { border-right: 0; }
  .supporting-grid article:nth-child(-n+2) { border-bottom: 1px solid var(--border); }
}

@media (max-width: 460px) {
  .structure-canvas-heading { align-items: flex-start; flex-direction: column; gap: 5px; }
  .structure-canvas-heading > span { text-align: left; }
  .supporting-grid { grid-template-columns: 1fr; }
  .supporting-grid article,
  .supporting-grid article:nth-child(2) { border-right: 0; border-bottom: 1px solid var(--border); }
  .supporting-grid article:last-child { border-bottom: 0; }
}

@media (prefers-reduced-motion: reduce) {
  .structure-summary-card,
  .structure-group,
  .structure-subject,
  .control-goal,
  .supporting-grid article { animation: none; }
}